Question

我在这里选择：

SELECT * FROM (
    SELECT DISTINCT cod_arq, 
           (SELECT description FROM [serverTwo].[perg].dbo.marc_section WHERE paragraph = 10 AND cod_arq = AC.cod_arq) AS author,
           (SELECT description FROM [serverTwo].[perg].dbo.marc_section WHERE paragraph = 24 AND cod_arq = AC.cod_arq) AS title,
           (SELECT description FROM [serverTwo].[perg].dbo.marc_section WHERE paragraph = 25 AND cod_arq = AC.cod_arq) AS edt
    FROM [serverTwo].[pergamarc].dbo.marc_section AC
) AS ACN
WHERE ACN.author IS NOT NULL 
    AND ACN.title IS NOT NULL

我在serverOne上测试了一些sql到serverTwo，没关系，我可以从一台服务器调用它们到另一台服务器。但是如果我在＆＃34; serverTwo＆＃34;上运行它，那么上面的sql工作正常。（表示sintaxe是正确的），但如果我从serverOne运行它，则不行。但是，如果我删除了DISTINCT关键字，它就可以工作（显示重复的行，但有效）。

这个DISTINCT可能会发生什么？也许有些COLLATE冲突？

Answer 1

我认为你只想要条件聚合：

SELECT acn.*
FROM (SELECT ac.cod_arq, 
           MAX(CASE WHEN paragraph = 10 THEN description END) as author,
           MAX(CASE WHEN paragraph = 24 THEN description END) as title,
           MAX(CASE WHEN paragraph = 25 THEN description END) as edt
      FROM [serverTwo].[pergamarc].dbo.marc_section AC
      GROUP BY ac.cod_arq
     ) AS ACN
WHERE ACN.author IS NOT NULL AND ACN.title IS NOT NULL;

子查询不是绝对必要的。您可以改为使用HAVING子句。

区别于不在另一台服务器的select数据库中工作

1 个答案: