列名无效

Question

SELECT Ad.Id, Newspaper, 
    (select Organization from JobOrganization where JobOrganization.Id = Ad.OrganizationId) as Organization,
    Ad.PublishDate, Ad.LastDate,Ad.Url, Job.Id as JobId,
    (select JobTitle from JobTitle where JobTitle.Id = Job.TitleId) as JobTitle1,
    QualificationId, ExpInYears, CategoryId
     FROM Ad inner join Job on Ad.Id = Job.AdId
     Where JobTitle1 Like @title or @title is null
     Order by
 case When @sortCol='PublishDate' and @sortDir='ASC' Then Ad.PublishDate End ASC,
 case When @sortCol='PublishDate' and @sortDir='DESC' Then Ad.PublishDate End DESC,
 case When @sortCol='LastDate' and @sortDir='ASC' Then Ad.LastDate End ASC,
 case When @sortCol='LastDate' and @sortDir='DESC' Then Ad.LastDate End DESC

错误：列名'JobTitle1'无效。

我正在使用SQL-2008

Answer 1

我担心你不能在where子句中使用别名，

    SELECT Ad.Id, Newspaper, 
    (select Organization from JobOrganization where JobOrganization.Id = Ad.OrganizationId) as Organization,
    Ad.PublishDate, Ad.LastDate,Ad.Url, Job.Id as JobId,
    (select JobTitle from JobTitle where JobTitle.Id = Job.TitleId) as JobTitle1,
    QualificationId, ExpInYears, CategoryId
     FROM Ad inner join Job on Ad.Id = Job.AdId
     Where (select JobTitle from JobTitle where JobTitle.Id = Job.TitleId)Like @title or @title is null
     Order by
 case When @sortCol='PublishDate' and @sortDir='ASC' Then Ad.PublishDate End ASC,
 case When @sortCol='PublishDate' and @sortDir='DESC' Then Ad.PublishDate End DESC,
 case When @sortCol='LastDate' and @sortDir='ASC' Then Ad.LastDate End ASC,
 case When @sortCol='LastDate' and @sortDir='DESC' Then Ad.LastDate End DESC

所以在那种情况下我正在使用View ..

Answer 2

此处缺少JobTitle1引用名称范围（其中 JobTitle1 像@title或@title一样为null）， 试试这个( Where Ad.JobTitle1 Like @title or @title is null )

Answer 3

您不能在WHERE子句中使用别名，因为WHERE子句是在SELECT子句之前计算的。