Re: index search

On Thu, Oct 23, 2008 at 10:49 PM, Robert Cummings <robert@interjinn.com> wrote: > On Thu, 2008-10-23 at 19:30 -0700, Ryan S wrote: >> Hey all, >> Was wondering how this is done, have a bunch of links like so: >> 0-9 : a : b : c -----> till Z >> >> these will be linked to the program (so far have done this) but when the user clicks any of >> those links I want to query the DB for just the first alphabet from the field "title", >> using LIKE is not working for me because its catching alphabets from the middle of the word as well. > > You're using like wrong... you want to use it with one %... > > where foo like 'a%' > >> Also how to do 0-9? do i have to have 10 if() conditions for that? > > Maybe you could add a new field to the table and set it to the first > character of the field or 0 if it's a digit. Then you can index it and > not use "like" or multiple conditions to match digits. > > Cheers, > Rob. I'm pretty sure that if your LIKE statement begins with a constant value as you have entered above, an index on the regular columns should still work. :-) As for the numeric comparison, I know MySQL has a REGEXP comparison similar to the LIKE comparator, but I don't know enough about MySQL to know if it can similarly benefit from indexes the same way. (SQL Server will let you say WHERE foo LIKE '[0-9]%', but this doesn't seem to work in MySQL.) Andrew