Question

下面是我在T-SQL中的存储过程。我有两个参数@id和@questionId。 Select语句使用两个参数进行选择。

我正在寻找的方法是如果参数的值为0则不使用条件。详细地，如果@id的值为0，则过滤pa.Id = @id不应执行的地方以及@questionId =0时，并且pa.QuestionId = @questionId不应执行。

ALTER PROCEDURE[dbo].[spOptions] 
    (@id INT, @questionId INT)
AS
BEGIN   
    SELECT * 
    FROM PossibleAnswers pa
    INNER JOIN vFormAnswers fa ON pa.QuestionId = fa.QuestionId
    WHERE pa.Id = @id 
      AND pa.QuestionId = @questionId
END
GO

Answer 1

您可以尝试一下。在这里，如果将参数传递为0，则它将执行或条件0 = 0（为true）并考虑所有记录。

ALTER PROCEDURE[dbo].[spOptions] 
(  @id int=0, @questionId int=0  )  ---- here pass default value as 0 so this is optional to pass from front end
AS
BEGIN   
select * from PossibleAnswers pa
inner join  vFormAnswers fa
on pa.QuestionId = fa.QuestionId
where (pa.Id = @id or @id = 0)    ---- here if @id = 0 then condition will be 0=0 
and (pa.QuestionId = @questionId or @questionId=0)
END
GO

如何根据条件在T-SQL select语句中执行where子句

1 个答案: