8 messages in com.mysql.lists.mysqlRe: Question: how to count unique row...
FromSent OnAttachments
Kelly Yancey22 Apr 1999 08:34 
Tomislav Petrovic23 Apr 1999 02:04 
A. Brandic26 Apr 1999 04:12 
Jules Bean26 Apr 1999 06:05 
A. Brandic26 Apr 1999 06:19 
A. Brandic26 Apr 1999 06:36 
Jules Bean26 Apr 1999 06:57 
Sasha Pachev26 Apr 1999 07:49 
Subject:Re: Question: how to count unique rows in multiple tables?
From:Tomislav Petrovic (t.pe@computer.org)
Date:04/23/1999 02:04:39 AM
List:com.mysql.lists.mysql

Haven't checked this, so.........

SELECT COUNT(DISTINCT(master.id)) FROM master, a, b WHERE master.id=a.id OR master.id=b.id;

Tomy.

-----Original Message----- From: Kelly Yancey <kby@alcnet.com> To: mys@lists.mysql.com <mys@lists.mysql.com> Date: èetvrtak, travanj 22, 1999 17:23 Subject: Question: how to count unique rows in multiple tables?

I've run into a deceptively simple problem: I have 2 tables each which are associated with a 3rd table via an ID field, I need to count the number of rows with unique ID values in both of the 2 tables. For example:

Master Table ID Name -------------------------- 0 Example 1 Another example 2 One more example 3 Final example

Table A ID Data ------------------------- 0 Some associated data 0 Another piece of data 3 Yet more data

Table B ID OtherData ------------------------ 0 Stuff 1 More Stuff 1 Even More Stuff

What I would be looking for is the number of rows with unique ID values between Table A and Table B (so the answer should be 3: (IDs 0, 1, and 3)) How would I do this with a SQL query?

I really appreciate the help!

Kelly

~kby@alcnet.com~ "Silly penguin, Linux is for kids"

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