Inner join woes... and sweet tea!
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From: "Gary" on 5 Jul 2010 12:27 "Richard Quadling" <rquadling(a)gmail.com> wrote in message news:AANLkTinreDvFb5cJRAn9ati-iLDvzcTlkat-i7ambNcg(a)mail.gmail.com... > On 5 July 2010 14:48, Pete Ford <pete(a)justcroft.com> wrote: >>> P.S. I don't have an emu. >> >> Clearly, or you'd know that they can't fly either... >> :) > > GIGO!!! Does that mean you do have a deathwatch beetle? Gary __________ Information from ESET Smart Security, version of virus signature database 5252 (20100705) __________ The message was checked by ESET Smart Security. http://www.eset.com
From: Jason Pruim on 5 Jul 2010 13:29 On Jul 5, 2010, at 9:14 AM, Peter Lind wrote: > On 5 July 2010 15:02, Jason Pruim <lists(a)pruimphotography.com> wrote: >> Hi everyone, >> >> I'll admit right now that I'm still trying to wrestle with inner >> joins... >> Which leaves me with this code right here: >> >> <?PHP >> >> if(isset($_GET['cat'])) { >> $cat = mysql_real_escape_string($_GET['cat']); >> >> } >> >> if(isset($cat)) { >> $sql = "SELECT * FROM ".$cfgtableContent." INNER JOIN >> ".$cfgtableCategories." WHERE ".$cfgtableContent.".postCat = ". >> $cat." ORDER >> BY ".$cfgtableContent.".postNumber DESC"; >> >> } >> >> ?> >> >> Now... I know the problem is probably staring an experienced inner >> join >> master in the face and I don't even have to say it... But for those >> who >> don't know or you might be searching the archives and want to learn >> from my >> blatant misunderstanding of inner joins I'll outline said problem >> in the >> following lines. >> >> What I want to achieve: Add navigation by category to my blog. IE: >> If I want >> to display just Personal posts click on the "Personal" link and all >> other >> posts magically disappear. >> >> What I'm getting now: I have 5 categories in my blog now... I get 5 >> copies >> of each post repeated down the site all with a different category... >> >> All the variables are filled in correctly which I have checked with >> simple >> echo's. I have also tried removing the escaping of the data with no >> change >> so if possible I'd like to leave it in there as is :) >> >> I have also tried switching it from the above to this: >> >> <?PHP >> >> $sql = "SELECT * FROM ".$cfgtableContent." INNER JOIN >> ".$cfgtableContent." WHERE ".$cfgtableCategories.".postCat = ". >> $cat." ORDER >> BY ".$cfgtableContent.".postNumber DESC"; >> >> ?> >> >> with no change... >> > > There's no join clause in your query, i.e. nothing to tie the two > tables together. That will leave you with a cartesian product, i.e. > for every row in table a you'll get the entire table b joined on. You > need to specify how the tables you're joining together are related. > > Something like > > SELECT > a.row > FROM > a > JOIN b ON b.a_id = a.id > > Regards > Peter Hi Peter, Thanks for point it out... I thought I had it set right but obviously not quite... You were able to put me onto the right path and after playing with the variables I ended up with this: <?PHP if(isset($cat)) { $sql = "SELECT * FROM ".$cfgtableContent.",". $cfgtableCategories." WHERE ".$cfgtableCategories.".catID = ".$cat." AND ".$cfgtableContent.".postCat = ".$cfgtableCategories.".catID ORDER BY ".$cfgtableContent.".postNumber DESC"; } ?> Which works just fine for me! :) Joins can be some tricky stuff if you don't understand it completely...
From: Richard Quadling on 6 Jul 2010 06:00
On 5 July 2010 17:27, Gary <gpaul(a)paulgdesigns.com> wrote: > > "Richard Quadling" <rquadling(a)gmail.com> wrote in message > news:AANLkTinreDvFb5cJRAn9ati-iLDvzcTlkat-i7ambNcg(a)mail.gmail.com... >> On 5 July 2010 14:48, Pete Ford <pete(a)justcroft.com> wrote: >>>> P.S. I don't have an emu. >>> >>> Clearly, or you'd know that they can't fly either... >>> :) >> >> GIGO!!! > > > Does that mean you do have a deathwatch beetle? > > Gary No. It doesn't mean I've got a deathwatch beetle. That would be a fallacious assumption |