Design.where("
business_name IS NULL ||
business_name = ''")
Design.where("business_name IS NULL or CAST(business_name as text) = ''")
Design.where(:business_name => '')
Design.where.not(:business_name => '')
Design.where.not("business_name IS NULL or CAST(business_name as text) = ''")
Address.where(["city != ?", "London"])