Solved

GROUP BY question

Posted on 2014-11-19
2
113 Views
Last Modified: 2014-11-19
Hello, I must "build" a "top-ten" of loans in a library querying all the loans registered in an oracle database.
I've found the right query to do:

select Z30_REC_KEY, Z30_NO_LOANS from z30 left join z36h on z36h_rec_key = z30_rec_key where Z36H_SUB_LIBRARY  = 'COLUG' AND Z36H_LOAN_DATE BETWEEN 20120401 AND 20141113
GROUP BY z36h_rec_key

but the result has multiple entries of the same type. here follows an example of the first rows:

000222514                              26
000222514                              26
000222514                              26
000168117                              21
000168117                              21

(say..the book 000222514 has 26 loans, the book 000168117 21 loans...)
I'd like to obtain instead only one entry for each record, i.e.:
000222514                              26
000168117                              21

I suppose I must use a GROUP BY, but if I group by Z30_REC_KEY I obtain the following error:

select Z30_REC_KEY, Z30_NO_LOANS from z30 left join z36h on z36h_rec_key = z30_rec_key where Z36H_SUB_LIBRARY  = 'COLUG' AND Z36H_LOAN_DATE BETWEEN 20120401 AND 20141113
GROUP BY Z30_REC_KEY

ERROR at line 1:
ORA-00979: not a GROUP BY expression

can you help me?
thanks
fabiano
0
Comment
Question by:fabianope65
2 Comments
 
LVL 24

Accepted Solution

by:
Phillip Burton earned 500 total points
ID: 40451974
Use Select Distinct instead:

select distinct Z30_REC_KEY, Z30_NO_LOANS from z30 
left join z36h on z36h_rec_key = z30_rec_key 
where Z36H_SUB_LIBRARY  = 'COLUG' AND Z36H_LOAN_DATE BETWEEN 20120401 AND 20141113

Open in new window

0
 

Author Closing Comment

by:fabianope65
ID: 40451995
it works perfectly, thanks!! :=))
fabiano
0

Featured Post

Resolve Critical IT Incidents Fast

If your data, services or processes become compromised, your organization can suffer damage in just minutes and how fast you communicate during a major IT incident is everything. Learn how to immediately identify incidents & best practices to resolve them quickly and effectively.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

'Between' is such a common word we rarely think about it but in SQL it has a very specific definition we should be aware of. While most database vendors will have their own unique phrases to describe it (see references at end) the concept in common …
PL/SQL can be a very powerful tool for working directly with database tables. Being able to loop will allow you to perform more complex operations, but can be a little tricky to write correctly. This article will provide examples of basic loops alon…
Via a live example show how to connect to RMAN, make basic configuration settings changes and then take a backup of a demo database
This videos aims to give the viewer a basic demonstration of how a user can query current session information by using the SYS_CONTEXT function

749 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question