Please help : not a group by expressions

Question

not a group by expressions,
SELECT a.BATCH_ID, a.ASSOCIATE_NAME,count(a.ID)
FROM ASSOCIATE1 a,SEMESTER1 s, BATCH1 b
WHERE s.ID=b.SEMESTER_ID
AND b.ID=a.BATCH_ID
AND to_char(s.END_DATE,'DD-MON-YY')>'25-APR-13'
AND to_char(s.END_DATE,'DD-MON-YY')<'25-MAY-13'
GROUP BY a.BATCH_ID
please help :( I get this error a lot of time, I dont know what I lack about the knowledge of group by function

Answer 1

Hi,
1001317 wrote:
not a group by expressions,
SELECT a.BATCH_ID, a.ASSOCIATE_NAME,count(a.ID)
FROM ASSOCIATE1 a,SEMESTER1 s, BATCH1 b
WHERE s.ID=b.SEMESTER_ID
AND b.ID=a.BATCH_ID
AND to_char(s.END_DATE,'DD-MON-YY')>'25-APR-13'
AND to_char(s.END_DATE,'DD-MON-YY')<'25-MAY-13'
GROUP BY a.BATCH_ID
please help :( I get this error a lot of time, I dont know what I lack about the knowledge of group by functionHere are the ABC's of GROUP BY:
When you use a GROUP BY clause and/or an aggregate function, then everything in the SELECT clause must be:
(A) an <b>A</b>ggregate function,
(B) one of the "group <b>B</b>y" expressions,
(C) a <b>C</b>onstant, or
(D) something that <b>D</b>epends entirely on the above. (For example, if you "GROUP BY TRUNC(dt)", you can SELECT "TO_CHAR (TRUNC(dt), 'Mon-DD')").
In your case, the SELECT clause includes:
COUNT (a.id)     which is an aggregate (A), so it's okay,
a.batch_id     which is in the GROUP BY clause (B), so it's okay, and
a.associate_name     which is none of the above.
"GROUP BY a.batch_id" means the otput will contain 1 row for every distinct value of a.batch_id. What if there are several rows with the same value of a.batch_id: which of the several values of a.associate_name would you want to include? If your data is such that there can only be 1 distinct value of a.associate_name for each distinct value of a.batch_id, then it doesn't matter which of them is included (they are all the same), so you can use MIN (a.associate_name) or MAX (a.associate_name), or, even better, include a.associate_name in the GROUP BY clause.
I hope this answers your question.
If not, post a little sample data (CREATE TABLE and INSERT statements, relevant columns only) for all the tables involved, and the results you want from that data.
Explain, using specific examples, how you get those results from that data.
Always say what version of Oracle you're using (e.g. 11.2.0.2.0).
See the forum FAQ {message:id=9360002}
&nbps
By the way:
AND to_char(s.END_DATE,'DD-MON-YY')>'25-APR-13'
AND to_char(s.END_DATE,'DD-MON-YY')<'25-MAY-13'I don't think you really mean what you said on the 2 lines above. You porbably meant
{code
AND s.END_DATE > TO_DATE ('25-APR-2013', 'DD-Mon-YYYY')
AND s.END_DATE < TO_DATE ('25-MAY-2013', 'DD-Mon-YYYY')