sql5个问题 - 技术栈

问题1：

帮我创建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。

sql 复制代码

-- 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 INT NOT NULL,
    studentId INT,
    FOREIGN KEY (studentId) REFERENCES student(id) ON DELETE CASCADE
);

-- 插入5条学生信息
INSERT INTO student (createDate, userName, phone, age, sex, introduce) VALUES
('2023-01-01', '张三', '13800138000', 20, '男', '来自北方，喜欢运动'),
('2023-02-02', '李四', '13900139000', 21, '女', '来自南方，爱好音乐'),
('2023-03-03', '王五', '13700137000', 22, '男', '来自东部，擅长编程'),
('2023-04-04', '赵六', '13600136000', 23, '女', '来自西部，喜欢旅行'),
('2023-05-05', '孙七', '13500135000', 24, '男', '来自中部，热爱阅读');

-- 插入10条成绩信息
INSERT INTO score (scoreName, result, studentId) VALUES
('数学', 90, (SELECT id FROM student WHERE userName = '张三')),
('语文', 85, (SELECT id FROM student WHERE userName = '张三')),
('数学', 88, (SELECT id FROM student WHERE userName = '李四')),
('英语', 92, (SELECT id FROM student WHERE userName = '李四')),
('物理', 89, (SELECT id FROM student WHERE userName = '王五')),
('化学', 93, (SELECT id FROM student WHERE userName = '王五')),
('数学', 86, (SELECT id FROM student WHERE userName = '赵六')),
('生物', 91, (SELECT id FROM student WHERE userName = '赵六')),
('历史', 87, (SELECT id FROM student WHERE userName = '孙七')),
('地理', 94, (SELECT id FROM student WHERE userName = '孙七'));

问题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。

sql 复制代码

SELECT 
    s.id AS student_id,
    s.userName AS student_name,
    SUM(sc.result) AS '总分',
    AVG(sc.result) AS '平均分'
 FROM 
    student s	
LEFT JOIN 
    score sc ON s.id = sc.studentId
GROUP BY 
    s.id, s.userName
		having AVG(sc.result)>85
		order by AVG(sc.result)>85 desc;

问题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。不要使用DECLARE声明变量，要使用set生明。

sql 复制代码

DELIMITER //

CREATE PROCEDURE InsertRandomStudentAndScoreData()
BEGIN
    -- 插入10条学生信息
    REPEAT
        INSERT INTO student (createDate, userName, phone, age, sex, introduce)
        VALUES (
            CURDATE() - INTERVAL FLOOR(RAND() * 30) DAY, -- 随机生成过去30天内的日期
            CONCAT('Student', FLOOR(RAND() * 10000)), -- 随机生成用户名
            CONCAT('1', FLOOR(RAND() * 1000000000), FLOOR(RAND() * 10000)), -- 随机生成电话号码
            FLOOR(RAND() * 30) + 1, -- 随机生成年龄（1-30岁）
            IF(RAND() > 0.5, '男', '女'), -- 随机生成性别
            CONCAT('This is a random introduction for student ', FLOOR(RAND() * 10000)) -- 随机生成介绍
        );
        UNTIL ROW_COUNT() = 10 END REPEAT; -- 重复直到插入10条记录

    -- 为每个学生插入10条成绩信息
    INSERT INTO score (scoreName, result, studentId)
    SELECT
        CONCAT('Subject', FLOOR(RAND() * 100)), -- 随机生成科目名
        FLOOR(RAND() * 100), -- 随机生成成绩（0-99分）
        s.id -- 学生ID，来自刚刚插入的学生记录
    FROM (
        SELECT id FROM student ORDER BY id DESC LIMIT 10 -- 获取最后插入的10个学生的ID
    ) AS s
    CROSS JOIN (SELECT 1 n UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9 UNION ALL SELECT 10) AS numbers -- 交叉连接生成10行
    ORDER BY s.id, numbers.n; -- 按学生ID和数字排序以确保每个学生有10条记录
END //

DELIMITER ;
CALL InsertRandomStudentAndScoreData();

问题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。

sql 复制代码

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 ;


-- 尝试将id为1的score记录的scoreName更新为数学
UPDATE score SET scoreName = '数学' WHERE id = 13;


-- 查询score表，查看触发器是否生效
SELECT * FROM score;

问题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。

sql 复制代码

DELIMITER //

CREATE PROCEDURE GetStudentScoresByName(IN p_userName VARCHAR(50))
BEGIN
    -- 声明变量来存储查询结果
    DECLARE done INT DEFAULT FALSE;
    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_scoreName VARCHAR(50);
    DECLARE v_result INT;
    
    -- 声明游标
    DECLARE cur CURSOR FOR 
        SELECT 
            s.createDate, 
            s.userName, 
            s.phone, 
            s.age, 
            s.sex, 
            s.introduce, 
            sc.scoreName, 
            sc.result
        FROM 
            student s
        JOIN 
            score sc ON s.id = sc.studentId
        WHERE 
            s.userName = p_userName;
    
    -- 声明游标的结束处理
    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_createDate, v_userName, v_phone, v_age, v_sex, v_introduce, v_scoreName, v_result;
        IF done THEN
            LEAVE read_loop;
        END IF;
        
        -- 这里你可以选择不同的方式来使用这些数据，比如输出到控制台或返回给调用者
        -- 示例：输出到控制台
        SELECT 
            v_createDate AS createDate, 
            v_userName AS userName, 
            v_phone AS phone, 
            v_age AS age, 
            v_sex AS sex, 
            v_introduce AS introduce, 
            v_scoreName AS scoreName, 
            v_result AS result;
    END LOOP;
    
    -- 关闭游标
    CLOSE cur;
END //

DELIMITER ;
CALL GetStudentScoresByName('张三');