Question

现在我有一个存储过程，它接受2个表名（作为NVARCHAR）并生成动态SQL来计算两个表的一些比较统计信息，然后使用EXEC sp_executesql来执行动态SQL。

这一切都很有效。

但是我需要一种能够在EXEC dbo.stored_procedure_name之后使用生成的表的方法。我知道这对于存储过程是不可能的，只有函数可以做到这一点。但是函数不能使用动态SQL。

那我怎么能做我需要的呢？我基本上需要某种东西，它需要一些参数，其中两个是表名，并输出一个可以在下游使用的表。

以下是我的存储过程的示例：

-- the stored procedure
CREATE PROCEDURE sp_myTest 
    @t1 NVARCHAR(MAX),
    @t2 NVARCHAR(MAX)
AS
BEGIN
    SET NOCOUNT ON;

    DECLARE @row_count_t1 INT
    DECLARE @row_count_t2 INT
    DECLARE @row_count_difference INT

    DECLARE @SQL NVARCHAR(MAX)

    -- get # of rows in t1
    SET @SQL = N'SELECT @row_count_out = COUNT(*) FROM ' + @t1
    EXEC sp_executesql @SQL, N'@row_count_out INT OUTPUT', @row_count_out = @row_count_t1 OUTPUT;

    -- get # of rows in t2
    SET @SQL = N'SELECT @row_count_out = COUNT(*) FROM ' + @t2
    EXEC sp_executesql @SQL, N'@row_count_out INT OUTPUT', @row_count_out = @row_count_t2 OUTPUT;

    -- calculate difference
    SET @row_count_difference = @row_count_t1 - @row_count_t2

    -- print result
    SET @SQL = N'SELECT @row_count_t1 AS "' + @t1 + '", @row_count_t2 AS "' + @t2 + '", @row_count_difference AS "Row_Count_Difference"'
    EXEC sp_executesql @SQL, N'@row_count_t1 INT, @row_count_t2 INT, @row_count_difference INT', @row_count_t1 = @row_count_t1, @row_count_t2 = @row_count_t2, @row_count_difference = @row_count_difference
END
GO

-- usage
EXEC sp_myTest 'table1', 'table2'

Answer 1

但我需要一种能够在EXEC dbo.stored_procedure_name
之后使用生成的表的方法

据我所知，您可以将数据保存到临时表（或实际表）中如下： -

而不是最后两行： -

 SET @SQL = N'SELECT @row_count_t1 AS "' + @t1 + '", @row_count_t2 AS "' + @t2 + '", @row_count_difference AS "Row_Count_Difference"'
 EXEC sp_executesql @SQL, N'@row_count_t1 INT, @row_count_t2 INT, @row_count_difference INT', @row_count_t1 = @row_count_t1, @row_count_t2 = @row_count_t2, @row_count_difference = @row_count_difference

键入下一行： -

if exists (select 1 from sys.tables where name = 'TblResult')
begin
    Drop table TblResult
    print 'TblResult table has been dropped'
end
-- print result
SET @SQL = N'SELECT @row_count_t1 AS "' + @t1 + '", @row_count_t2 AS "' + @t2 + '", @row_count_difference AS "Row_Count_Difference" into TblResult'

EXEC sp_executesql @SQL, N'@row_count_t1 INT, @row_count_t2 INT, @row_count_difference INT', @row_count_t1 = @row_count_t1, @row_count_t2 = @row_count_t2, @row_count_difference = @row_count_difference

select * from TblResult

修复是： -

使用INTO子句将数据保存到TblResult表中。
要将程序设置为可使用一次而不会出现任何错误，请检查statmnet是否已删除TblResult（如果存在）。
您可以通过在表名开头添加#来使用临时表而不是真实表

现在您的结果将保存到TblResult表中，并根据需要使用它。

Answer 2

  CREATE PROCEDURE sp_myTest 
    @t1 NVARCHAR(MAX),
    @t2 NVARCHAR(MAX)
AS
BEGIN
    SET NOCOUNT ON;
   DECLARE @SQL NVARCHAR(MAX);

   SET @SQL = N'SELECT
                   (SELECT  COUNT(*) FROM ' + @t1+') AS '+@t1+',
                    (SELECT  COUNT(*) FROM ' + @t2+') AS '+@t1+',
                    ((SELECT  COUNT(*) FROM ' + @t1+') - (SELECT  COUNT(*) FROM ' + @t2+')) AS row_count_difference;'

    EXEC sp_executesql @SQL;

    END;

返回可以使用动态表名称使用的表的函数或存储过程

2 个答案: