diff --git "a/06 \346\236\227\346\231\237\350\276\211/ 0904/.keep" "b/06 \346\236\227\346\231\237\350\276\211/ 0904/.keep"
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git "a/06 \346\236\227\346\231\237\350\276\211/ 0904/0904.MD" "b/06 \346\236\227\346\231\237\350\276\211/ 0904/0904.MD"
new file mode 100644
index 0000000000000000000000000000000000000000..5494fdd207790ea1278336c91c19c1b45d222385
--- /dev/null
+++ "b/06 \346\236\227\346\231\237\350\276\211/ 0904/0904.MD"	
@@ -0,0 +1,6 @@
+# 心得
+
+```text
+今天学会了VIP解析，以及多个的学习的好网站（绝对没有去抄答案的想法，信我是秦始皇）
+```
+
diff --git "a/06 \346\236\227\346\231\237\350\276\211/.keep" "b/06 \346\236\227\346\231\237\350\276\211/.keep"
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git "a/06 \346\236\227\346\231\237\350\276\211/0905/.keep" "b/06 \346\236\227\346\231\237\350\276\211/0905/.keep"
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git "a/06 \346\236\227\346\231\237\350\276\211/0905/0905.md" "b/06 \346\236\227\346\231\237\350\276\211/0905/0905.md"
new file mode 100644
index 0000000000000000000000000000000000000000..9e5e6ff41dc1c6dad3526dc85c36d3ae05c83fdc
--- /dev/null
+++ "b/06 \346\236\227\346\231\237\350\276\211/0905/0905.md"	
@@ -0,0 +1,261 @@
+# 心得
+
+```text
+在多表多属性的数据库中，表中的元素关系类别
+一对一：一个人对一个身份证，相互独立且唯一		联表时将一个表的主键放到另一个表做外键
+一对多：一个教室对多个人					联表时可以要将一的表中的主键放在多的表做外键
+多对多：学生对各个科的成绩					联表时需要第三个表来联系两个表的主键
+使用E-R图表来表明各个表的联系
+```
+
+# 代码
+
+```mysql
+SET NAMES utf8mb4;
+SET FOREIGN_KEY_CHECKS = 0;
+
+-- Table structure for class
+
+DROP TABLE IF EXISTS `class`;
+CREATE TABLE `class`  (
+  `cid` int(11) NOT NULL AUTO_INCREMENT,
+  `cName` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
+  `sid` int(11) NULL DEFAULT NULL,
+  `cr_id` int(11) NULL DEFAULT NULL,
+  PRIMARY KEY (`cid`) USING BTREE,
+  INDEX `sid`(`sid`) USING BTREE,
+  INDEX `cr_id`(`cr_id`) USING BTREE,
+  CONSTRAINT `class_ibfk_1` FOREIGN KEY (`sid`) REFERENCES `major` (`sid`) ON DELETE RESTRICT ON UPDATE RESTRICT,
+  CONSTRAINT `class_ibfk_2` FOREIGN KEY (`cr_id`) REFERENCES `classroom` (`cr_id`) ON DELETE RESTRICT ON UPDATE RESTRICT
+) ENGINE = InnoDB AUTO_INCREMENT = 7 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = DYNAMIC;
+
+-- Records of class
+
+-- ----------------------------
+
+INSERT INTO `class` VALUES (1, '一班', 1, 1);
+INSERT INTO `class` VALUES (2, '二班', 1, 2);
+INSERT INTO `class` VALUES (3, '三班', 2, 3);
+INSERT INTO `class` VALUES (4, '四班', 2, 4);
+INSERT INTO `class` VALUES (5, '五班', 3, 1);
+INSERT INTO `class` VALUES (6, '六班', 3, 2);
+
+-- ----------------------------
+
+-- Table structure for classroom
+
+-- ----------------------------
+
+DROP TABLE IF EXISTS `classroom`;
+CREATE TABLE `classroom`  (
+  `cr_id` int(11) NOT NULL AUTO_INCREMENT,
+  `address` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
+  PRIMARY KEY (`cr_id`) USING BTREE
+) ENGINE = InnoDB AUTO_INCREMENT = 5 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = DYNAMIC;
+
+-- ----------------------------
+
+-- Records of classroom
+
+-- ----------------------------
+
+INSERT INTO `classroom` VALUES (1, '教室101');
+INSERT INTO `classroom` VALUES (2, '教室102');
+INSERT INTO `classroom` VALUES (3, '教室103');
+INSERT INTO `classroom` VALUES (4, '教室104');
+
+-- ----------------------------
+
+-- Table structure for course
+
+-- ----------------------------
+
+DROP TABLE IF EXISTS `course`;
+CREATE TABLE `course`  (
+  `cou_id` int(11) NOT NULL AUTO_INCREMENT,
+  `name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
+  PRIMARY KEY (`cou_id`) USING BTREE
+) ENGINE = InnoDB AUTO_INCREMENT = 5 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = DYNAMIC;
+
+-- ----------------------------
+
+-- Records of course
+
+-- ----------------------------
+
+INSERT INTO `course` VALUES (1, '语文');
+INSERT INTO `course` VALUES (2, '数学');
+INSERT INTO `course` VALUES (3, '英语');
+INSERT INTO `course` VALUES (4, '计算机');
+
+-- ----------------------------
+
+-- Table structure for coursetable
+
+-- ----------------------------
+
+DROP TABLE IF EXISTS `coursetable`;
+CREATE TABLE `coursetable`  (
+  `ct_id` int(11) NOT NULL AUTO_INCREMENT,
+  `name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
+  `cr_id` int(11) NULL DEFAULT NULL,
+  PRIMARY KEY (`ct_id`) USING BTREE,
+  INDEX `cr_id`(`cr_id`) USING BTREE,
+  CONSTRAINT `coursetable_ibfk_1` FOREIGN KEY (`cr_id`) REFERENCES `classroom` (`cr_id`) ON DELETE RESTRICT ON UPDATE RESTRICT
+) ENGINE = InnoDB AUTO_INCREMENT = 5 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = DYNAMIC;
+
+-- ----------------------------
+
+-- Records of coursetable
+
+-- ----------------------------
+
+INSERT INTO `coursetable` VALUES (1, '语文', 1);
+INSERT INTO `coursetable` VALUES (2, '数学', 2);
+INSERT INTO `coursetable` VALUES (3, '英语', 3);
+INSERT INTO `coursetable` VALUES (4, '计算机', 4);
+
+-- ----------------------------
+
+-- Table structure for department
+
+-- ----------------------------
+
+DROP TABLE IF EXISTS `department`;
+CREATE TABLE `department`  (
+  `did` int(11) NOT NULL AUTO_INCREMENT,
+  `dName` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
+  PRIMARY KEY (`did`) USING BTREE
+) ENGINE = InnoDB AUTO_INCREMENT = 2 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = DYNAMIC;
+
+-- ----------------------------
+
+-- Records of department
+
+-- ----------------------------
+
+INSERT INTO `department` VALUES (1, '软件工程学院');
+
+-- ----------------------------
+
+-- Table structure for major
+
+-- ----------------------------
+
+DROP TABLE IF EXISTS `major`;
+CREATE TABLE `major`  (
+  `sid` int(11) NOT NULL AUTO_INCREMENT,
+  `sName` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
+  `did` int(11) NOT NULL,
+  PRIMARY KEY (`sid`) USING BTREE,
+  INDEX `did`(`did`) USING BTREE,
+  CONSTRAINT `major_ibfk_1` FOREIGN KEY (`did`) REFERENCES `department` (`did`) ON DELETE RESTRICT ON UPDATE RESTRICT
+) ENGINE = InnoDB AUTO_INCREMENT = 4 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = DYNAMIC;
+
+-- ----------------------------
+
+-- Records of major
+
+-- ----------------------------
+
+INSERT INTO `major` VALUES (1, '前端', 1);
+INSERT INTO `major` VALUES (2, '后端', 1);
+INSERT INTO `major` VALUES (3, '新媒体', 1);
+
+-- ----------------------------
+
+-- Table structure for selectcourse
+
+-- ----------------------------
+
+DROP TABLE IF EXISTS `selectcourse`;
+CREATE TABLE `selectcourse`  (
+  `se_id` int(11) NOT NULL AUTO_INCREMENT,
+  `stu_id` int(11) NULL DEFAULT NULL,
+  `cou_id` int(11) NULL DEFAULT NULL,
+  PRIMARY KEY (`se_id`) USING BTREE,
+  INDEX `stu_id`(`stu_id`) USING BTREE,
+  INDEX `cou_id`(`cou_id`) USING BTREE,
+  CONSTRAINT `selectcourse_ibfk_1` FOREIGN KEY (`stu_id`) REFERENCES `student` (`stu_id`) ON DELETE RESTRICT ON UPDATE RESTRICT,
+  CONSTRAINT `selectcourse_ibfk_2` FOREIGN KEY (`cou_id`) REFERENCES `course` (`cou_id`) ON DELETE RESTRICT ON UPDATE RESTRICT
+) ENGINE = InnoDB AUTO_INCREMENT = 7 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = DYNAMIC;
+
+-- ----------------------------
+
+-- Records of selectcourse
+
+-- ----------------------------
+
+INSERT INTO `selectcourse` VALUES (1, 1, 1);
+INSERT INTO `selectcourse` VALUES (2, 2, 2);
+INSERT INTO `selectcourse` VALUES (3, 3, 3);
+INSERT INTO `selectcourse` VALUES (4, 4, 4);
+INSERT INTO `selectcourse` VALUES (5, 5, 1);
+INSERT INTO `selectcourse` VALUES (6, 6, 2);
+
+-- ----------------------------
+
+-- Table structure for student
+
+-- ----------------------------
+
+DROP TABLE IF EXISTS `student`;
+CREATE TABLE `student`  (
+  `stu_id` int(11) NOT NULL AUTO_INCREMENT,
+  `id` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
+  `name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
+  `cid` int(11) NULL DEFAULT NULL,
+  PRIMARY KEY (`stu_id`) USING BTREE,
+  INDEX `cid`(`cid`) USING BTREE,
+  CONSTRAINT `student_ibfk_1` FOREIGN KEY (`cid`) REFERENCES `class` (`cid`) ON DELETE RESTRICT ON UPDATE RESTRICT
+) ENGINE = InnoDB AUTO_INCREMENT = 7 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = DYNAMIC;
+
+-- ----------------------------
+
+-- Records of student
+
+-- ----------------------------
+
+INSERT INTO `student` VALUES (1, '1', '梦泪', 1);
+INSERT INTO `student` VALUES (2, '2', '蜗壳', 2);
+INSERT INTO `student` VALUES (3, '3', '杰鸽', 3);
+INSERT INTO `student` VALUES (4, '4', '王毛毛', 4);
+INSERT INTO `student` VALUES (5, '5', '郑绿灰', 5);
+INSERT INTO `student` VALUES (6, '6', '郑蓝黑', 6);
+
+-- ----------------------------
+
+-- Table structure for teacher
+
+-- ----------------------------
+
+DROP TABLE IF EXISTS `teacher`;
+CREATE TABLE `teacher`  (
+  `tid` int(11) NOT NULL AUTO_INCREMENT,
+  `name` varchar(11) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
+  `cou_id` int(11) NULL DEFAULT NULL,
+  PRIMARY KEY (`tid`) USING BTREE,
+  INDEX `cou_id`(`cou_id`) USING BTREE,
+  CONSTRAINT `teacher_ibfk_1` FOREIGN KEY (`cou_id`) REFERENCES `course` (`cou_id`) ON DELETE RESTRICT ON UPDATE RESTRICT
+) ENGINE = InnoDB AUTO_INCREMENT = 5 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = DYNAMIC;
+
+-- ----------------------------
+
+-- Records of teacher
+
+-- ----------------------------
+
+INSERT INTO `teacher` VALUES (1, '郑弘辉', 1);
+INSERT INTO `teacher` VALUES (2, '陈姐', 2);
+INSERT INTO `teacher` VALUES (3, '张飞', 3);
+INSERT INTO `teacher` VALUES (4, '林吮吸', 4);
+
+SET FOREIGN_KEY_CHECKS = 1;
+```
+
+# 查询
+
+```MySQL
+SELECT student.`name` as '学生姓名',course.`name` as '课程名' FROM student,selectcourse,course where student.stu_id=selectcourse.stu_id and selectcourse.cou_id=course.cou_id and student.`name`='蜗壳';
+```
+
diff --git "a/06 \346\236\227\346\231\237\350\276\211/0905/\347\273\230\345\233\2762.vsdx" "b/06 \346\236\227\346\231\237\350\276\211/0905/\347\273\230\345\233\2762.vsdx"
new file mode 100644
index 0000000000000000000000000000000000000000..a32a0705242054397c2294c1486b71e17a3fd1cd
Binary files /dev/null and "b/06 \346\236\227\346\231\237\350\276\211/0905/\347\273\230\345\233\2762.vsdx" differ