problem with join & count - Mailing list pgsql-sql

From pat@patoche.org
Subject problem with join & count
Date
Msg-id 199902042039.VAA00553@vagabond.bde.espci.fr
Whole thread Raw
Responses Re: [SQL] problem with join & count  (jwieck@debis.com (Jan Wieck))
List pgsql-sql
Hi,

I don't succeed to build an SQL to do the task i describe below.
If someone can helps, thanks in advance.

I have two tables

number  | name
--------------
 1      | toto
 2      | titi
 3      | tutu

(here the number is a primary key)

and

number  |  tag
---------------
 1      | alpha
 1      | beta
 2      | gamma
 3      | zeta
 3      | epsilon

the number in the left column is the same of the number in the first table,
but can appear in that second table many times.

i need an sql query that will return:

name   |  how_often
-------------------
 toto  | 2
 titi  | 1
 tutu  | 2

that is, the result table should contain all names present in the first table
and then the number of times the number associated with the name appears in
the second table.

Thanks a lot for your help.

Patrick

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Patrick M.   pat@patoche.org    http://www.patoche.org/


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