CREATE function F_Str(@Col1 int,@Type bit)
returns nvarchar(100)
as
begin
declare @S nvarchar(100)
select @S=isnull(@S+',','')+fieldabc from tableabc where fieldid=@Col1
return @S
end
如上函数,要将字段和表fieldabc ,tableabc和fieldid都改为可作为@fieldabc ,@tableabc和@fieldid参数输入,应该如何写?
returns nvarchar(100)
as
begin
declare @S nvarchar(100)
select @S=isnull(@S+',','')+fieldabc from tableabc where fieldid=@Col1
return @S
end
如上函数,要将字段和表fieldabc ,tableabc和fieldid都改为可作为@fieldabc ,@tableabc和@fieldid参数输入,应该如何写?
1 :普通SQL语句可以用Exec执行 eg: Select * from tableName
Exec('select * from tableName')
Exec sp_executesql N'select * from tableName' -- 请注意字符串前一定要加N 2:字段名,表名,数据库名之类作为变量时,必须用动态SQL eg:
declare @fname varchar(20)
set @fname = 'FiledName'
Select @fname from tableName -- 错误,不会提示错误,但结果为固定值FiledName,并非所要。
Exec('select ' + @fname + ' from tableName') -- 请注意 加号前后的 单引号的边上加空格 当然将字符串改成变量的形式也可
declare @fname varchar(20)
set @fname = 'FiledName' --设置字段名 declare @s varchar(1000)
set @s = 'select ' + @fname + ' from tableName'
Exec(@s) -- 成功
exec sp_executesql @s -- 此句会报错 declare @s Nvarchar(1000) -- 注意此处改为nvarchar(1000)
set @s = 'select ' + @fname + ' from tableName'
Exec(@s) -- 成功
exec sp_executesql @s -- 此句正确 3. 输出参数
declare @num int,
@sqls nvarchar(4000)
set @sqls='select count(*) from tableName'
exec(@sqls)
--如何将exec执行结果放入变量中? declare @num int,
@sqls nvarchar(4000)
set @sqls='select @a=count(*) from tableName '
exec sp_executesql @sqls,N'@a int output',@num output
select @num
create proc wsp
@tableabc varchar(50),
@fieldabc varchar(50),
@fieldid varchar(50)
as
declare @sql nvarchar(1000),@rs varchar(100)
set @sql='select @S=isnull(@S+'','','''')+'+@fieldabc+' from '+@tableabc+' where fieldid='''+@fieldid+''''
exec sp_executesql @sql,N'@s varchar(100) output',@rs output
select @rs
go
exec wsp '表名','字段名','id'
Returns Varchar(1000)
As
Begin
Declare @S Varchar(1000)
Set @S=''
Select @S=@S+','+ sh from ht_m ,ht_z Where ht_m.htbh=ht_z.htbh and ht_z.htbh=@htbh
Return (Stuff(@S,1,1,''))
End