StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

PO
primarykey
Id
9497317
data
AcceptedAnswerId
0
AnswerCount
0
ClosedDate
CommentCount
0
CommunityOwnedDate
CreationDate
2012-02-29T10:22:42.433
FavoriteCount
0
LastActivityDate
2012-02-29T14:28:17.903
LastEditDate
2012-02-29T14:28:17.903
LastEditorUserId
231716
OwnerUserId
877581
ParentId
9497063
PostTypeId
2
Score
0
ViewCount
0
LastEditorDisplayName
text
Body
Log id is unique so you do not need to group by it - it is pointless. Also, if you use group by, you cannot take any field without aggregate function (like SUM, MIN etc). The reason is as follows: Imagine you have 3 rows: <pre><code>log_id call_date call_time agent_name agent_id customer_name nature_of_inquiry no_of_calls 3 2009-02-14 09:24:01 Lucy a3 Paul account opening 4 4 2009-02-15 09:50:01 Lucy a3 Luke account opening 2 5 2009-02-14 10:24:01 Lucy a3 jill account opening 3 </code></pre> and you type something like <pre><code>SELECT count(*), agent_name, SUM(no_of_calls), customer_name FROM table group by agent_name where agent_name="Lucy" </code></pre> what would be your expected result? Clearly there is no problem in defining what shoould be <code>count(*)</code> - it should be 3. What should be <code>agent_name</code>? The one you grouped by -- Lucy. No problems with <code>sum(no_of_calls)</code> - 4+2+3 = 9. However, here the problem begins: What should be <code>customer_name</code> ?! Paul, Luke or Jill ? you do not know this. In some database you get error if you try to do such query (for example postgresql). In MySQL I guess the first value is being returned (correct me if I am wrong). But this is not intuitive and you should avoid such queries. That is why the correct query would be: <pre><code>SELECT count(*), agent_name, SUM(no_of_calls) FROM table group by agent_name where agent_name="Lucy" </code></pre> because all fields are either in group by or are wrapped in agregate function. There might be an error in your question and you could just wanted to ask for calls to particular customers. In such case just use <code>customer_name</code> in group by, the logic remains the same. You can group by multiple values using <code>comma</code> as separator.
Tags
Title
singulars
PostAcceptedAnswerId
1. This table or related slice is empty.
PostParentId
1. POHow to get sum of counted rows
 singulars
 PostTypePostTypeId
 PTQuestion
PostTypePostTypeId
1. PTAnswer
UserLastEditorUserId
1. USBrian Mains
UserOwnerUserId
1. USmkk
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. This table or related slice is empty.
CommentsPostId
1. This table or related slice is empty.

Querying!

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.