gistfile1.rb

params[:id] = 1

Artist.where("lastname LIKE '(?)*'",params[:id])

# This generates the following query:
# SELECT     "artists".* FROM       "artists"  WHERE     (lastname LIKE '('a')*')
# Note how you don't want the apostrophe within your "where" query ...

Artist.where("lastname LIKE ?",params[:id])

# The above generates:
# SELECT "artists".* FROM "artists" WHERE (lastname LIKE 'a')

# Now this doesn't solve your problem, but it might give you a starting point toward a solution..

Artist.where("username LIKE ?","a%")
# Might be what you're looking for?