chatgpt输出mysql常用语法汇总

以下是MySQL常用的语法汇总：

1. 创建数据库
   CREATE DATABASE database_name;
2. 删除数据库
   DROP DATABASE database_name;
3. 创建表
   CREATE TABLE table_name (
   column1 datatype,
   column2 datatype,
   column3 datatype,
   ...
   );
4. 删除表
   DROP TABLE table_name;
5. 插入数据
   INSERT INTO table_name (column1, column2, column3, ...) VALUES (value1, value2, value3, ...);
6. 更新数据

UPDATE table_name SET column1 = value1, column2 = value2, ... WHERE condition;

删除数据

DELETE FROM table_name WHERE condition;

查询数据

SELECT column1, column2, ... FROM table_name WHERE condition;

排序

SELECT column1, column2, ... FROM table_name ORDER BY column1 ASC/DESC;

分组

SELECT column1, SUM(column2) FROM table_name GROUP BY column1;

连接

SELECT column1, column2, ... FROM table_name1 JOIN table_name2 ON condition;

子查询

SELECT column1 FROM table_name WHERE column2 = (SELECT column3 FROM table_name2 WHERE condition);

聚合函数

SELECT COUNT(column1), SUM(column2), AVG(column3), MAX(column4), MIN(column5) FROM table_name;

数据类型

INT, BIGINT, FLOAT, DOUBLE, CHAR, VARCHAR, TEXT, DATE, TIME, DATETIME, TIMESTAMP

约束

PRIMARY KEY, FOREIGN KEY, UNIQUE, NOT NULL, CHECK

创建索引

CREATE INDEX index_name ON table_name (column1, column2, ...);

删除索引

DROP INDEX index_name ON table_name;

外键约束

ALTER TABLE table_name ADD FOREIGN KEY (column1) REFERENCES table_name2(column2);

修改表

ALTER TABLE table_name ADD column_name datatype;

删除列

ALTER TABLE table_name DROP column_name;

修改列

ALTER TABLE table_name MODIFY column_name datatype;

添加约束

ALTER TABLE table_name ADD CONSTRAINT constraint_name UNIQUE (column1, column2, ...);

删除约束

ALTER TABLE table_name DROP CONSTRAINT constraint_name;

视图

CREATE VIEW view_name AS SELECT column1, column2, ... FROM table_name WHERE condition;

存储过程

CREATE PROCEDURE procedure_name (IN param1 datatype1, OUT param2 datatype2) BEGIN SELECT column1, column2, ... FROM table_name WHERE condition; END;

触发器

CREATE TRIGGER trigger_name BEFORE/AFTER INSERT/UPDATE/DELETE ON table_name FOR EACH ROW BEGIN ... END;

用户管理

CREATE USER user_name@localhost IDENTIFIED BY 'password';

授权

GRANT SELECT, INSERT, UPDATE, DELETE ON database_name.table_name TO user_name@localhost;

撤销授权

REVOKE SELECT, INSERT, UPDATE, DELETE ON database_name.table_name FROM user_name@localhost;

导入数据

LOAD DATA INFILE 'file_name' INTO TABLE table_name;

导出数据

SELECT column1, column2, ... INTO OUTFILE 'file_name' FROM table_name;