Christian Hammers wrote:
>
> On Thu, Mar 08, 2001 at 10:29:20AM -0700, Steve Ruby wrote:
> > He is doing an inner join, you are doing a left join, they (potentialy)
> > do not produce the same results.
> Hmm have to think about it... inner means fields where the right table has
> a NULL value in the condition are left out, right?
>
> > If you have 5 hour selects you are probably missing some vital indexes, or
> > you are using a long of like '%blah' or "OR"
> ... or using 1.5GB big tables...
>
> thanks,
>
> -christian-
See the manual... I think you have them backwards, left join means
that lines from 'a' without corresponding lines in 'b' WILL be shown
with NULL
Inner join (commas) means you will only get lines where there exists
a b.id corresponding to every a.id
1.5 GB tables to not produce 5 hour selects unless you are lacking
indexes or using OR or '%like' or other criteria that doesn't use indexes
in mysql.
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