存储过程，必须声明标量变量问题

[xjc55]

各位朋友
以下是我写的一个存储过程分页方法，能够编译通过，但是在使用时，老是提示“消息 137，级别 15，状态 1，第 1 行
必须声明标量变量 "@TotalCount"。”请看
CREATE PROCEDURE Pagination
@TotalCount INT OUTPUT,
@TotalPage INT OUTPUT,
@Table NVARCHAR(25), --将要查询的表名
@Column NVARCHAR(150),--将要查询的字段，可多列
@OrderColumn NVARCHAR(50), --排序字段
@CountColumn NVARCHAR(20), --取这个字段的最大值
@PageSize INT,--分页大小
@CurrentPage INT, --要查询的页
@OrderType NVARCHAR(4),--如何排序
@Condition NVARCHAR(200) --查询条件
AS
DECLARE @PageCount INT,
@strSql NVARCHAR(500),
@strCount NVARCHAR(100)
SET @PageCount=@PageSize*@CurrentPage
BEGIN
IF @Condition!='NO'
BEGIN
SET @strCount='SELECT @TotalCount=COUNT(*) FROM '+ @Table + ' WHERE '+@Condition
SET @TotalPage=CEILING(str(@TotalCount/@PageSize))
SET @strSql='SELECT TOP '+ str(@PageSize) +' '+ @Column +' FROM '+ @Table + '
WHERE ' + @CountColumn + '>(SELECT MAX('+ @CountColumn +')
FROM (SELECT TOP ' + str(@PageCount)+' '+ @CountColumn+'
FROM ' + @Table + ' ORDER BY ' + @CountColumn +') AS T) AND '+ @Condition + ' ORDER BY ' + @OrderColumn +' '+ @OrderType
END
ELSE
BEGIN
SET @strCount='SELECT @TotalCount=COUNT(*) FROM '+ @Table
SET @TotalPage=CEILING(str(@TotalCount/@PageSize))
SET @strSql='SELECT TOP '+ str(@PageSize) +' '+ @Column +' FROM '+ @Table + '
WHERE ' + @CountColumn + '>(SELECT MAX('+ @CountColumn +')
FROM (SELECT TOP ' + str(@PageCount)+' '+ @CountColumn+'
FROM ' + @Table + ' ORDER BY ' + @CountColumn +') AS T)
ORDER BY ' + @OrderColumn +' '+ @OrderType
END
EXEC (@strCount)
EXEC (@strSql)
END

下面是我在asp.net2.0中进行调用
public DataTable ShowBook(MShowBook mshowbook)
{
SqlParameter[] parms = new SqlParameter[10];
parms[0] = lzjbook.ParaInstance("@Pagesize", SqlDbType.Int, 4, mshowbook.Pagesize, ParameterDirection.Input);
parms[1] = lzjbook.ParaInstance("@CurrentPage", SqlDbType.Int, 4, mshowbook.CureentPage, ParameterDirection.Input);
parms[2] = lzjbook.ParaInstance("@OrderType", SqlDbType.NVarChar, 4, mshowbook.OrderType, ParameterDirection.Input);
parms[3] = lzjbook.ParaInstance("@TotalCount", SqlDbType.Int, 4, null, ParameterDirection.Output);
parms[4] = lzjbook.ParaInstance("@TotalPage", SqlDbType.Int, 4, null, ParameterDirection.Output);
parms[5] = lzjbook.ParaInstance("@Table", SqlDbType.NVarChar, 25, "MainBook", ParameterDirection.Input);
parms[6] = lzjbook.ParaInstance("@Column", SqlDbType.NVarChar, 150, "BookName", ParameterDirection.Input);
parms[7] = lzjbook.ParaInstance("@OrderColumn", SqlDbType.NVarChar, 50, "AddTime", ParameterDirection.Input);
parms[8] = lzjbook.ParaInstance("@CountColumn", SqlDbType.NVarChar, 20, "BookID", ParameterDirection.Input);
parms[9] = lzjbook.ParaInstance("@Condition", SqlDbType.NVarChar, 200, "bookname='图书名'", ParameterDirection.Input);
DataTable dt = new DataTable();
try
{
dt = lzjbook.GetOneRecord("Pagination", CommandType.StoredProcedure, parms);
}
catch (Exception e)
{
if (e != null)
{
HttpContext.Current.Response.Redirect("Error.aspx?errorMsg=对不起，在函数执行期间出现了错误，给您带来不便表示歉意，请稍后再试！");
}
}
finally
{
lzjbook.Close();
}
return dt;

}

参数都传进去，就是出现“消息 137，级别 15，状态 1，第 1 行
必须声明标量变量 "@TotalCount"。”
我的这个方法我测试过了，没有问题的
请各位帮我看看，感激不尽

[lang8134]

这句换下
EXEC (@strCount)
----------------------------------------------------------------------------------
exec sp_executesql @strCount,N'TotalCount int output',@TotalCount output
你这个属于动态sql带传出参数的.
可以参考下sp_executesql的用法.

[Limperator]

SET @strCount='SELECT @TotalCount=COUNT(*) FROM '+ @Table + ' WHERE '+@Condition
SET @strCount='SELECT @TotalCount=COUNT(*) FROM '+ @Table


上面两句要用sp_executesql才能把COUNT(*)结果提取出来。

[lang8134]

不好意思,少写了个@.

[comszsoft]

EXEC (@strCount)
EXEC (@strSql)
END

-- modify to
EXEC sp_executesql @strCount,N'@totalcount int output',@totalcount output
EXEC (@strSql)
END

[OracleRoob]

--如何从动态SQL中返回数值？

--如何将exec执行结果放入变量中？

declare @num int, @sql nvarchar(4000)
set @sql='select @a=count(*) from tableName '
exec sp_executesql @sql,N'@a int output',@num output
select @num

[OracleRoob]

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, @sql nvarchar(4000)
set @sql='select count(*) from tableName'
exec(@sql)


--如何将exec执行结果放入变量中？

declare @num int, @sql nvarchar(4000)
set @sql='select @a=count(*) from tableName '
exec sp_executesql @sql,N'@a int output',@num output
select @num

[Limperator]

修改两处：

SET @strCount='SELECT @TotalCount=COUNT(*) FROM '+ @Table + ' WHERE '+@Condition
exec sp_executesql @strCount, N'@TotalCount int output', @TotalCount output
SET @TotalPage=CEILING(str(@TotalCount/@PageSize))

SET @strCount='SELECT @TotalCount=COUNT(*) FROM '+ @Table
exec sp_executesql @strCount, N'@TotalCount int output', @TotalCount output
SET @TotalPage=CEILING(str(@TotalCount/@PageSize))

后面那一行：EXEC (@strCount)，注释或删除。