Question

我有一个SQL查询，我正在使用distinct语句

   CREATE proc SProc_SelectPhotographersByLocation         
@locationID varchar(500)          
as            
begin          


DECLARE @TEST varchar(1000)          
DECLARE @SQLQuery AS NVARCHAR(1000)          

SET @TEST = @locationID          

SET @SQLQuery = 'select distinct ContributerSubCategoryMapping.ContributorID,  PhotographerContributors_tbl.*  from ContributerSubCategoryMapping               
  left outer join PhotographerContributors_tbl on PhotographerContributors_tbl.ContributorId=ContributerSubCategoryMapping.ContributorID              
  left outer join tbl_City on tbl_City.CityID=PhotographerContributors_tbl.Location              
  where         
  PhotographerContributors_tbl.Location IN('+ @locationID +') and PhotographerContributors_tbl.IsActive=''1'' order by Newid()'          
EXECUTE(@SQLQuery)          

end

当我在该查询上使用NEWID()时，我的查询出错了。错误是

如果指定了SELECT DISTINCT，则ORDER BY项必须出现在选择列表中。

请帮我解决这个问题

Answer 1

使用group by代替distinct。一种方法是明确列出列：

select csm.ContributorID, pc.col1, pc.col2, . . .
from ContributerSubCategoryMapping csm left outer join
     PhotographerContributors_tbl pc
     on pc.ContributorId = csm.ContributorID left outer join
     tbl_City c
     on c.CityID = pc.Location              
where pc.Location IN ('+ @locationID +') and pc.IsActive=''1''
group by csm.ConstributorId, pc.col1, pc.col2, . . .
order by Newid();

但是，我不明白查询。表ContributerSubCategoryMapping和tbl_City似乎没有被使用。那么为什么不这样做？

select pc.*
from PhotographerContributors_tbl pc
where pc.Location IN ('+ @locationID +') and pc.IsActive=''1''
order by Newid();

使用NEWID（）从表中检索随机行

1 个答案: