在另一台服务器的选择数据库中不同的工作

Question

我在这里有这个选择：

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

我测试了一些从 serverOne 到 serverTwo 的 sql，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“serverTwo”上运行它，上面的这个 sql 就可以正常工作（意味着 sintaxe 是正确的），但如果我从 serverOne 运行它就不行。但是，如果我删除 DISTINCT 关键字，它就可以工作（显示重复的行，但可以）。

这个 DISTINCT 会发生什么？也许是一些 COLLATE 冲突？

Answer 1

我认为您只需要条件聚合：

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。您可以改用HAVING 子句。