Reportico / Sql联合查询

Question

使用Union时，我遇到了查询问题。

我使用以下查询来获取结果：

SELECT substr(directory_vis,locate(":", directory_vis) +1, (locate(">>", directory_vis) - locate(":", directory_vis) -1)) as dossier, count(doc_id) as aantal_documenten
FROM openims_algemeen_document_data
WHERE 1=1
GROUP BY dossier

UNION 

SELECT substr(directory_vis,locate(":", directory_vis) +1, (locate(">>", directory_vis) - locate(":", directory_vis) -1)) as dossier, count(doc_id) as aantal_documenten
FROM postin_document_data
WHERE 1=1
GROUP BY dossier

UNION

SELECT substr(directory_vis,locate(":", directory_vis) +1, (locate(">>", directory_vis) - locate(":", directory_vis) -1)) as dossier, count(doc_id) as aantal_documenten
FROM qualdoc_document_data
WHERE 1=1
GROUP BY dossier
ORDER BY dossier

我需要拥有所有＆＃34;档案＆＃34;来自多个表。我在这里遇到的问题是我得到了重复的记录。因为同样的＆＃34;档案＆＃34;可以在多个表中。

我该如何解决这个问题？