Re: Re: logic operands problem

Ashley Sheridan wrote:

On Mon, 2009-12-07 at 12:37 +0100, Merlin Morgenstern wrote:

Peter Ford wrote:

Merlin Morgenstern wrote:

Hello everybody, I am having trouble finding a logic for following problem: Should be true if: page = 1 OR page = 3, but it should also be true if page = 2 OR page = 3 The result should never contain 1 AND 2 in the same time. This obviously does not work: (page = 1 OR page = 3) OR (page = 2 OR page = 3) This also does not work: (page = 1 OR page = 3 AND page != 2) OR (page = 2 OR page = 3 AND page != 1) Has somebody an idea how to solve this? Thank you in advance for any help! Merlin

Surely what you need is xor (exclusive-or) I can't believe a programmer has never heard of that! (page==1 XOR page==2) AND page==3

HEllo Peter, thank you for your reply. I know about XOR, but unfortunatelly I might not know how to use it properly OR it is not aplicable on SQL. I am trying to retrive data: SELECT * FROM test WHERE ((page = 1 XOR page = 2) OR page = 3) I know this is not php, but I thought the logic should be the same in this case?! Regards, Merlin

This will likely retrieve all the records in the table. Is that what your tests have shown? Thanks, Ash http://www.ashleysheridan.co.uk

Exactly! This is unfortunatelly what happens! Any ideas how to get the correct results?