MYSQL 基础入门

来源：互联网发布：app数据接口设计规范编辑：程序博客网时间：2024/06/06 02:22
//创建数据库CREATE DATABASE eshop;//查看数据库SHOW DATABASES;//选择数据库USE eshop;//删除数据库DROP DATABASE eshop;//创建表CREATE TABLE user(userid int auto_increment primary key,username varchar(30) not null,password varchar(30) not null,createtime datetime);//显示表结构SHOW [FULL] COLUMNS FROM user;SHOW [FULL] COLUMNS FROM eshop.user;DESCRIBE user;  //DESCRIBE简写为DESCDESC user username;//添加字段名ALTER TABLE user ADD name varchar(30);//重命名表RENAME TABLE product to ware;//删除表DROP TABLE product；//-------------------------------------//插入记录INSERT INTO user（username,password,createtime) values ('name','password','2015-10-22');//查询记录SELECT * FROM user;//多表查询SELECT * FROM user,product where user.userid=product.userid;//去重复行SELECT DISTINCT class FROM product;//联合多列SELECT userid,contact(username,":",password) as namepassword FROM user;//限定结果行数SELECT * FROM user LIMIT 3;SELECT * FROM user LIMIT 3,3;//修改记录UPDATE product set name='product1' where productid='1';//删除记录DELETE FROM product where id='1';   //如果没有where条件，将会删除所有记录
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