如果stmt使用NoRows或Int？ SQL

Question

我对最好的解决方法一无所知。目前的查询很好。问题是如果没有返回行，我希望if语句为true。我也不想两次编写查询，所以我如何以if语句为真并运行的方式编写它？

IF (select AnInt from ATable where Cond) = expectedInt
begin ... end

Answer 1

如果无法使用NULL AnInt，则可以将无匹配时的空子选择结果设为expectedInt

IF isnull((select AnInt from ATable where Cond), expectedInt) = expectedInt

Answer 2

喜欢这样吗？

DECLARE @Test INT

SELECT @Test = AnInt
FROM ATable
WHERE Cond

IF @Test IS NULL OR @Test = expectedInt
BEGIN
...
END

Answer 3

IF Coalesce((select TOP 1 AnInt from ATable where Cond),expectedInt) = expectedInt
begin
end