cheat sheets.

Query#to_sql
>> User.select { |m| m.name == 'jon' }.to_sql
=> "SELECT * FROM users WHERE users.name = 'jon'"

Query#to_hash
>> User.select { |m| m.name == 'jon' }.to_hash
=> {:conditions=>"users.name = 'jon'"}

Equality

User.select { |m| m.name == 'jon' }
User.select { |m| m.name != 'jon' }
User.select { |m| m.name == 'jon' && m.age == 21 }
User.select { |m| (m.name == 'jon' || m.name == 'rick') && m.age == 21 }

Associations

User.select { |u| u.email == 'chris@ozmm.org' && u.profile.name == 'chris
wanstrath' }.map(&:title)

Comparisons

User.select { |m| m.age < 21 }.to_sql
User.select { |m| [1, 2, 3, 4].include? m.id }

LIKE and REGEXP

User.select { |m| m.name =~ 'chri%' }
User.select { |m| m.name !~ 'chris' }
User.select { |m| !(m.name =~ 'chris') }
User.select { |m| m.name =~ /chris/ }

Detect

User.detect { |m| m.name == 'chris' }

Limits

User.select { |m| m.name == 'jon' }.first
User.select { |m| m.name == 'jon' }.first(5)
User.select { |m| m.name == 'jon' }[10, 20]
User.select { |m| m.name == 'jon' }[10..20]

Sort

User.select { |m| m.name == 'jon' }.sort_by { |m| m.name }
User.select { |m| m.name == 'jon' }.sort_by { |m| [ m.name,  -m.age ] }
User.select { |m| m.name == 'jon' }.sort_by { |m| -m.profiles.title }
User.select { |m| m.name == 'jon' }.sort_by { rand }

Count

User.select { |m| m.name == 'jon' }.size

Other


User.any? { |m| m.name == 'jon' }
User.all? { |m| m.name == 'jon' }
User.select { |m| m.name == 'jon' }.empty?
User.select { |m| m.name.downcase =~ 'jon%' }.to_sql