increment feature is not working

Hello

i have a custom query which is getting max number from one of column.
I want to get that number increment by 1 and then save that in
different table. please refer following code:

def getmaxphasenumber(templaid)
   self.find_by_sql("select max(templateid) from templates")
end

maxnumber = Templatephases.getmaxphasenumber(templateid)

if !maxnumber.blank?
     tmpnumber = maxnumber + 1
else
    tmpnumber = 1
end

tmpnumber is returning an error. i tried maxnumber.to_i didnt work.

Please advice

thanks

Ajit

can't convert Fixnum into Array.. this is the error message i am
getting

Thanks my friend.... i was doing it wrong way.... dropped the idea of
custom query... used Templatephase.maximum and it worked

thanks a ton

Ajit