Hi, On Thu, 2006-02-02 at 23:33 -0500, Pat Collins wrote:
On Fri, 03 Feb 2006 15:17:39 +1100, Gordon Heydon <gordon@heydon.com.au> wrote :
Hi,
I have been trying to work out a small sql issue, and I was wondering if someone might be able to help me.
Basically I have 2 tables and I was to do a left join and pull out all rows which has a value in the right hand table or doesn't exist.
eg.
SELECT a.a, a.b, b.a, b.c FROM a LEFT JOIN b ON a.a = b.a WHERE b.c = 'A';
Your where clause is going to limit you to only rows where b.c = 'A'.
I thought that this was the case.
So basically I want it to return.
a b a c 1 1 null null 2 2 2 A
So you will probably want to add 'OR b.a is null' (or however you have the lack of value defined) to your WHERE above.
Yes the 'is null' fixed this for me. Thanks so much. Gordon.