From 958d7d81ad9750fd43bd9bdaa1a6262a50c773f5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E6=96=BD=E6=88=90=E6=98=8A?= <2758157909@qq.com> Date: Tue, 7 Mar 2023 19:57:30 +0800 Subject: [PATCH] =?UTF-8?q?=E6=96=BD=E6=88=90=E6=98=8A=E5=AD=90=E6=9F=A5?= =?UTF-8?q?=E8=AF=A2=E4=BD=9C=E4=B8=9A?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ...6 \345\255\220\346\237\245\350\257\242.md" | 150 ++++++++++++++++++ 1 file changed, 150 insertions(+) create mode 100644 "45 \346\226\275\346\210\220\346\230\212/20230306 \345\255\220\346\237\245\350\257\242.md" diff --git "a/45 \346\226\275\346\210\220\346\230\212/20230306 \345\255\220\346\237\245\350\257\242.md" "b/45 \346\226\275\346\210\220\346\230\212/20230306 \345\255\220\346\237\245\350\257\242.md" new file mode 100644 index 0000000..ea74a20 --- /dev/null +++ "b/45 \346\226\275\346\210\220\346\230\212/20230306 \345\255\220\346\237\245\350\257\242.md" @@ -0,0 +1,150 @@ +| | | | +| ---- | ------------------------------------------------------------ | :----------------------------------------------------------- | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | | | +| | [32](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_32) | # 1、作业 | +| | [33](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_33) | | +| | [34](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_34) | ```sql | +| | [35](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_35) | use mockq; | +| | [36](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_36) | **create** **table** stuinfo( | +| | [37](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_37) | stuno varchar(10), | +| | [38](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_38) | stuname varchar(5), | +| | [39](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_39) | stusex enum('男','女'), | +| | [40](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_40) | stuage varchar(5), | +| | [41](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_41) | stuaddress varchar(10), | +| | [42](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_42) | stuseat int | +| | [43](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_43) | ); | +| | [44](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_44) | **create** **table** stuexam( | +| | [45](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_45) | examno int, | +| | [46](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_46) | stuno varchar(10), | +| | [47](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_47) | whitenexam varchar(5), | +| | [48](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_48) | labexam varchar(5) | +| | [49](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_49) | ); | +| | [50](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_50) | **create** **table** stumarks( | +| | [51](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_51) | examno int, | +| | [52](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_52) | stuid varchar(10), | +| | [53](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_53) | score varchar(5) | +| | [54](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_54) | ); | +| | [55](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_55) | **insert** **into** stuinfo **values** | +| | [56](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_56) | ('s2501','张秋利','男','20','美国硅谷',1), | +| | [57](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_57) | ('s2502','李斯文','女','18','湖北武汉',2), | +| | [58](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_58) | ('s2503','马文才','男','18','湖南长沙',3), | +| | [59](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_59) | ('s2504','欧阳俊雄','女','21','湖北武汉',4), | +| | [60](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_60) | ('s2505','梅超风','男','20','湖北武汉',5), | +| | [61](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_61) | ('s2506','陈旋风','男','19','美国硅谷',6); | +| | [62](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_62) | **insert** **into** stuexam **VALUES** | +| | [63](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_63) | (1,'s2501','50','70'), | +| | [64](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_64) | (2,'s2502','60','65'), | +| | [65](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_65) | (3,'s2503','86','70'), | +| | [66](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_66) | (4,'s2504','40','80'), | +| | [67](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_67) | (5,'s2505','70','85'), | +| | [68](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_68) | (6,'s2506','85','90'); | +| | [69](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_69) | **insert** **into** stumarks **VALUES** | +| | [70](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_70) | (1,'s2501','88'), | +| | [71](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_71) | (2,'s2501','92'), | +| | [72](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_72) | (3,'s2501','53'), | +| | [73](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_73) | (4,'s2502','60'), | +| | [74](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_74) | (5,'s2502','99'), | +| | [75](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_75) | (6,'s2503','82'); | +| | [76](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_76) | -- 在如图的数据表上完成以下题目 | +| | [77](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_77) | -- | +| | [78](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_78) | -- 1.查询出年龄比班上平均年龄大的学生的信息 | +| | [79](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_79) | **select** * **from** stuinfo **where** stuage > (**select** **avg**(stuage) **from** stuinfo); | +| | [80](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_80) | -- 2.查询出每个学生的学号，姓名，性别和选修课程的最高分（stuMarks） | +| | [81](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_81) | -- select a.stuno,a.stuname,a.stusex,max(b.score) | +| | [82](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_82) | -- from stuinfo as a left join stumarks as b on a.stuno = b.stuid group by a.stuno; | +| | [83](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_83) | **select** b.stuno,b.stuname,b.stusex,**max**(a.score) **from** stumarks **as** a **right** **join** stuinfo **as** b **on** a.stuid = b.stuno **group** **by** b.stuno; | +| | [84](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_84) | -- 3.查询出每个学生的学号，姓名，性别和考试平均分（stuExam） | +| | [85](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_85) | **select** a.stuno,a.stuname,a.stusex,(b.whitenexam + b.labexam)/2 **as** '考试平均分' **from** stuinfo **as** a **left** **join** stuexam **as** b **on** a.stuno = b.stuno **group** **by** a.stuno; | +| | [86](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_86) | -- 4.查询性别是男并且年龄大于等于20的学生的信息(用两种方法实现：普通查询和子查询) | +| | [87](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_87) | **select** * **from** stuinfo **where** stusex = '男' **and** stuage >= 20; | +| | [88](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_88) | **select** stuinfo.* **from** stuinfo **right** **join** | +| | [89](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_89) | (**select** * **from** stuinfo **where** stuage >= 20) **as** age **on** stuinfo.stuno = age.stuno **where** age.stusex = '男'; | +| | [90](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_90) | -- 5.查询出年龄比所有男生年龄都大的女生的信息 | +| | [91](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_91) | | +| | [92](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_92) | **select** * **from** stuinfo **where** stuage > (**select** **max**(stuage) **from** stuinfo **where** stusex = '男') **and** stusex = '女'; | +| | [93](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_93) | -- 6.查询出所有选修课程都及格的学生的信息 （stuMarks） | +| | [94](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_94) | -- select * from stumarks where score > 60 and | +| | [95](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_95) | **SELECT** * | +| | [96](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_96) | **from** stuinfo **as** a **inner** **join** stumarks **as** b **on** a.stuno = b.stuid **where** score > 60 ; | +| | [97](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_97) | -- 7.查询出参加考试的学生的信息（用表连接，in二种方法做）（stuMarks） | +| | [98](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_98) | **select** * **from** stuinfo **as** a **right** **join** stumarks **as** b **on** a.stuno = b.stuid; | +| | [99](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_99) | **select** * **from** stuinfo **where** stuno **in** (**select** stuno **from** stuinfo **as** a **right** **join** stumarks **as** b **on** a.stuno = b.stuid); | +| | [100](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_100) | -- 8.查询出没有参加考试的学生的信息（用表连接，in二种方法做）（stuMarks） | +| | [101](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_101) | **select** * **from** stuinfo **as** a **left** **join** stumarks **as** b **on** a.stuno = b.stuid **where** b.stuid **is** **null**; | +| | [102](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_102) | **select** * **from** stuinfo **where** stuno **not** **in** (**select** stuno **from** stuinfo **as** a **right** **join** stumarks **as** b **on** a.stuno = b.stuid); | +| | [103](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_103) | -- 9.将有一门成绩成绩大于90分的学生的基本信息查询出来（stuMarks） | +| | [104](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_104) | **select** * **from** stumarks **where** score > 90; | +| | [105](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_105) | **select** * **from** stuinfo **as** a **inner** **join** (**select** * **from** stumarks **where** score > 90) **as** b **on** a.stuno = b.stuid; | +| | [106](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_106) | -- 10.查询出平均成绩在80分以上的学生的基本信息（stuMarks） | +| | [107](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_107) | **select** **avg**(score) **from** stumarks **group** **by** stuid **having** **avg**(score) > 80; | +| | [108](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_108) | **select** stuinfo.* | +| | [109](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_109) | **from** (**select** stuid,**avg**(score) **from** stumarks **group** **by** stuid **having** **avg**(score) > 80) **as** a **inner** **join** stuinfo **on** a.stuid = stuinfo.stuno; | +| | [110](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_110) | -- 11.查询出某同学所有考试成绩比“张秋利”同学所有分数都高的学生基本信息（stuMarks） | +| | [111](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_111) | **select** **max**(score) **from** stumarks **where** stuid = (**select** stuno **from** stuinfo **where** stuname = '张秋利'); | +| | [112](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_112) | **select** a.* | +| | [113](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_113) | **from** stuinfo **as** a **inner** **join** stumarks **as** b **on** a.stuno = b.stuid **where** b.score > (**select** **max**(score) **from** stumarks **where** stuid = (**select** stuno **from** stuinfo **where** stuname = '张秋利')); | +| | [114](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_114) | -- 12.查询出某同学所有考试成绩只需要比“张秋利”同学某个分数高的学生基本信息（stuMarks） | +| | [115](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_115) | **select** **min**(score) **from** stumarks **where** stuid = (**select** stuno **from** stuinfo **where** stuname = '张秋利'); | +| | [116](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_116) | **select** a.* | +| | [117](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_117) | **from** stuinfo **as** a **inner** **join** stumarks **as** b **on** a.stuno = b.stuid **where** b.score > (**select** **min**(score) **from** stumarks **where** stuid = (**select** stuno **from** stuinfo **where** stuname = '张秋利')) **group** **by** a.stuno; | +| | [118](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_118) | -- 13.查询班上比所有男生年龄都要大的女生的信息 | +| | [119](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_119) | **select** * **from** stuinfo **where** stuage > (**select** **max**(stuage) **from** stuinfo **where** stusex = '男') **and** stusex = '女'; | +| | [120](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_120) | -- 14.查询出只是比某个男生年龄大的女生的信息 | +| | [121](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_121) | **select** * **from** stuinfo **where** stuage > (**select** **min**(stuage) **from** stuinfo **where** stusex = '男') **and** stusex = '女'; | +| | [122](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_122) | # 2、笔记 | + +| sql | +| :--- | ------------------------------------------------------------ | ------------------------------------------------------------ | +| | [4](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_4) | 子查询 | +| | [5](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_5) | -- 嵌套在其它SQL语句中的select语句 | +| | [6](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_6) | -- 子查询通常在外层语句之前优先执行，所以要用（）包括起来 | +| | [7](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_7) | -- 子查询的结果，一般作为外层语句的条件，数据源等 | +| | [8](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_8) | -- 形式一,select后面嵌套子查询 | +| | [9](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_9) | **select** (子查询) **from** 表名 [**where**/**having** 条件]; | +| | [10](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_10) | -- 形式二，在where/having 后面做条件 | +| | [11](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_11) | **select** 字段名 **from** 表名 **where**/**having** (子查询); | +| | [12](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_12) | | +| | [13](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_13) | -- 当子查询放在where 、 having 后面当条件用时： | +| | [14](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_14) | -- 单列单个值，可以直接用>,<,<=...!=，这些比较运算符 | +| | [15](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_15) | -- 单列多个值，要用in,not in 这种集合的比较 | +| | [16](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_16) | -- 单列多个值，可以用>,<,<=...!=，比较运算符，搭配any,all 这些关键字，一起使用 | +| | [17](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_17) | | +| | [18](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_18) | | +| | [19](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_19) | | +| | [20](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_20) | -- 形式三，在from后面,形成一个临时表，必须加一个别名 | +| | [21](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_21) | **select** 字段名 **from** (子查询) [**as**] 别名 [**where**/**having** 条件]; | +| | [22](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_22) | | +| | [23](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_23) | | +| | [24](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_24) | -- 子查询的结果： | +| | [25](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_25) | -- 单列单个值：可以放在select 后，也可以放where/having之后 | +| | [26](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_26) | -- 单列多个值：where后，或having后 ，不用直接用<,=,>= 这种单纯的比较运算符。但可以用搭配any(任意一个),all(所有的)等关键字--- 一起使用。还可以用in,not in这种表达式 | +| | [27](https://gitee.com/class-04-grade-2022/mysql-base/pulls/195/files#f5310d6192212707d153d2926890c7f035b2147e_0_27) | -- 多列时，只能当临时表来表用，放在from后面，而且必须，给他取个别名 | \ No newline at end of file -- Gitee