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基本上我正在尝试对仅包含图像的页面进行查询。我需要提供tripID 号码，然后提供ROWID（因为可能有多个图像）来接收单个图像。我将循环直到每个图像都在 html 中相应的图像框中。

此代码似乎不起作用（我得到 Invalid column name 'ROWID'），但如果我删除 AND ROWID='1' 它会返回所有图像及其行 ID，如下所示：

ROWID      PHOTO
    1      32jjr3h2jh23hj4h32jh42ll23j42 
    2       HU8308DJAOID9ASIDJI32C89EE29

-

Select ROW_NUMBER() OVER (ORDER BY Photo ASC) AS ROWID, TBL_Photo.Photo
        From TBL_Photo
        left join TBL_TripDetails
        ON TBL_Photo.TripID=TBL_TripDetails.pkiTripID
        Where pkiTripID = '121' AND ROWID = '1'
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1 回答 1

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You can't reference a column alias in the WHERE clause -- you need to use a subquery or a CTE:

Subquery Example:

SELECT x.rowid,
       x.photo
  FROM (SELECT ROW_NUMBER() OVER (ORDER BY p.photo) AS ROWID, 
               p.photo
          FROM TBL_PHOTO p
     LEFT JOIN TBL_TRIPDETAILS td ON td.pkitripid = p.tripid 
         WHERE td.pkiTripID = '121') x
 WHERE x.rowid = 1

CTE example:

WITH example AS (
        SELECT ROW_NUMBER() OVER (ORDER BY p.photo) AS ROWID, 
               p.photo
          FROM TBL_PHOTO p
     LEFT JOIN TBL_TRIPDETAILS td ON td.pkitripid = p.tripid 
         WHERE td.pkiTripID = '121')
SELECT x.rowid,
       x.photo
  FROM example x
 WHERE x.rowid = 1

Performance

There's no performance difference between the two options, but the WITH syntax isn't supported on all databases.

于 2010-11-18T18:56:59.010 回答