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plurals

POGet "latest" row after GROUP BY over multiple tables
primarykey
Id
13627114
data
AcceptedAnswerId
13629442
AnswerCount
2
ClosedDate
CommentCount
3
CommunityOwnedDate
CreationDate
2012-11-29T13:41:02.660
FavoriteCount
0
LastActivityDate
2012-11-29T18:06:05.943
LastEditDate
2012-11-29T18:01:36.140
LastEditorUserId
939860
OwnerUserId
1127025
ParentId
0
PostTypeId
1
Score
1
ViewCount
302
LastEditorDisplayName
text
Body
I'd preferably like to first query listed below and just group by <code>stories.id</code>, but I get the following error: <code>ERROR: column "u.first_name" must appear in the GROUP BY clause or be used in an aggregate function LINE 1: SELECT "s".*, "u"."first_name", "u"."last_name", ("i"."filen...</code> The second query works but does not group by <code>stories.id</code> and generates the wrong results. Is it possible to select from multiple tables and not group by all of them? The table <code>panels</code> also has a column <code>updated_at</code>. I would like to get the newest <code>file</code> per story according to <code>panels.updated_at</code>. <pre><code> SELECT "s".*, "u"."first_name", "u"."last_name", ("i"."filename" || '.' || "i"."extension") AS "file" FROM "stories" "s" LEFT JOIN "panels" "p" ON("p"."story_id" = "s"."id") LEFT JOIN "users" "u" ON("s"."user_id" = "u"."uid") LEFT JOIN "images" "i" ON ("p"."image_id" = "i"."id") WHERE "s"."complete" = false AND "s"."created_by" = 205700489 GROUP BY "s"."id", ORDER BY "s"."created_at" DESC </code></pre> <hr> <pre><code> SELECT "s".*, "u"."first_name", "u"."last_name", ("i"."filename" || '.' || "i"."extension") AS "file" FROM "stories" "s" LEFT JOIN "panels" "p" ON("p"."story_id" = "s"."id") LEFT JOIN "users" "u" ON("s"."user_id" = "u"."uid") LEFT JOIN "images" "i" ON ("p"."image_id" = "i"."id") WHERE "s"."complete" = false AND "s"."created_by" = 205700489 GROUP BY "s"."id", "u"."first_name", "u"."last_name", "i"."filename", "i"."extension" ORDER BY "s"."created_at" DESC </code></pre>
Tags
<sql><postgresql><greatest-n-per-group><postgresql-9.1><rails-postgresql>
Title
Get "latest" row after GROUP BY over multiple tables
singulars
PostAcceptedAnswerId
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
PostParentId
1. This table or related slice is empty.
PostTypePostTypeId
1. PTQuestion
UserLastEditorUserId
1. USErwin Brandstetter
UserOwnerUserId
1. USStefan
plurals
PostLinksPostIdRelatedPostId
1. PL
 singulars
 LinkTypeLinkTypeId
 LTLinked
PostLinksRelatedPostIdPostId
1. This table or related slice is empty.
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
2. PO
 singulars
 PostTypePostTypeId
 PTAnswer
VotesPostIdCreationDate
1. VO
 singulars
 PostPostId
 POGet "latest" row after GROUP BY over multiple tables
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
CommentsPostId

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Guidance

A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.