arel

Where I used to do this: Foo.find_by_bar('a-value') I can now do this: Foo.where(:bar => 'a-value').limit(1).first Is this recommended? Is this the best way? Should I continue to use the "old" way because it continues to be useful syntactic sugar, or is there an Even Better way I can do that now, which will support chaining and all the other good stuff? SureshCS Rails 4 : Foo.find_by bar: 'a_value' , wibble: 'a wibble value' I think the preferable way to return a single record would be along the lines of your second example, but you can omit the limit part: Foo.where(:bar => 'a-value').first

I have several complex queries (using subqueries, etc...) and want to glue them together with OR or AND statement. For example: where1=table.where(...) where2=table.where(...) I would like something like where3=where1.or where2 Next example doesn't work for me: users.where(users[:name].eq('bob').or(users[:age].lt(25))) because of I have several where(..) queries and I want to concatenate them . In other words I have 3 methods: first return first where, second-second, third - OR concatenation. I must have able to use all 3 methods in my application and save DRY code are you looking for the form

In Rails3 there seems to be a problem when chaining two scopes (ActiveRelations) that each have a different include: Consider these two scopes, both of which work fine on their own: First scope: scope :global_only, lambda { |user| includes(:country) .where("countries.area_id <> ?", user.area) } Work.global_only(user) => (cut list of fields from SQL for legibility) SELECT * FROM "works" LEFT OUTER JOIN "countries" ON "countries"."id" = "works"."country_id" WHERE (countries.area_id <> 3) Now the second scope: scope :not_belonging_to, lambda { |user| includes(:participants) .where("participants

I have a simple model class User has_many :logs class Logs related in the usual way through the foreign key logs.user_id. I'm trying to do the following using Arel and according to the Arel doc it should work. u_t = Arel::Table::new :users l_t = Arel::Table::new :logs counts = l_t. group(l_t[:user_id]). project( l_t[:user_id].as("user_id"), l_t[:user_id].count.as("count_all") ) l_t.joins(counts).on(l_t[:id].eq(counts[:user_id])) When I do that I get the error TypeError: Cannot visit Arel::SelectManager However the author of Arel explicitly suggests that Arel can do this kind of thing. Please

I'm trying to make an attribute setter in an ActiveRecord model wrap its value in the text2ltree() postgres function before rails generates its sql query. For example, post.path = "1.2.3" post.save Should generate something like UPDATE posts SET PATH=text2ltree('1.2.3') WHERE id = 123 # or whatever What's the best way of doing this? EDIT: To achieve exactly what you are looking for above, you'd use this to override the default setter in your model file: def path=(value) self[:path] = connection.execute("SELECT text2ltree('#{value}');")[0][0] end Then the code you have above works. I'm