MetaWhere to Squeel migration

Question

In MetaWhere I combined conditions to sql variable using loops, if else statements.

sql = {}
email_starts_with = "vany%"
sql["growth"] = 0..200
sql = sql & (:rating > 50)
sql = sql & (:email =~ email_starts_with)
.....
.....
User.where(sql).to_sql
=> "SELECT \"users\".* FROM \"users\" WHERE \"users\".\"growth\" BETWEEN 0 AND 200 AND    \"users\".\"rating\" > 50 AND \"users\".\"email\" ILIKE 'vany%'"
user = User.where(sql).first
=> #<User id: 1, .................................. >

How can I do the same using Squeel?

Thanks for any help)

Answer 1

I resolved my problem using Arel. I think (I just changed MetaWhere code to Arel) that it is just the same as MetaWhere.

t = User.arel_table

email_starts_with = "vany%"
sql = t[:rating].gt(50)
sql = t[:growth].in(0..200)
sql = sql.and(t[:email].matches(email_starts_with))

User.where(sql).to_sql
=> "SELECT \"users\".* FROM \"users\"  WHERE (\"users\".\"growth\" BETWEEN 0 AND 200 AND \"users\".\"email\" ILIKE 'vany%')"

Thanks everybody for help!

Answer 2

check out the "squeel" method, new in 0.9.0. It was added to support exactly this sort of thing. It just gives you an easy way to write a block of Squeel DSL without actually attaching it to a "where", "join", etc.

You also might want to consider encapsulating this logic in a sifter for your model.

class User < ActiveRecord::Base
  sifter :my_sifter do |growth_range, min_rating, email_start|
    growth.in(growth_range) & rating.gt(min_rating) & email.matches("#{email_start}%")
  end
end

User.where{sift :my_sifter, 0..200, 50, 'vany'}