diff --git "a/44 \345\255\224\345\207\257\350\276\211/20230220\344\275\234\344\270\232.md" "b/44 \345\255\224\345\207\257\350\276\211/20230220\344\275\234\344\270\232.md" new file mode 100644 index 0000000000000000000000000000000000000000..0441b120414066383eee35ae60a024efd2e3547a --- /dev/null +++ "b/44 \345\255\224\345\207\257\350\276\211/20230220\344\275\234\344\270\232.md" @@ -0,0 +1,578 @@ +| 笔记 | | | +| ---- | ------------------------------------------------------------ | ------------------------------------------------------------ | +| | [2](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_2) | | +| | [3](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_3) | ### 1.查询 | +| | [4](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_4) | | +| | [5](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_5) | ~~~ mysql | +| | [6](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_6) | select *from 表名称； | +| | [7](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_7) | ~~~ | +| | [8](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_8) | | +| | [9](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_9) | ### 2.约束 | +| | [10](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_10) | | +| | [11](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_11) | ### 约束类型 | +| | [12](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_12) | | +| | [13](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_13) | * 键约束：主键约束、外键约束、唯一键约束 | +| | [14](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_14) | | +| | [15](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_15) | * Not NULL约束：非空约束 | +| | [16](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_16) | | +| | [17](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_17) | * Check约束：检查约束[8.0版本支持] | +| | [18](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_18) | | +| | [19](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_19) | * Default约束：默认值约束 | +| | [20](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_20) | | +| | [21](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_21) | * 自增是键约束字段的一个额外的属性。 | +| | [22](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_22) | | +| | [23](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_23) | ### （1）非空约束 | +| | [24](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_24) | | +| | [25](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_25) | 1、作用 | +| | [26](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_26) | | +| | [27](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_27) | 限定某个字段/某列的值不允许为空 | +| | [28](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_28) | | +| | [29](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_29) | 2、关键字：not null | +| | [30](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_30) | | +| | [31](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_31) | 3、特点 | +| | [32](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_32) | | +| | [33](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_33) | （1）只能某个列单独限定非空，不能组合非空 | +| | [34](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_34) | | +| | [35](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_35) | （2）一个表可以有很多列都分别限定了非空 | +| | [36](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_36) | | +| | [37](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_37) | 4、举例 | +| | [38](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_38) | | +| | [39](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_39) | ~~~ mysql | +| | [40](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_40) | create table 表名称( | +| | [41](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_41) | 字段名 数据类型 not null, | +| | [42](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_42) | 字段名 数据类型 not null, | +| | [43](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_43) | 字段名 数据类型 | +| | [44](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_44) | ); | +| | [45](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_45) | ~~~ | +| | [46](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_46) | | +| | [47](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_47) | 5、建表后设定非空约束 | +| | [48](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_48) | | +| | [49](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_49) | ~~~ mysql | +| | [50](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_50) | alter table 表名称 modify 【column】 字段名 数据类型 not null; | +| | [51](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_51) | ~~~ | +| | [52](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_52) | | +| | [53](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_53) | 6、如何删除非空约束 | +| | [54](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_54) | | +| | [55](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_55) | ~~~ mysql | +| | [56](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_56) | alter table 表名称 modify 【column】 字段名 数据类型; | +| | [57](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_57) | ~~~ | +| | [58](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_58) | | +| | [59](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_59) | ### （2）唯一键约束 | +| | [60](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_60) | | +| | [61](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_61) | 1、唯一键约束的作用 | +| | [62](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_62) | | +| | [63](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_63) | 单列唯一：用来限制某个字段/某列的值不能重复。 | +| | [64](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_64) | | +| | [65](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_65) | 组合唯一：用来限定几个字段的值组合不能重复。 | +| | [66](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_66) | | +| | [67](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_67) | 2、关键字：unique key | +| | [68](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_68) | | +| | [69](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_69) | 3、特点 | +| | [70](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_70) | | +| | [71](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_71) | （1）一个表可以有很多个唯一键约束， | +| | [72](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_72) | （2）每一个唯一键约束字段都会自动创建索引。 | +| | [73](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_73) | （3）唯一键约束允许为空 | +| | [74](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_74) | （4）唯一键约束也可以是复合唯一 | +| | [75](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_75) | （5）删除唯一键约束的索引来删除唯一键约束 | +| | [76](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_76) | 索引名默认是字段名，复合唯一默认是第一个字段名。 | +| | [77](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_77) | | +| | [78](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_78) | 4、建表后设定唯一键约束 | +| | [79](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_79) | | +| | [80](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_80) | ~~~ mysql | +| | [81](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_81) | alter table 表名称 add unique 【key】(字段名); | +| | [82](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_82) | ~~~ | +| | [83](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_83) | | +| | [84](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_84) | 5、如何删除唯一键约束 | +| | [85](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_85) | | +| | [86](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_86) | ~~~ mysql | +| | [87](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_87) | alter table 表名称 drop index 索引名; | +| | [88](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_88) | #删除唯一键约束需要手动删除对应的索引 | +| | [89](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_89) | ~~~ | +| | [90](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_90) | | +| | [91](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_91) | 6、如何查看唯一键约束 | +| | [92](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_92) | | +| | [93](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_93) | ~~~ mysql | +| | [94](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_94) | desc 表名称; | +| | [95](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_95) | | +| | [96](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_96) | show create table 表名称; | +| | [97](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_97) | | +| | [98](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_98) | show index from 表名称; #查看表的索引信息 | +| | [99](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_99) | ~~~ | +| | [100](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_100) | | +| | [101](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_101) | 7、如何查看表的索引 | +| | [102](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_102) | | +| | [103](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_103) | ~~~ mysql | +| | [104](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_104) | show index from 表名称; | +| | [105](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_105) | ~~~ | +| | [106](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_106) | | +| | [107](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_107) | # 主键约束！！！！！ | +| | [108](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_108) | | +| | [109](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_109) | ### 1、主键约束的作用 | +| | [110](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_110) | | +| | [111](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_111) | 用来唯一的确定一条记录 | +| | [112](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_112) | | +| | [113](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_113) | ### 2、关键字：primary key | +| | [114](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_114) | | +| | [115](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_115) | ### 3、特点 | +| | [116](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_116) | | +| | [117](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_117) | （1）唯一并且非空 | +| | [118](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_118) | | +| | [119](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_119) | （2）一个表最多只能有一个主键约束 | +| | [120](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_120) | | +| | [121](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_121) | （3）如果主键是由多列组成，可以使用复合主键 | +| | [122](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_122) | | +| | [123](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_123) | （4）主键列会自动创建索引（能够根据主键查询的，就根据主键查询，效率更高） | +| | [124](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_124) | | +| | [125](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_125) | 主键列的唯一并且非空是约束的概念，但是mysql会给每个表的主键列创建索引，会开辟单独的物理空间来存储每一个主键的目录表（Btree结构）。这样设计的意义，可以根据主键快速查询到某一行的记录。 | +| | [126](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_126) | | +| | [127](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_127) | （5）如果删除主键约束了，主键约束对应的索引就自动删除了。 | +| | [128](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_128) | | +| | [129](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_129) | ### 4、唯一键约束和主键约束区别 | +| | [130](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_130) | | +| | [131](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_131) | （1）唯一键约束一个表可以有好几个， | +| | [132](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_132) | 但是主键约束只有一个 | +| | [133](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_133) | （2）唯一键约束本身不带非空限制，如果需要非空，需要单独定义。 | +| | [134](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_134) | 主键约束不用再定义NOT NULL，自身就带非空限制。 | +| | [135](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_135) | | +| | [136](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_136) | ### 5、如何指定主键约束 | +| | [137](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_137) | | +| | [138](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_138) | （1）建表时指定主键约束 | +| | [139](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_139) | | +| | [140](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_140) | ~~~ mysql | +| | [141](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_141) | create table 表名称( | +| | [142](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_142) | 字段名 数据类型 primary key, | +| | [143](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_143) | 字段名 数据类型, | +| | [144](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_144) | 字段名 数据类型 | +| | [145](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_145) | ); | +| | [146](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_146) | create table 表名称( | +| | [147](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_147) | 字段名 数据类型, | +| | [148](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_148) | 字段名 数据类型, | +| | [149](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_149) | 字段名 数据类型, | +| | [150](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_150) | primary key(字段名) | +| | [151](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_151) | ); | +| | [152](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_152) | ~~~ | +| | [153](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_153) | | +| | [154](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_154) | （2）建表后增加主键约束 | +| | [155](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_155) | | +| | [156](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_156) | ~~~ mysql | +| | [157](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_157) | alter table 表名称 add primary key(字段列表); #字段列表可以是一个字段，也可以是多个字段，如果是多个字段的话，是复合主键 | +| | [158](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_158) | ~~~ | +| | [159](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_159) | | +| | [160](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_160) | ### 6、复合主键 | +| | [161](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_161) | | +| | [162](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_162) | ~~~ mysql | +| | [163](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_163) | create table 表名称( | +| | [164](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_164) | 字段名 数据类型, | +| | [165](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_165) | 字段名 数据类型, | +| | [166](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_166) | 字段名 数据类型, | +| | [167](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_167) | primary key(字段名1,字段名2) #表示字段1和字段2的组合是唯一的，也可以有更多个字段 | +| | [168](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_168) | ); | +| | [169](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_169) | ~~~ | +| | [170](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_170) | | +| | [171](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_171) | 7、如何删除主键约束 | +| | [172](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_172) | | +| | [173](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_173) | ~~~ mysql | +| | [174](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_174) | alter table 表名称 drop primary key; | +| | [175](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_175) | ~~~ | +| | [176](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_176) | | +| | [177](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_177) | ## 外键约束 | +| | [178](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_178) | | +| | [179](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_179) | ### 1、作用 | +| | [180](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_180) | | +| | [181](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_181) | 限定某个表的某个字段的引用完整性， | +| | [182](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_182) | | +| | [183](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_183) | 比如：员工表的员工所在部门的选择，必须在部门表能找到对应的部分。 | +| | [184](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_184) | | +| | [185](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_185) | ### 2、关键字：foreign key | +| | [186](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_186) | | +| | [187](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_187) | ### 3、如何使用外键约束 | +| | [188](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_188) | | +| | [189](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_189) | （1）建表时 | +| | [190](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_190) | | +| | [191](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_191) | ~~~ mysql | +| | [192](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_192) | create table 主表名称( | +| | [193](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_193) | 字段1 数据类型 primary key, | +| | [194](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_194) | 字段2 数据类型 | +| | [195](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_195) | ); | +| | [196](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_196) | | +| | [197](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_197) | create table 从表名称( | +| | [198](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_198) | 字段1 数据类型 primary key, | +| | [199](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_199) | 字段2 数据类型, | +| | [200](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_200) | foreign key （从表的某个字段) references 主表名(被参考字段) | +| | [201](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_201) | ); | +| | [202](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_202) | | +| | [203](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_203) | ~~~ | +| | [204](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_204) | | +| | [205](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_205) | （2）建表后 | +| | [206](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_206) | | +| | [207](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_207) | ~~~ mysql | +| | [208](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_208) | alter table 从表名称 add foreign key (从表的字段) references 主表（被引用字段) 【on update xx】【on delete xx】; | +| | [209](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_209) | ~~~ | +| | [210](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_210) | | +| | [211](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_211) | ### 4、如何查看外键约束名 | +| | [212](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_212) | | +| | [213](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_213) | ~~~ mysql | +| | [214](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_214) | desc 从表名称; #可以看到外键约束，但看不到外键约束名 | +| | [215](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_215) | | +| | [216](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_216) | show create table 从表名称; #可以看到外键约束名 | +| | [217](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_217) | | +| | [218](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_218) | SELECT * FROM information_schema.table_constraints WHERE table_name = '表名称'; | +| | [219](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_219) | ~~~ | +| | [220](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_220) | | +| | [221](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_221) | ### 5、如何查看外键字段索引 | +| | [222](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_222) | | +| | [223](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_223) | ~~~ mysql | +| | [224](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_224) | show index from 表名称; #查看某个表的索引名 | +| | [225](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_225) | ~~~ | +| | [226](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_226) | | +| | [227](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_227) | ### 6、如何删除外键约束 | +| | [228](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_228) | | +| | [229](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_229) | ~~~ mysql | +| | [230](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_230) | (1)第一步先查看约束名和删除外键约束 | +| | [231](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_231) | SELECT * FROM information_schema.table_constraints WHERE table_name = '表名称';#查看某个表的约束名 | +| | [232](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_232) | | +| | [233](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_233) | alter table 从表名 drop foreign key 外键约束名; | +| | [234](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_234) | | +| | [235](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_235) | （2）第二步查看索引名和删除索引 | +| | [236](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_236) | show index from 表名称; #查看某个表的索引名 | +| | [237](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_237) | | +| | [238](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_238) | alter table 从表名 drop index 索引名; | +| | [239](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_239) | ~~~ | +| | [240](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_240) | | +| | [241](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_241) | | +| | [242](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_242) | | +| | [243](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_243) | | +| | [244](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_244) | | +| | [245](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_245) | # 作业 | +| | [246](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_246) | | +| | [247](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_247) | ### 第一题 | +| | [248](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_248) | | +| | [249](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_249) | ~~~ mysql | +| | [250](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_250) | ##第1题 | +| | [251](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_251) | #1、创建数据库test01_company | +| | [252](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_252) | SHOW DATABASES; | +| | [253](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_253) | CREATE DATABASE test01_company; | +| | [254](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_254) | use test01_company; | +| | [255](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_255) | | +| | [256](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_256) | #2、创建表格offices | +| | [257](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_257) | CREATE TABLE offices( | +| | [258](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_258) | officeCode int, | +| | [259](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_259) | city varchar(30), | +| | [260](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_260) | address varchar(50), | +| | [261](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_261) | country varchar(50), | +| | [262](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_262) | postalCode varchar(25) | +| | [263](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_263) | ); | +| | [264](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_264) | | +| | [265](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_265) | \| 字段名 \| 数据类型 \| | +| | [266](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_266) | \| ---------- \| ----------- \| | +| | [267](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_267) | \| officeCode \| int \| | +| | [268](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_268) | \| city \| varchar(30) \| | +| | [269](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_269) | \| address \| varchar(50) \| | +| | [270](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_270) | \| country \| varchar(50) \| | +| | [271](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_271) | \| postalCode \| varchar(25) \| | +| | [272](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_272) | | +| | [273](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_273) | #3、创建表格employees | +| | [274](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_274) | CREATE TABLE employees( | +| | [275](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_275) | empNum int(11), | +| | [276](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_276) | lastName varchar(50), | +| | [277](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_277) | firstName varchar(50), | +| | [278](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_278) | mobile varchar(25), | +| | [279](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_279) | code int, | +| | [280](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_280) | jobTitle varchar(50), | +| | [281](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_281) | birth date, | +| | [282](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_282) | Note varchar(255), | +| | [283](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_283) | Sex varchar(5) | +| | [284](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_284) | ); | +| | [285](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_285) | \| 字段名 \| 数据类型 \| | +| | [286](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_286) | \| --------- \| ------------- \| | +| | [287](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_287) | \| empNum \| int(11) \| | +| | [288](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_288) | \| lastName \| varchar（50） \| | +| | [289](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_289) | \| firstName \| varchar(50) \| | +| | [290](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_290) | \| mobile \| varchar(25) \| | +| | [291](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_291) | \| code \| int \| | +| | [292](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_292) | \| jobTitle \| varchar(50) \| | +| | [293](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_293) | \| birth \| date \| | +| | [294](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_294) | \| Note \| varchar(255) \| | +| | [295](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_295) | \| Sex \| varchar(5) \| | +| | [296](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_296) | | +| | [297](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_297) | #**要求4：**将表employees的mobile字段修改到code字段后面。 | +| | [298](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_298) | | +| | [299](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_299) | ALTER TABLE employees MODIFY mobile varchar(25) AFTER code; | +| | [300](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_300) | | +| | [301](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_301) | #**要求5：**将表employees的birth字段改名为birthday; | +| | [302](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_302) | | +| | [303](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_303) | ALTER TABLE employees CHANGE birth birthday date; | +| | [304](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_304) | | +| | [305](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_305) | #**要求6：**修改sex字段，数据类型为char（1）。 | +| | [306](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_306) | | +| | [307](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_307) | ALTER TABLE employees MODIFY sex char(1); | +| | [308](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_308) | | +| | [309](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_309) | #**要求7：**删除字段note； | +| | [310](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_310) | | +| | [311](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_311) | ALTER TABLE employees DROP note; | +| | [312](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_312) | | +| | [313](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_313) | #**要求8：**增加字段名favoriate_activity，数据类型为varchar（100）； | +| | [314](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_314) | | +| | [315](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_315) | ALTER TABLE employees ADD favoriate_activity varchar(100); | +| | [316](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_316) | | +| | [317](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_317) | #**要求9：**将表employees的名称修改为 employees_info | +| | [318](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_318) | | +| | [319](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_319) | ALTER TABLE employees RENAME TO employees_info; | +| | [320](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_320) | | +| | [321](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_321) | | +| | [322](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_322) | | +| | [323](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_323) | | +| | [324](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_324) | ~~~ | +| | [325](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_325) | | +| | [326](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_326) | # 第二题 | +| | [327](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_327) | | +| | [328](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_328) | ~~~ mysql | +| | [329](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_329) | ## 第2题 | +| | [330](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_330) | | +| | [331](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_331) | #1、创建数据库test02db | +| | [332](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_332) | SHOW DATABASES; | +| | [333](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_333) | CREATE DATABASE test02db charset utf8; | +| | [334](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_334) | USE test02db; | +| | [335](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_335) | #2、创建表格pet | +| | [336](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_336) | CREATE TABLE pet( | +| | [337](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_337) | name varchar(20) COMMENT '宠物名称', | +| | [338](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_338) | owner varchar(20) COMMENT '宠物主人', | +| | [339](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_339) | species varchar(20) COMMENT '种类', | +| | [340](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_340) | sex char(1) COMMENT '性别', | +| | [341](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_341) | birth year COMMENT '出生日期', | +| | [342](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_342) | death year COMMENT '死亡日期' | +| | [343](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_343) | ); | +| | [344](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_344) | | +| | [345](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_345) | \| 字段名 \| 字段说明 \| 数据类型 \| | +| | [346](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_346) | \| ------- \| -------- \| ----------- \| | +| | [347](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_347) | \| name \| 宠物名称 \| varchar(20) \| | +| | [348](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_348) | \| owner \| 宠物主人 \| varchar(20) \| | +| | [349](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_349) | \| species \| 种类 \| varchar(20) \| | +| | [350](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_350) | \| sex \| 性别 \| char(1) \| | +| | [351](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_351) | \| birth \| 出生日期 \| year \| | +| | [352](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_352) | \| death \| 死亡日期 \| year \| | +| | [353](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_353) | | +| | [354](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_354) | #3、添加记录 | +| | [355](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_355) | INSERT INTO pet(name,owner,species,sex,birth,death) | +| | [356](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_356) | VALUES('Fluffy','harold','Cat','f ',2003,2010), | +| | [357](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_357) | ('Claws','gwen','Cat','m ',2004,NULL), | +| | [358](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_358) | ('Buffy','null','Dog','f',2009,NULL), | +| | [359](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_359) | ('Fang','benny','Dog','m',2000,NULL), | +| | [360](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_360) | ('bowser','diane','Dog','m',2003,2009), | +| | [361](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_361) | ('Chirpy',NULL,'Bird','f',2008,NULL); | +| | [362](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_362) | SELECT *FROM pet; | +| | [363](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_363) | \| name \| owner \| species \| sex \| birth \| death \| | +| | [364](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_364) | \| ------ \| ------ \| ------- \| ---- \| ----- \| ----- \| | +| | [365](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_365) | \| Fluffy \| harold \| Cat \| f \| 2003 \| 2010 \| | +| | [366](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_366) | \| Claws \| gwen \| Cat \| m \| 2004 \| \| | +| | [367](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_367) | \| Buffy \| \| Dog \| f \| 2009 \| \| | +| | [368](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_368) | \| Fang \| benny \| Dog \| m \| 2000 \| \| | +| | [369](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_369) | \| bowser \| diane \| Dog \| m \| 2003 \| 2009 \| | +| | [370](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_370) | \| Chirpy \| \| Bird \| f \| 2008 \| \| | +| | [371](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_371) | | +| | [372](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_372) | #4、 添加字段主人的生日owner_birth。 | +| | [373](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_373) | | +| | [374](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_374) | ALTER TABLE pet ADD owner_birth date; | +| | [375](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_375) | DESC pet; | +| | [376](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_376) | | +| | [377](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_377) | #5、 将名称为Claws的猫的主人改为kevin | +| | [378](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_378) | | +| | [379](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_379) | UPDATE pet SET owner='kevin' WHERE name='Claws'; | +| | [380](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_380) | SELECT *FROM pet; | +| | [381](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_381) | | +| | [382](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_382) | #6、 将没有死的狗的主人改为duck | +| | [383](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_383) | | +| | [384](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_384) | UPDATE pet SET owner='duck' WHERE species='dog' AND death IS NULL; | +| | [385](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_385) | SELECT *FROM pet; | +| | [386](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_386) | | +| | [387](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_387) | #7、 查询没有主人的宠物的名字； | +| | [388](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_388) | | +| | [389](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_389) | SELECT NAME FROM pet WHERE owner IS NULL; | +| | [390](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_390) | | +| | [391](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_391) | #8、 查询已经死了的cat的姓名，主人，以及去世时间； | +| | [392](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_392) | | +| | [393](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_393) | SELECT name,owner,death FROM pet WHERE species='Cat' AND death IS NOT NULL; | +| | [394](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_394) | | +| | [395](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_395) | #9、 删除已经死亡的狗 | +| | [396](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_396) | | +| | [397](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_397) | DELETE FROM pet WHERE species='dog' AND death IS NOT NULL; | +| | [398](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_398) | | +| | [399](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_399) | #10、查询所有宠物信息 | +| | [400](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_400) | | +| | [401](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_401) | SELECT *FROM pet; | +| | [402](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_402) | | +| | [403](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_403) | ~~~ | +| | [404](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_404) | | +| | [405](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_405) | | +| | [406](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_406) | | +| | [407](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_407) | # 第三题 | +| | [408](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_408) | | +| | [409](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_409) | ~~~mysql | +| | [410](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_410) | ## 第3题 | +| | [411](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_411) | #1、创建数据库：test03_company | +| | [412](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_412) | SHOW DATABASES; | +| | [413](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_413) | CREATE DATABASE test03_company charset utf8; | +| | [414](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_414) | USE test03_company; | +| | [415](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_415) | #2、在此数据库下创建如下3表，数据类型，宽度，是否为空根据实际情况自己定义。 | +| | [416](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_416) | A． 部门表（department）：部门编号（depid），部门名称（depname），部门简介（deinfo）；其中部门编号为主键。 | +| | [417](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_417) | DROP TABLE department; | +| | [418](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_418) | 部门表： | +| | [419](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_419) | \| 部门编号 \| 部门名称 \| 部门简介 \| | +| | [420](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_420) | \| -------- \| -------- \| ------------ \| | +| | [421](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_421) | \| 111 \| 生产部 \| Null \| | +| | [422](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_422) | \| 222 \| 销售部 \| Null \| | +| | [423](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_423) | \| 333 \| 人事部 \| 人力资源管理 \| | +| | [424](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_424) | CREATE TABLE department( | +| | [425](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_425) | depid INT primary key, | +| | [426](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_426) | depname CHAR(3) , | +| | [427](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_427) | deinfo VARCHAR(10) | +| | [428](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_428) | ); | +| | [429](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_429) | INSERT INTO department(depid,depname,deinfo) | +| | [430](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_430) | VALUES(111,'生产部',NULL), | +| | [431](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_431) | (222,'销售部',NULL), | +| | [432](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_432) | (333,'人事部','人力资源管理'); | +| | [433](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_433) | SELECT *FROM department; | +| | [434](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_434) | | +| | [435](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_435) | | +| | [436](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_436) | | +| | [437](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_437) | | +| | [438](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_438) | B． 雇员表（emoloyee）：雇员编号（empid），姓名（name），性别（sex），职称（title），出生日期（birthday），所在部门编号（depid）；其中 | +| | [439](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_439) | * 雇员编号为主键； | +| | [440](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_440) | * 部门编号为外键，外键约束等级为（on update cascade 和on delete set null）； | +| | [441](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_441) | * 性别默认为男； | +| | [442](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_442) | 雇员表： | +| | [443](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_443) | \| 雇员编号 \| 姓名 \| 性别 \| 职称 \| 出生日期 \| 所在部门编号 \| | +| | [444](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_444) | \| -------- \| ---- \| ---- \| ---------- \| ---------- \| ------------ \| | +| | [445](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_445) | \| 1001 \| 张三 \| 男 \| 高级工程师 \| 1975-1-1 \| 111 \| | +| | [446](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_446) | \| 1002 \| 李四 \| 女 \| 助工 \| 1985-1-1 \| 111 \| | +| | [447](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_447) | \| 1003 \| 王五 \| 男 \| 工程师 \| 1978-11-11 \| 222 \| | +| | [448](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_448) | \| 1004 \| 张六 \| 男 \| 工程师 \| 1999-1-1 \| 222 \| | +| | [449](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_449) | # department中的depid为主表 | +| | [450](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_450) | DROP TABLE emoloyee; | +| | [451](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_451) | CREATE TABLE emoloyee( | +| | [452](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_452) | empid INT primary key, | +| | [453](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_453) | name VARCHAR(5), | +| | [454](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_454) | #sex char（1） NOT NULL DEFAULT '男',也可以 | +| | [455](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_455) | sex enum('男','女') NOT NULL DEFAULT '男', | +| | [456](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_456) | title VARCHAR(6), | +| | [457](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_457) | birthday date, | +| | [458](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_458) | # 外键约束，更新和删除 | +| | [459](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_459) | depid INT, | +| | [460](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_460) | foreign key(depid) references department(depid) on update cascade on delete set null | +| | [461](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_461) | ); | +| | [462](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_462) | INSERT INTO emoloyee(empid,name,sex,title,birthday,depid) | +| | [463](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_463) | VALUES(1001,'张三','男','高级工程师','1975-1-1',111), | +| | [464](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_464) | (1002,'李四','女','助工','1985-1-1',111), | +| | [465](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_465) | (1003,'王五','男','工程师','1978-11-11',222), | +| | [466](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_466) | (1004,'张六','男','工程师','1999-1-1',222); | +| | [467](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_467) | SELECT *FROM emoloyee; | +| | [468](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_468) | | +| | [469](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_469) | | +| | [470](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_470) | | +| | [471](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_471) | | +| | [472](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_472) | 3、给工资表（salary）的雇员编号（empid）增加外键约束，外键约束等级为（on update cascade 和on delete cascade） | +| | [473](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_473) | C． 工资表（salary）：雇员编号（empid），基本工资（basesalary），职务工资（titlesalary），扣除（deduction）。其中雇员编号为主键。 | +| | [474](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_474) | 工资表： | +| | [475](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_475) | \| 雇员编号 \| 基本工资 \| 职务工资 \| 扣除 \| | +| | [476](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_476) | \| -------- \| -------- \| -------- \| ---- \| | +| | [477](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_477) | \| 1001 \| 2200 \| 1100 \| 200 \| | +| | [478](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_478) | \| 1002 \| 1200 \| 200 \| NULL \| | +| | [479](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_479) | \| 1003 \| 2900 \| 700 \| 200 \| | +| | [480](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_480) | \| 1004 \| 1950 \| 700 \| 150 \| | +| | [481](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_481) | CREATE TABLE salary( | +| | [482](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_482) | empid INT PRIMARY KEY, | +| | [483](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_483) | foreign key(empid) references emoloyee(empid)on update cascade on delete cascade, | +| | [484](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_484) | basesalary INT, | +| | [485](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_485) | titlesalary INT, | +| | [486](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_486) | deduction INT | +| | [487](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_487) | ); | +| | [488](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_488) | INSERT INTO salary(empid,basesalary,titlesalary,deduction) | +| | [489](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_489) | VALUES(1001,2200,1100,200), | +| | [490](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_490) | (1002,1200,200,NULL), | +| | [491](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_491) | (1003,2900,700,200), | +| | [492](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_492) | (1004,1950,700,150); | +| | [493](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_493) | SELECT *FROM salary; | +| | [494](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_494) | | +| | [495](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_495) | ~~~ | +| | [496](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_496) | | +| | [497](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_497) | | +| | [498](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_498) | | +| | [499](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_499) | # 第四题 | +| | [500](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_500) | | +| | [501](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_501) | ~~~ mysql | +| | [502](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_502) | | +| | [503](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_503) | | +| | [504](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_504) | ## 第4题 | +| | [505](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_505) | | +| | [506](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_506) | #1、创建一个数据库：test04_school | +| | [507](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_507) | SHOW DATABASES; | +| | [508](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_508) | CREATE DATABASE test04_school charset utf8; | +| | [509](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_509) | USE test04_school; | +| | [510](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_510) | #2、创建如下表格 | +| | [511](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_511) | #表1 Department表的定义 | +| | [512](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_512) | \| **字段名** \| **字段描述** \| **数据类型** \| **主键** \| **外键** \| **非空** \| **唯一** \| | +| | [513](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_513) | \| ---------- \| ------------ \| ------------ \| -------- \| -------- \| -------- \| -------- \| | +| | [514](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_514) | \| DepNo \| 部门号 \| int(10) \| 是 \| 否 \| 是 \| 是 \| | +| | [515](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_515) | \| DepName \| 部门名称 \| varchar(20) \| 否 \| 否 \| 是 \| 否 \| | +| | [516](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_516) | \| DepNote \| 部门备注 \| Varchar(50) \| 否 \| 否 \| 否 \| 否 \| | +| | [517](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_517) | #3、添加记录 | +| | [518](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_518) | \| **DepNo** \| **DepName** \| **DepNote** \| | +| | [519](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_519) | \| --------- \| ----------- \| ------------------ \| | +| | [520](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_520) | \| 601 \| 软件技术系 \| 软件技术等专业 \| | +| | [521](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_521) | \| 602 \| 网络技术系 \| 多媒体技术等专业 \| | +| | [522](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_522) | \| 603 \| 艺术设计系 \| 广告艺术设计等专业 \| | +| | [523](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_523) | \| 604 \| 管理工程系 \| 连锁经营管理等专业 \| | +| | [524](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_524) | CREATE TABLE Department( | +| | [525](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_525) | DepNo int(10) COMMENT '部门号' PRIMARY KEY NOT NULL UNIQUE, | +| | [526](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_526) | DepName varchar(20) COMMENT '部门名称' NOT NULL, | +| | [527](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_527) | DepNote varchar(50) COMMENT '部门备注' | +| | [528](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_528) | ); | +| | [529](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_529) | INSERT INTO Department(DepNo,DepName,DepNote) | +| | [530](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_530) | VALUES(601,'软件技术系','软件技术等专业'), | +| | [531](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_531) | (602,'网络技术系','多媒体技术等专业'), | +| | [532](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_532) | (603,'艺术设计系','广告艺术设计等专业'), | +| | [533](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_533) | (604,'管理工程系','连锁经营管理等专业'); | +| | [534](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_534) | SELECT *FROM Department; | +| | [535](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_535) | #表2 Teacher表的定义 | +| | [536](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_536) | \| **字段名** \| **字段描述** \| **数据类型** \| **主键** \| **外键** \| **非空** \| **唯一** \| | +| | [537](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_537) | \| ---------- \| ------------ \| ------------ \| -------- \| -------- \| -------- \| -------- \| | +| | [538](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_538) | \| Number \| 教工号 \| int \| 是 \| 否 \| 是 \| 是 \| | +| | [539](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_539) | \| Name \| 姓名 \| varchar(30) \| 否 \| 否 \| 是 \| 否 \| | +| | [540](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_540) | \| Sex \| 性别 \| varchar(4) \| 否 \| 否 \| 否 \| 否 \| | +| | [541](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_541) | \| Birth \| 出生日期 \| date \| 否 \| 否 \| 否 \| 否 \| | +| | [542](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_542) | \| DepNo \| 部门号 \| int \| 否 \| 是 \| 否 \| 否 \| | +| | [543](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_543) | \| Salary \| 工资 \| float \| 否 \| 否 \| 否 \| 否 \| | +| | [544](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_544) | \| Address \| 家庭住址 \| varchar(100) \| 否 \| 否 \| 否 \| 否 \| | +| | [545](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_545) | | +| | [546](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_546) | #3、添加记录 | +| | [547](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_547) | | +| | [548](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_548) | \| **Number** \| **Name** \| **Sex** \| **Birth** \| **DepNo** \| **Salary** \| **Address** \| | +| | [549](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_549) | \| ---------- \| -------- \| ------- \| ---------- \| --------- \| ---------- \| ------------ \| | +| | [550](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_550) | \| 2001 \| Tom \| 女 \| 1970-01-10 \| 602 \| 4500 \| 四川省绵阳市 \| | +| | [551](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_551) | \| 2002 \| Lucy \| 男 \| 1983-12-18 \| 601 \| 2500 \| 北京市昌平区 \| | +| | [552](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_552) | \| 2003 \| Mike \| 男 \| 1990-06-01 \| 604 \| 1500 \| 重庆市渝中区 \| | +| | [553](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_553) | \| 2004 \| James \| 女 \| 1980-10-20 \| 602 \| 3500 \| 四川省成都市 \| | +| | [554](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_554) | \| 2005 \| Jack \| 男 \| 1975-05-30 \| 603 \| 1200 \| 重庆市南岸区 \| | +| | [555](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_555) | | +| | [556](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_556) | | +| | [557](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_557) | DROP TABLE Teacher; | +| | [558](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_558) | CREATE TABLE Teacher( | +| | [559](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_559) | Number int COMMENT '教工号' PRIMARY KEY NOT NULL UNIQUE, | +| | [560](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_560) | Name varchar(30) COMMENT '姓名' NOT NULL, | +| | [561](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_561) | Sex varchar(4) COMMENT '性别', | +| | [562](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_562) | Birth date COMMENT '出生日期', | +| | [563](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_563) | DepNo int COMMENT '部门号', | +| | [564](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_564) | FOREIGN KEY(DepNo) references Department(DepNo), | +| | [565](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_565) | Salary float COMMENT '工资', | +| | [566](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_566) | Address varchar(100) COMMENT '家庭住址' | +| | [567](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_567) | ); | +| | [568](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_568) | INSERT INTO Teacher(Number,Name,Sex,Birth,DepNo,Salary,Address) | +| | [569](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_569) | VALUES(2001,'Tom','女','1970-01-10',602,4500,'四川省绵阳市'), | +| | [570](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_570) | (2002,'Lucy','男','1983-12-18',601,2500,'北京市昌平区'), | +| | [571](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_571) | (2003,'Mike','男','1990-06-01',604,1500,'重庆市渝中区'), | +| | [572](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_572) | (2004,'James','女','1980-10-20',602,3500,'四川省成都市'), | +| | [573](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_573) | (2005,'Jack','男','1975-05-30',603,1200,'重庆市南岸区'); | +| | [574](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_574) | #4、用SELECT语句查询Teacher表的所有记录。 | +| | [575](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_575) | | +| | [576](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_576) | SELECT *FROM Teacher; | +| | [577](https://gitee.com/zhang-longten/mysql-base/commit/002f86e5e8ed4ac8f2e357e15a005b674f5712f8#fcb55745e576decc16a4e24391a662ce024b29c9_0_577) | ~~~ | \ No newline at end of file