在存储过程的where子句中使用If

Question

我正在编写一个包含3个参数的存储过程,并且我的where子句根据这些参数之一而改变.是否有可能以这种方式编写SQL查询 -

    CREATE PROCEDURE [dbo].[VendorVettingModal] @column NVarchar (50), @applicanttype NVarchar (10), @donotuse int AS

                declare @column NVarchar (50), @applicanttype NVarchar (10), @donotuse int

    select a.Id, a.Firstname, rs.Status,cs.ClearanceStatus
    from applicant a 
    left join ReviewStatus rs on a.ReviewStatus = rs.Id 
    left join ClearanceStatus cs on a.ClearanceStatus = cs.Id
    where
    if(@column = 'Recruiting')
    begin
        a.applicanttype = @applicanttype and a.reviewstatus = 7 and a.donotuse = @donotuse      
    end
    else if(@column = 'Clearance')
    begin
        a.applicanttype = @applicanttype and (a.reviewstatus != 7 or a.reviewstatus is null) and a.donotuse = @donotuse     
    end 

而不是这样写？因为我有大约20-25列和更多的连接和params比这里定义的更多.我刚刚试图让它变得不那么复杂.

    CREATE PROCEDURE [dbo].[VendorVettingModal] @column NVarchar (50), @applicanttype NVarchar (10), @donotuse int AS

                declare @column NVarchar (50), @applicanttype NVarchar (10), @donotuse int

    if(@column = 'Recruiting')
    begin
        select a.Id, a.Firstname, rs.Status,cs.ClearanceStatus
        from applicant a 
        left join ReviewStatus rs on a.ReviewStatus = rs.Id 
        left join ClearanceStatus cs on a.ClearanceStatus = cs.Id
        where
        a.applicanttype = @applicanttype and a.reviewstatus = 7 and a.donotuse = @donotuse      
    end
    else if(@column = 'Clearance')
    begin
        select a.Id, a.Firstname, rs.Status,cs.ClearanceStatus
        from applicant a 
        left join ReviewStatus rs on a.ReviewStatus = rs.Id 
        left join ClearanceStatus cs on a.ClearanceStatus = cs.Id
        where
        a.applicanttype = @applicanttype and (a.reviewstatus != 7 or a.reviewstatus is null) and a.donotuse = @donotuse     
    end 

Answer 1

使用括号:

 select a.Id, a.Firstname, rs.Status,cs.ClearanceStatus
    from applicant a 
    left join ReviewStatus rs on a.ReviewStatus = rs.Id 
    left join ClearanceStatus cs on a.ClearanceStatus = cs.Id
    where a.applicanttype = @applicanttype
    and a.donotuse = @donotuse 
    AND ((@column = 'Recruiting' AND (a.reviewstatus = 7))
    OR
    (@column = 'Clearance' AND (a.reviewstatus != 7 or a.reviewstatus is null)))