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POIssue with subquery
primarykey
Id
16038485
data
AcceptedAnswerId
16038639
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1
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5
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CreationDate
2013-04-16T13:31:55.460
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0
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2013-04-16T13:40:12.027
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2013-04-16T13:40:12.027
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973578
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1928216
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0
PostTypeId
1
Score
2
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74
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text
Body
I need to run a report on the total amount of students per day. The issue I am having is that in my subquery I can not do a proper group by so that within the day I want to know how many came in for a specific reason. My query is : <pre><code>SELECT DATE_FORMAT(session.signintime, '%b %d %Y') Date, COUNT(session.session_id) 'Total', (SELECT COUNT(aidyear) FROM session WHERE aidyear = '12-13') '12-13', (SELECT COUNT(aidyear) FROM session WHERE aidyear = '13-14') '13-14' FROM session WHERE status = '3' GROUP BY Date; </code></pre> The resulting report is : <pre><code>+-------------+-------+-------+-------+ | Date | Total | 12-13 | 13-14 | +-------------+-------+-------+-------+ | Apr 15 2013 | 47 | 38 | 25 | | Apr 16 2013 | 5 | 38 | 25 | +-------------+-------+-------+-------+ 2 rows in set (0.00 sec) </code></pre> As you notice for April 16 2013 there is a total of 5 students only. Now notice that the 12-13 13-14 for both rows though are identical. When I try to do a group by within the sub query I get this error : <blockquote> <blockquote> ERROR 1241 (21000): Operand should contain 1 column(s) </blockquote> </blockquote> meaning the sub query is returning more then one row to my understanding. I tried with this query : <pre><code>SELECT DATE_FORMAT(session.signintime, '%b %d %Y') Date, COUNT(session.session_id) 'Total', (SELECT DATE_FORMAT(session.signintime, '%b %d %Y') Date, COUNT(aidyear) FROM session WHERE aidyear = '12-13' GROUP BY Date) '12-13', (SELECT DATE_FORMAT(session.signintime, '%b %d %Y') Date, COUNT(aidyear) FROM session WHERE aidyear = '13-14' GROUP BY Date) '13-14' FROM session WHERE status = '3' GROUP BY Date; </code></pre> <blockquote> <blockquote> Edit 1 As requested by Evan </blockquote> </blockquote> The table I am querying from is the session table only. I am not joining (as you noticed) The table has the following : <pre><code>Primary Key : session_id Foreign Key : anum(which is a student ID) </code></pre> Then we have: <code>why, aidyear, signintime, studentcomments, status</code> 
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<mysql><select><subquery>
Title
Issue with subquery
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1. PO
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1. This table or related slice is empty.
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1. PTQuestion
UserLastEditorUserId
1. USWhat have you tried
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1. USRixhers Ajazi
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