前置 sql 語句
用來建立表、插入數據sql
SET NAMES utf8mb4; SET FOREIGN_KEY_CHECKS = 0; -- ---------------------------- -- Table structure for course -- ---------------------------- DROP TABLE IF EXISTS `course`; CREATE TABLE `course` ( `Cno` int(11) NOT NULL COMMENT '課程編號', `Cname` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '課程名稱', `Tno` int(11) NULL DEFAULT NULL COMMENT '老師編號', PRIMARY KEY (`Cno`) USING BTREE ) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Compact; -- ---------------------------- -- Records of course -- ---------------------------- INSERT INTO `course` VALUES (1, '數學', 1); INSERT INTO `course` VALUES (2, '語文', 2); INSERT INTO `course` VALUES (3, '英文', 1); -- ---------------------------- -- Table structure for sc -- ---------------------------- DROP TABLE IF EXISTS `sc`; CREATE TABLE `sc` ( `Sno` int(11) NOT NULL COMMENT '學號', `Cno` int(11) NOT NULL COMMENT '課程編號', `score` int(255) NULL DEFAULT NULL COMMENT '分數', PRIMARY KEY (`Sno`, `Cno`) USING BTREE ) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Compact; -- ---------------------------- -- Records of sc -- ---------------------------- INSERT INTO `sc` VALUES (1, 1, 99); INSERT INTO `sc` VALUES (1, 2, 80); INSERT INTO `sc` VALUES (1, 3, 50); INSERT INTO `sc` VALUES (2, 1, 70); INSERT INTO `sc` VALUES (2, 2, 90); INSERT INTO `sc` VALUES (3, 1, 90); INSERT INTO `sc` VALUES (4, 1, 60); INSERT INTO `sc` VALUES (4, 2, 50); INSERT INTO `sc` VALUES (4, 3, 40); -- ---------------------------- -- Table structure for student -- ---------------------------- DROP TABLE IF EXISTS `student`; CREATE TABLE `student` ( `Sno` int(255) NOT NULL COMMENT '學號', `Sname` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '姓名', `Sage` int(255) NULL DEFAULT NULL COMMENT '年齡', `Ssex` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '性別', PRIMARY KEY (`Sno`) USING BTREE ) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Compact; -- ---------------------------- -- Records of student -- ---------------------------- INSERT INTO `student` VALUES (1, '張三丰', 108, '男'); INSERT INTO `student` VALUES (2, '李小龍', 20, '男'); INSERT INTO `student` VALUES (3, '小龍女', 17, '女'); INSERT INTO `student` VALUES (4, '白髮魔女', 18, '女'); INSERT INTO `student` VALUES (5, '韋小寶', 19, '男'); -- ---------------------------- -- Table structure for teacher -- ---------------------------- DROP TABLE IF EXISTS `teacher`; CREATE TABLE `teacher` ( `Tno` int(11) NOT NULL COMMENT '老師編號', `Tname` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '老師名稱', PRIMARY KEY (`Tno`) USING BTREE ) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Compact; -- ---------------------------- -- Records of teacher -- ---------------------------- INSERT INTO `teacher` VALUES (1, '無崖子'); INSERT INTO `teacher` VALUES (2, '孤獨求敗'); INSERT INTO `teacher` VALUES (3, '洪七公'); SET FOREIGN_KEY_CHECKS = 1;
題目列表
一、查詢年齡小於18歲的學員信息 spa
二、查詢無崖子授課信息.net
三、查詢沒有參與任意課程的學生信息code
四、查詢無崖子每一個授課課程的學員人數 統計 + 分組 blog
五、查詢張三丰數學成績ci
六、查詢出語文最高分【待完成】get
七、查詢沒有參與語文考試的學生信息數學
八、查詢語數外三門成績的平均分class
九、查詢報名孤獨求敗老師課程的學生信息select
十、沒有報名孤獨求敗老師課程的學生信息
答案列表
#1 查詢年齡小於18歲的學員信息
select * from student where Sage<18; #2 查詢無崖子授課信息 select * from teacher t join course c on c.Tno = t.Tno where t.Tname="無崖子"; #3 查詢沒有參與任意課程的學生信息 select * from student s left join sc on s.Sno = sc.Sno where sc.score is null; #4 查詢無崖子每一個授課課程的學員人數 統計 + 分組 select t.Tname,c.Cname,count(1) as "學員人數" from teacher t join course c on t.Tno = c.Tno join sc on sc.Cno = c.Cno group by sc.Cno HAVING t.Tname="無崖子"; #5 查詢張三丰數學成績 select s.Sname,c.Cname,sc.score from student s join sc on s.Sno = sc.Sno join course c on c.Cno = sc.Cno where s.Sname="張三丰" and c.Cname="數學"; #6 查詢出語文最高分【待完成】 select s.Sname,max(sc.score) as "分數" from sc join course c on sc.Cno = c.Cno join student s on s.Sno = sc.Sno where c.Cname="語文"; #7 查詢沒有參與語文考試的學生信息 select * from student s join sc on sc.Sno = s.Sno right join course c on c.Cno = sc.Cno and c.Cname = "語文" and sc.score is null; select * from course c join sc on c.Cno = sc.Cno and c.Cname="語文" right join student s on s.Sno = sc.Sno where sc.score is null; #8 查詢語數外三門成績的平均分 select c.Cname,avg(sc.score) from course c join sc on c.Cno = sc.Cno GROUP BY c.Cno; #9 查詢報名孤獨求敗老師課程的學生信息 select * from student s join sc on sc.Sno = s.Sno join course c on c.Cno= sc.Cno join teacher t on t.Tno = c.Tno where t.Tname="孤獨求敗" ; select * from teacher t join course c on c.Tno = t.Tno and t.Tname = "孤獨求敗" join sc on c.Cno = sc.Cno right join student s on s.Sno = sc.Sno where sc.score is not null; #10 沒有報名孤獨求敗老師課程的學生信息 select * from teacher t join course c on c.Tno = t.Tno and t.Tname = "孤獨求敗" join sc on c.Cno = sc.Cno right join student s on s.Sno = sc.Sno where sc.score is null;
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