仅执行动态查询以获得受影响的行数

Question

我想执行动态查询以获取受影响的行数。但是 SQL 结果窗格 returns 我执行后的结果。如何避免返回列。我尝试了下面的方法。

DECLARE @Command NVARCHAR(MAX)= 'SELECT * FROM Product  WHERE ID = 12'
DECLARE @Count AS INT
EXEC sp_executesql @Command, N'@C INT OUTPUT', @C=@Count OUTPUT
  IF (@Count > 0)
   BEGIN
    EXECUTE (@Command)
   END
  ELSE
   BEGIN
    DECLARE @CatalogProduct VARCHAR(MAX) = 'SELECT p.ManufactureCode,p.PartNo,p.Size,p.ID AS ProductID,p.Name ,p.ParentProductID,p.BasePrice FROM Product.Product p WHERE p.ThruDate > GETDATE() '+@Where
            EXECUTE (@CatalogProduct)
   END
END

我想避免返回上图中的空列集。

Answer 1

您可以关闭显示，但我认为更好的方法是直接获取您想要的计数：

DECLARE @Command NVARCHAR(MAX)= 'SELECT * FROM Product  WHERE ID = 12';

DECLARE @count AS INT;
DECLARE @CntCommand NVARCHAR(MAX);

SET @CntCommand = 'SELECT @count = COUNT(*) FROM (' + @Command + ') x)';

EXEC sp_executesql @CntCommand, N'@count INT OUTPUT', @count=@count OUTPUT;

Answer 2

为什么不简单呢？

IF (SELECT COUNT(*) FROM Product = 12) > 0 BEGIN...

我不明白为什么 COUNT 语句需要是动态的；没有什么动态的。

另外，SQL '... WHERE p.ThruDate > GETDATE() '+@Where 是个糟糕的主意。如果 @where 是参数，它将 wide 开放给 SQL 注入。

Answer 3

试试这个。 Returns 上次查询影响的行数： select @@Rowcount

Answer 4

DECLARE @Command NVARCHAR(MAX)= 'SELECT * FROM Product  WHERE ID = 12'
DECLARE @CountCommand NVARCHAR(MAX)= 'SELECT @Count=count(1) FROM Product  WHERE ID = 12'
DECLARE @Count AS INT
EXEC sp_executesql @CountCommand , N'@Count INT OUTPUT', @Count=@Count OUTPUT
  IF (@Count > 0)
   BEGIN
    EXECUTE (@Command)
   END
  ELSE
   BEGIN
    DECLARE @CatalogProduct VARCHAR(MAX) = 'SELECT p.ManufactureCode,p.PartNo,p.Size,p.ID AS ProductID,p.Name ,p.ParentProductID,p.BasePrice FROM Product.Product p WHERE p.ThruDate > GETDATE() '+@Where
            EXECUTE (@CatalogProduct)
   END
END

仅执行动态查询以获得受影响的行数

Execute dynamic query only to get affected row count

sql

sql-server

execute

dynamicquery