MySQL：选择出现多次的行
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MySQL: Select rows with more than one occurrence
提问by HyderA
Here's my query. It selects a list of ids from two tables across two databases. The query works fine.
这是我的查询。它从两个数据库的两个表中选择一个 id 列表。查询工作正常。
select en.id, fp.blogid
from french.blog_pics fp, french.blog_news fn, english.blog_news en
where fp.blogid = fn.id
and en.title_fr = fn.title
and fp.title != ''
I only want to display rows where a en.idoccurs more than once
我只想显示en.id不止一次出现的行
So for instance, if this was the current query result
例如，如果这是当前的查询结果
en.id fp.blogid
---------------
10 12
12 8
17 9
12 8
I only want to query to show this instead
我只想查询以显示此信息
en.id fp.blogid occurrences
-----------------------------
12 8 2
回答by Stefan Mai
select en.id, fp.blogid, count(*) as occurrences
from french.blog_pics fp, french.blog_news fn, english.blog_news en
where fp.blogid = fn.id
and en.title_fr = fn.title
and fp.title != ''
group by en.id
having count(*) > 1
回答by Mohamed Saligh
Use DISTINCTfor avoiding multiple occurance
使用DISTINCT避免多次数
