I wondered the same thing (I didnt write the original query). But using 'or' will not select rows with null values as using the outer join (+) in oracle does. Hence, incorrect rows. Heres the original Oracle query: select distinct subsnp_pk, chrom, chrompos, locus, locusid, source, sourceid, a1freq, status, sampleid from subsnp, chromosome_position c, assay_validation, locus_annotation l, sample_info where subsnp_pk = c.snp_fk (+) and subsnp_pk = l.snp_fk (+) and sourceid = assayid (+) and sample_fk = sample_pk (+) and source = '10Q' order by subsnp_pk; First, I didn't write this. Second, it seems like madness to me. Oracle can somehow manage it on NT (probably due to the robust memory of the machine it was on) but it blows up MySQL on a machine with 256mb ram. No supprise with that many joins. I need to find a way to cleanly, efficiently and beautifully duplicate port this query to mysql, and would appreciate any thoughts or insights on how to do this. Thanks! -----Original Message----- From: Geoff Coffey [mailto:[EMAIL PROTECTED]] Sent: Tuesday, March 20, 2001 12:52 PM To: Bryan Coon; 'Jason Landry'; [EMAIL PROTECTED] Subject: Re: Small select question... on 3/20/01 1:20 PM, Bryan Coon at [EMAIL PROTECTED] wrote: > Sorry for the ambiguity, I was trying to make a really generic select > statement. I just meant that if 'where a = A.a' has no matches, but 'where > b = B.b' or 'where c = C.c' does match, the query returns what did match, > and just returns null where it didnt. I will look at the CASE WHEN...THEN. How is this not just: ... Where a = A.a or b = B.b or c=C.c ... Thanks, Geoff --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
