如何捕获动态查询的结果并存储到另一个表中

Question

我有桌子。

查询ID	查询
1	从雇员姓名中选择计数（*）不为空
2	从 id 不为空的部门中选择 count(*)

现在我正在编写一个存储过程来运行查询并将结果存储在目标表中，如下所示：

查询ID	结果
1	2300
2	4500

但是我使用此存储过程得到如下表所示的结果：

查询ID	结果
1	1
2	1

代码：

CREATE PROCEDURE ExecuteQueriesAndStoreResults
AS
BEGIN
    DECLARE @query NVARCHAR(255);
    DECLARE @queryID NVARCHAR(255);

    -- Declare variables for query results
    DECLARE @queryResult NVARCHAR(255);

    -- Declare a cursor to loop through TableA
    DECLARE @curQuery CURSOR;

    SET @curQuery = CURSOR FOR 
       SELECT Query, QueryID 
       FROM TableA;

    OPEN @curQuery;

    FETCH NEXT FROM @curQuery INTO @query, @queryID;

    WHILE @@FETCH_STATUS = 0
    BEGIN
        -- Execute the dynamic query
        EXEC(@query);

        -- Capture the result of the dynamic query
        SET @queryResult = @@ROWCOUNT; -- Store the result as needed
       
        -- Insert the result along with the QueryID into ResultsTable
        INSERT INTO ResultsTable (QueryID, Result)
        VALUES (@queryID, @queryResult);

        FETCH NEXT FROM @curQuery INTO @query, @queryID;
    END;

    CLOSE @curQuery;
    DEALLOCATE @curQuery;
END;

查询ID	结果
1	2300
2	4500

Answer 1

您每次查询都会得到

1

，因为：

SELECT COUNT(*) FROM sys.all_columns;
SELECT @@ROWCOUNT; -- always 1!

假设查询模式是 always...

SELECT {something like a count} and only one row

...你可以这样做：

-- somewhere way above:

DECLARE @sql nvarchar(max);

-- then inside the cursor:

SET @sql = N'WITH cte(rcount) AS ('
  + @query + ') SELECT @QueryID, rcount FROM cte;';

INSERT dbo.ResultsTable(QueryID, Result)
  EXEC sys.sp_executesql @sql, N'@QueryID int', @QueryID;

Answer 2

使用

sp_executesql

而不是

exec

来执行动态 SQL。它允许来回传递参数。

declare @stmt nvarchar(max);
declare @params nvarchar(max);
declare @rowcount int;
set @stmt = N'select @rowcount = count(*) from dbo.YOURTABLE where ID is not null;'
set @params = N'@rowcount int output';
exec sp_executesql @stmt = @stmt
   , @params = @params
   , @rowcount = @rowcount output;
select @rowcount;