StackOverflow2013

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plurals

PO
primarykey
Id
14553580
data
AcceptedAnswerId
0
AnswerCount
0
ClosedDate
CommentCount
1
CommunityOwnedDate
CreationDate
2013-01-27T23:37:53.557
FavoriteCount
0
LastActivityDate
2013-01-28T00:23:42.310
LastEditDate
2013-01-28T00:23:42.310
LastEditorUserId
2012737
OwnerUserId
2012737
ParentId
14553233
PostTypeId
2
Score
2
ViewCount
0
LastEditorDisplayName
text
Body
It's pretty easy if you don't do the sorting by most countries in common (you could do it in code later if the result sets won't be too large): <pre class="lang-sql prettyprint-override"><code>SELECT o.id userid, u_cs.countryid FROM users u JOIN countryselection u_cs ON (u.id = u_cs.userid) JOIN countryselection o_cs ON (u_cs.countryid = o_cs.countryid) JOIN users o ON (o_cs.userid = o.id) WHERE u.id = :userid AND -- The user we want u.id <> o.id AND -- Exclude ourselves ( -- Check whether the other person is -- compatible with us (u.pref_m = 1 AND o.gender = 'male') OR (u.pref_f = 1 AND o.gender = 'female') ) AND ( -- Check whether we're compatible with the -- other person (o.pref_m = 1 AND u.gender = 'male') OR (o.pref_f = 1 AND u.gender = 'female') ) </code></pre> <a href="http://sqlfiddle.com/#!2/5ee7c/23" rel="nofollow">SQL Fiddle</a> <hr> If you do want the sorting, I think the best option is to use <code>GROUP_CONCAT</code> (because MySQL sucks and doesn't support windowing/analytic functions). <pre class="lang-sql prettyprint-override"><code>SELECT o.id userid, GROUP_CONCAT(u_cs.countryid) countries FROM users u JOIN countryselection u_cs ON (u.id = u_cs.userid) JOIN countryselection o_cs ON (u_cs.countryid = o_cs.countryid) JOIN users o ON (o_cs.userid = o.id) WHERE u.id = :userid AND -- The user we want u.id <> o.id AND -- Exclude ourselves ( -- Check whether the other person is -- compatible with us (u.pref_m = 1 AND o.gender = 'male') OR (u.pref_f = 1 AND o.gender = 'female') ) AND ( -- Check whether we're compatible with the -- other person (o.pref_m = 1 AND u.gender = 'male') OR (o.pref_f = 1 AND u.gender = 'female') ) GROUP BY o.id ORDER BY COUNT(u_cs.countryid) DESC </code></pre> You could probably pull this off with some nasty subqueries too, but I get the feeling it'll kill performance. <a href="http://sqlfiddle.com/#!2/5ee7c/22" rel="nofollow">SQL Fiddle</a>
Tags
Title
singulars
PostAcceptedAnswerId
1. This table or related slice is empty.
PostParentId
1. POSQL statement I can't wrap my head around (brain too small)
 singulars
 PostTypePostTypeId
 PTQuestion
PostTypePostTypeId
1. PTAnswer
UserLastEditorUserId
1. USimpl
UserOwnerUserId
1. USimpl
plurals
PostLinksPostIdRelatedPostId
1. This table or related slice is empty.
PostLinksRelatedPostIdPostId
1. This table or related slice is empty.
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. This table or related slice is empty.
VotesPostIdCreationDate
1. VO
 singulars
 PostPostId
 PO
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
2. VO
 singulars
 PostPostId
 PO
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
CommentsPostId
1. CO+1 i missed the fact to check is second person compatible with us (already fixed)
 singulars
 PostPostId
 PO
 UserUserId
 USPeter

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