1创建2个表student与score表,要求student表有id,createDate,userName,phone,age,sex,introduce,
要求score表有id,scoreName,result,studentId(student表的id外键)。
要求student表中插入5条学生信息,都要是中文的。
要求score表中对应studentId插入10条信息,每个学生ID要有2个科目的成绩。
给出DDL与DML语句。
-- 创建student表
CREATE TABLE student (
id INT PRIMARY KEY AUTO_INCREMENT,
createDate DATE NOT NULL,
userName VARCHAR(50) NOT NULL,
phone VARCHAR(20) NOT NULL,
age INT NOT NULL,
sex ENUM('男', '女') NOT NULL,
introduce TEXT
);
-- 创建score表
CREATE TABLE score (
id INT PRIMARY KEY AUTO_INCREMENT,
scoreName VARCHAR(50) NOT NULL,
result DECIMAL(5, 2) NOT NULL,
studentId INT,
FOREIGN KEY (studentId) REFERENCES student(id) ON DELETE CASCADE
);
2、帮我创建一个多表联合查询以student为主表,查看学生的所有科目成绩总分。
SELECT
s.id AS student_id,
s.userName,
s.phone,
s.age,
s.sex,
s.introduce,
SUM(sc.result) AS total_score
FROM
student s
LEFT JOIN
score sc ON s.id = sc.studentId
GROUP BY
s.id, s.userName, s.phone, s.age, s.sex, s.introduce;
3、帮我根据两个DDL创建一个插入信息的存储过程,先插入10条学生表信息,再根据插入的学生表信息插入100条对应studentId的score成绩,
所有信息随机生成,学生表的自增序号从6开始。
DELIMITER //
CREATE PROCEDURE InsertStudentsAndScores()
BEGIN
DECLARE v_student_id INT;
DECLARE v_counter INT DEFAULT 0;
-- 设置AUTO_INCREMENT起始值为6
ALTER TABLE student AUTO_INCREMENT = 6;
-- 插入10条学生信息
WHILE v_counter < 10 DO
SET @createDate = CURDATE() - INTERVAL FLOOR(RAND() * 365) DAY; -- 随机日期
SET @userName = CONCAT('Student', FLOOR(RAND() * 1000)); -- 随机用户名
SET @phone = CONCAT('1', LPAD(FLOOR(RAND() * 100000000), 9, '0')); -- 随机电话号码
SET @age = FLOOR(18 + (RAND() * 10)); -- 随机年龄,范围18-28
SET @sex = IF(RAND() > 0.5, '男', '女'); -- 随机性别
SET @introduce = CONCAT('This is a random introduction for ', @userName); -- 随机介绍
-- 插入学生信息
INSERT INTO student (createDate, userName, phone, age, sex, introduce)
VALUES (@createDate, @userName, @phone, @age, @sex, @introduce);
-- 获取新插入学生的ID
SELECT LAST_INSERT_ID() INTO v_student_id;
-- 插入10条成绩信息
REPEAT
SET @scoreName = CONCAT('Subject', FLOOR(RAND() * 10)); -- 随机科目名
SET @result = FLOOR(60 + (RAND() * 40)); -- 随机成绩,范围60-100
-- 插入成绩信息
INSERT INTO score (scoreName, result, studentId)
VALUES (@scoreName, @result, v_student_id);
SET v_counter = v_counter + 1;
UNTIL v_counter >= 100 END REPEAT; -- 这里应该是固定的10次循环,因为我们要为每个学生插入10条成绩
SET v_counter = 0; -- 重置计数器以继续插入下一个学生的成绩
END WHILE;
END //
DELIMITER ;
DELIMITER //
CREATE PROCEDURE InsertStudentsAndScores()
BEGIN
DECLARE v_student_id INT;
DECLARE v_counter INT DEFAULT 0;
-- 设置AUTO_INCREMENT起始值为6
ALTER TABLE student AUTO_INCREMENT = 6;
-- 插入10条学生信息
WHILE v_counter < 10 DO
SET @createDate = CURDATE() - INTERVAL FLOOR(RAND() * 365) DAY;
SET @userName = CONCAT('Student', FLOOR(RAND() * 1000));
SET @phone = CONCAT('1', LPAD(FLOOR(RAND() * 100000000), 9, '0'));
SET @age = FLOOR(18 + (RAND() * 10));
SET @sex = IF(RAND() > 0.5, '男', '女');
SET @introduce = CONCAT('This is a random introduction for ', @userName);
-- 插入学生信息
INSERT INTO student (createDate, userName, phone, age, sex, introduce)
VALUES (@createDate, @userName, @phone, @age, @sex, @introduce);
-- 获取新插入学生的ID
SELECT LAST_INSERT_ID() INTO v_student_id;
-- 为当前学生插入10条成绩信息
DECLARE v_score_counter INT DEFAULT 0;
WHILE v_score_counter < 10
4、帮我创建一个修改score表scoreName的触发器,当修改scoreName的时候触发,判断修改的scoreName是否是数学,如果是数学就改成(天书)。
并且给出测试示例。
DELIMITER //
CREATE TRIGGER trg_update_scoreName
BEFORE UPDATE ON score
FOR EACH ROW
BEGIN
IF NEW.scoreName = '数学' THEN
SET NEW.scoreName = '天书';
END IF;
END;
//
DELIMITER ;
-- 插入学生数据
INSERT INTO student (createDate, userName, phone, age, sex, introduce) VALUES
('2023-01-01', '张三', '13800138000', 20, '男', '张三是一个热爱学习的学生。');
-- 插入成绩数据
INSERT INTO score (scoreName, result, studentId) VALUES
('数学', 90.50, 1),
('语文', 85.25, 1);
5、创建一个两个表的综合【游标查询】,要求根据学生姓名进行查询,查询的结果返回两个表的综合信息。
DELIMITER //
CREATE PROCEDURE GetStudentScoresByName(IN p_userName VARCHAR(50))
BEGIN
-- 声明变量来存储从游标中获取的数据
DECLARE done INT DEFAULT FALSE;
DECLARE v_student_id INT;
DECLARE v_createDate DATE;
DECLARE v_userName VARCHAR(50);
DECLARE v_phone VARCHAR(20);
DECLARE v_age INT;
DECLARE v_sex ENUM('男', '女');
DECLARE v_introduce TEXT;
DECLARE v_score_id INT;
DECLARE v_scoreName VARCHAR(50);
DECLARE v_result DECIMAL(5, 2);
-- 声明游标
DECLARE cur CURSOR FOR
SELECT
s.id, s.createDate, s.userName, s.phone, s.age, s.sex, s.introduce,
sc.id AS score_id, sc.scoreName, sc.result
FROM
student s
JOIN
score sc ON s.id = sc.studentId
WHERE
s.userName = p_userName;
-- 声明游标结束时的处理
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
-- 打开游标
OPEN cur;
-- 读取游标中的数据
read_loop: LOOP
FETCH cur INTO v_student_id, v_createDate, v_userName, v_phone, v_age, v_sex, v_introduce,
v_score_id, v_scoreName, v_result;
IF done THEN
LEAVE read_loop;
END IF;
-- 这里你可以做你需要的处理,比如输出数据或者将其插入到其他表中
-- 这里我们只是简单地输出数据
SELECT v_student_id, v_createDate, v_userName, v_phone, v_age, v_sex, v_introduce,
v_score_id, v_scoreName, v_result;
END LOOP;
-- 关闭游标
CLOSE cur;
END //
DELIMITER ;
CALL GetStudentScoresByName('张三');
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