存储过程中字符串的拼接问题
我些了一个存储过程：
ALTER PROC [dbo].[GetStockBySingleStorageType]
@condition varchar(500)
AS
BEGIN
DECLARE @s varchar(5000)
SET @s= 'BoDuanId,ProductStyle ,ProductColor,
convert(decimal(38,2),Price) as 单价 '
select @s=@s+ ',sum( CASE SizeName WHEN ' ' '+SizeName+ ' ' ' THEN
Stock.nquantity ELSE 0 END) AS [ '+SizeName+ '] ' from vProduct2Chinese
INNER JOIN stock ON stock.ProductCode=vProduct2Chinese.ProductCode
INNER JOIN StorageType ON StorageType.[id]=Stock.StorageType
where 1=1 ?????????(这儿不知道如何把@condition传到这儿，总是出错，我郁闷了，大家给个方法吧)
group by ProductSize,SizeName order by ProductSize
exec( 'SELECT '+@s+ ',sum(nquantity) AS 小计,
convert(decimal(38,2),price*sum(nquantity)) as 金额
from vProduct2Chinese
INNER JOIN stock ON stock.ProductCode=vProduct2Chinese.ProductCode
INNER JOIN StorageType ON StorageType.[id]=Stock.StorageType
where 1=1 '+@condition+ '
group by BoDuanId,ProductStyle,ProductColor,Price
order by BoDuanId,ProductStyle,ProductColor
')
END
[解决办法]
--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
--------------------------------------------
动态sql语句基本语法
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
[解决办法]
@condition 查询条件是变量串?
那只有用动态SQL的嵌套了，即：动态SQL中，再用动态SQL。
