mysql常用语句

1.查看所有的数据库

show databases;

2.使用xx数据库

use xx

3.创建xx数据库

create database if not exists `xx`;

4.查看所有的表

show tables;

5.创建xx表

create table if not exists `xx` (
    `id` bigint not null AUTO_INCREMENT,
    ....
    `fk_id` bigint not null,
    primary key (`id`),
    CONSTRAINT `fk1_xx`
    FOREIGN KEY (`fk_id`)
    REFERENCES `f_xx` (`id`)
    ON DELETE CASCADE ON UPDATE CASCADE
)ENGINE=InnoDB default charset=utf8;

6.移除xx表的外键

ALTER TABLE `xx` DROP FOREIGN KEY `fk1_xx`;

7.查看xx表的表结构

  7_1.desc `xx`;

  7_2.show create table `xx`