我先设置一表名:DECLARE @TabName nvarchar(50) = '表1'/*下面全用这个表名,怎么弄?select * from @TabName
网上有说这样的
@SQL = 'select * from ' + @TabName
exec sp_executesql @SQL
但是这样感觉不好
网上有说这样的
@SQL = 'select * from ' + @TabName
exec sp_executesql @SQL
但是这样感觉不好
exec(@SQL)这样感觉如何?如果表名为可变的,那就得用这样的动态查询,感觉不好也得这样.
/******************************************************************************************************************************************************
动态语句语法:exec\sp_executesql语法整理人:中国风(Roy)日期:2008.06.06
******************************************************************************************************************************************************/
动态语句语法:--方法1查询表改为动态
select * from sysobjects
exec('select ID,Name from sysobjects')
exec sp_executesql N'select ID,Name from sysobjects'--多了一个N为unicode--方法2:字段名,表名,数据库名之类作为变量时,用动态SQL
declare @FName varchar(20)
set @FName='ID'
exec('select '+@FName+' from sysobjects where '+@FName+'=5' )
declare @s varchar(1000)
set @s=N'select '+@FName+' from sysobjects where '+@FName+'=5'
exec sp_executesql @s--会报错
declare @s nvarchar(1000)--改为nvarchar
set @s=N'select '+@FName+' from sysobjects where '+@FName+'=5'
exec sp_executesql @s--成功
--方法3:输入参数declare @i int,@s nvarchar(1000)
set @i=5
exec('select ID,Name from sysobjects where ID='+@i)set @s='select ID,Name from sysobjects where ID=@i'
exec sp_executesql @s,N'@i int',@i--此处输入参数要加上N--方法4:输出参数declare @i int,@s nvarchar(1000)
set @s='select @i=count(1) from sysobjects'--用exec
exec('declare @i int '+@s+' select @i')--把整个语句用字符串加起来执行--用sp_executesql
exec sp_executesql @s,N'@i int output',@i output--此处输出参数要加上N
select @i
--方法5:输入输出--用sp_executesql
declare @i int,@con int,@s nvarchar(1000)
set @i=5
select @s='select @con=count(1) from sysobjects where ID>@i'
exec sp_executesql @s,N'@con int output,@i int',@con output ,@i
select @con--用exec
declare @i int,@s nvarchar(1000)
set @i=5
select @s='declare @con int select @con=count(1) from sysobjects where ID>'+rtrim(@i)+' select @con'
exec(@s)
FROM '+ @TableName +'
WHERE (( [学号]) In (SELECT [学号] FROM 软件0902电子0901
As Tmp GROUP BY [学号] HAVING Count(*)>1 ))'
exec (@SQL)
有沒有 聲明變量
declare @SQL nvarchar(4000)SET @TableName='表名'--輸入SELECT @SQL = 'SELECT [学号],[姓名]
FROM ['+ @TableName +']
WHERE (( [学号]) In (SELECT [学号] FROM 软件0902电子0901
As Tmp GROUP BY [学号] HAVING Count(*)>1 ))'
exec (@SQL)
DECLARE @TableName nvarchar(50)='软件0902电子0901'
DECLARE @SQL nvarchar(50)
語句也有問題,group by 與select的列名不一致declare @SQL nvarchar(4000),@TableName sysnameSET @TableName=N'表名'--輸入SELECT @SQL = N'SELECT [学号],[姓名]
FROM ['+ @TableName +N']
WHERE (( [学号]) In (SELECT [学号] FROM [软件0902电子0901]
As Tmp GROUP BY [学号],[姓名] HAVING Count(*)>1 ))'
EXEC( @SQL)
IF EXISTS(EXEC (@SQL))
--如何判断他是不是为空啊?
FROM '+ @TableName +'
WHERE (( [学号]) In (SELECT [学号] FROM '+@TableName+'
As Tmp GROUP BY [学号] HAVING Count(*)>1 ))'
IF EXISTS(EXEC (@SQL))
begin
end
然后insert into #tb exec(@sql)
再判断。
能把你的語句貼全麼?IF EXISTS(EXEC (@SQL))--這是語法錯誤,你要學會方法,在上面都有動態寫法
FROM '+ @TableName +'
WHERE (( [学号]) In (SELECT [学号] FROM '+@TableName+'
As Tmp GROUP BY [学号] HAVING Count(*)>1 ))
if @@rowcount>0
begin
select N''有記錄''
end
'
EXEC (@SQL)全放在字符串里