随笔分类 -  MYSQL

摘要:目前有两个类:机构、职员 package com.common.vo; public class Org{ public long id; public String name; public String desc; } package com.common.vo; public class Em 阅读全文
posted @ 2020-10-27 16:21 bud 阅读(255) 评论(0) 推荐(0)
摘要:登录linux服务器成功后: 登录mysql: mysql -uroot -p 输入密码:xxxx 创建数据库: create database test 创建用户及密码: create user 'user'@'%' identified by 'password'; 用户赋权: grant al 阅读全文
posted @ 2020-08-12 10:09 bud 阅读(1462) 评论(0) 推荐(0)
摘要:方法一: select IF(ISNULL(columnName) OR columnName='',0,columnName) from tableName; 方法二: select case when ISNULL(columnName) OR columnName='' then 0 else 阅读全文
posted @ 2020-01-10 16:53 bud 阅读(1120) 评论(0) 推荐(0)
摘要:1.根据名称分组去重,并查询记录ID select max(id) from T_TABLE GROUP BY name 2.根据ID获取记录 select * from T_TABLE where ID in ( select max(id) from T_TABLE GROUP BY name 阅读全文
posted @ 2019-11-18 16:20 bud 阅读(504) 评论(0) 推荐(0)