复制代码 代码如下: --执行顺序 From Where Select select * from (select sal as salary,comm as commission from emp ) x where salary5000 --得出 Name Work as a Job select ename +' Work as a'+job as msg from emp where de
mysql查询日期中的月份的方法：执行【SELECT FROM BLOG WHERE MONTH(CREATETIME)=7;】语句即可。 获取月份 （推荐教程：mysql教程） SELECT FROM BLOG WHERE MONTH(CREATETIME)=7; 获取年份 SELECT * FROM BLOG WH
mysql查询30天内的数据的方法：执行sql语句【SELECT FROM 表名 where DATE_SUB(CURDATE(), INTERVAL 30 DAY) = date(时间字段名);】即可。 今天： （推荐教程：mysql教程） SELECT FROM 表名 WHERE TO_DAYS( 时间
聚合函数 count,max,min,avg,sum... select count () from T_Employee select Max(FSalary) from T_Employee 排序 ASC升序 DESC降序 select from T_Employee order by Fage 先按年龄降序排列。如果年龄相同，则按薪水升序排 聚合函数 count,max,min,avg,su
复制代码 代码如下: Select * from T_Employee select FName,FAge from T_Employee select FName from T_Employee where FSalary 5000 select FName as 姓名,FAge as 年龄,FSalary as 月薪from T_Employee where FSalary 5000 sele
复制代码 代码如下: USE TestDB declare @conversation uniqueidentifier while exists (select 1 from sys.transmission_queue ) begin set @conversation = (select top 1 conversation_handle from sys.transmission_queu
复制代码 代码如下: --代码一DECLARE @cc INT SELECT NewsId,ROW_NUMBER() OVER(ORDER BY SortNum DESC) AS RowIndex INTO #tb FROM news WITH(NOLOCK) WHERE NewsTypeId=@NewsTypeId AND IsShow=1 SET @cc = @@ROWCOUNT SELECT
基本常用查询 --select select from student; --all 查询所有 select all sex from student; --distinct 过滤重复 select distinct sex from student; --count 统计 select count() from student; select count(sex) from student; s
查询本日记录 SELECT FROM messages WHERE CONVERT(Nvarchar, CreateDate, 111) = CONVERT(Nvarchar, GETDATE(), 111) ORDER BY CreateDate DESC SELECT FROM 表 WHERE datediff(day, 列名 ,getdate())=0 查询本年 SELECT count(*
复制代码 代码如下: -判断某些字段是否为空 --case select case when '字段名' is null then '\N' else convert(varchar(20),'字段名') end as 'NewName' select case when null is null then '\N' else convert(varchar(20),null) e 复制代码 代码
