Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uunet!indetech!rec
From: rec@indetech.com (Rick Cobb)
Newsgroups: comp.databases
Subject: Re: How do you do this query?
Keywords: SQL, query
Message-ID: <1989Nov20.190046.12833@indetech.com>
Date: 20 Nov 89 19:00:46 GMT
References: <940@cirrus.stsci.edu>
Reply-To: rec@indetech.UUCP (Rick Cobb)
Organization: Independence Technologies, Inc. Fremont, CA
Lines: 51


You use the ``group by'' construct.  Like so, using ORACLE version 6.0:

SQL> describe abc ;				/* describe is an ORACLE
						   feature which tells you
						   about a table or view */
 Name                            Null?    Type
 ------------------------------- -------- ----
 A                                        CHAR(1)
 B                                        CHAR(1)
 C                                        NUMBER

SQL> select * from abc ;

A B          C
- - ----------
z y          2
z y          3
w y          1
w y          2
x p          1
x z          1
x z          2
x z          3

8 records selected.

SQL> select a, b, max(c) from abc group by a, b ;

A B     MAX(C)
- - ----------
w y          2
x p          1
x z          3
z y          3

SQL> select a, b, max(c) from abc where b = 'y' group by a, b ;

A B     MAX(C)
- - ----------
w y          2
z y          3

SQL> 


-- 
____*_  Rick Cobb			rcobb@indetech.uucp, sun!indetech!rcobb
\  / /  Independence Technologies	An opinion is as a drop of rain.
 \/ /   42705 Lawrence Place		That this drop fell does not mean
  \/    Fremont, CA 94538		my employers are all wet.