exec sp_executesql N'select * from Package where (Status=@s and Title like ''%@t%'') order by Id desc',N'@s int,@t nvarchar(2)',@s=0,@t=N'日租'select * from Package where (Status=0 and Title like '日租') order by Id desc下面一句搜得出来上面一句搜不出
调试欢乐多
--like '%日租%' 我就不用解释了
--like '日租' 相当于 = '日租'
(
Id int identity,
Status int,
Title nvarchar(100)
)
insert #temp
select 0, N'''@t''' union all
select 0, N'%@t%' union all
select 0, N'''日租''' union all
select 0, N'日租'
go
--SQL:
exec sp_executesql N'select * from #temp where (Status=@s and Title like ''%@t%'') order by Id desc',
N'@s int,@t nvarchar(100)', @s=0, @t='日租' --''%@t%' 变量没有被解释成变量
/*
Id Status Title
2 0 %@t%
1 0 '@t'
*/
--写成这样:
exec sp_executesql N'select * from #temp where (Status=@s and Title like @t) order by Id desc',
N'@s int,@t nvarchar(100)', @s=0, @t='%日租%'
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