mysql的sql语句大全

SELECT * FROM users; -- 获取users表中的所有记录
SELECT id, name FROM users WHERE age > 25; -- 获取年龄大于25岁的用户的id和name

INSERT INTO users (name, age) VALUES ('Alice', 30); -- 向users表中插入一条新记录

UPDATE users SET age = 31 WHERE name = 'Alice'; -- 将名为Alice的用户年龄更新为31

DELETE FROM users WHERE id = 1; -- 删除id为1的用户记录

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(100),
    age INT
); -- 创建一个名为users的表

ALTER TABLE users ADD COLUMN email VARCHAR(100); -- 向users表中添加一个email列

DROP TABLE users; -- 删除users表

CREATE INDEX idx_name ON users(name); -- 在users表的name列上创建索引
DROP INDEX idx_name ON users; -- 删除users表上的idx_name索引

CREATE VIEW user_view AS SELECT name, age FROM users WHERE age > 25; -- 创建一个视图
DROP VIEW user_view; -- 删除视图

DELIMITER //
CREATE PROCEDURE GetUsersByAge(IN min_age INT)
BEGIN
    SELECT * FROM users WHERE age >= min_age;
END //
DELIMITER ;
CALL GetUsersByAge(25); -- 调用存储过程

DELIMITER //
CREATE FUNCTION GetAge(user_id INT) RETURNS INT
BEGIN
    DECLARE u_age INT;
    SELECT age INTO u_age FROM users WHERE id = user_id;
    RETURN u_age;
END //
DELIMITER ;
SELECT GetAge(1) AS age; -- 调用函数