# How would you know how to call this rails method (select\_all) this starting point of it's Rails API **URL:** \ **Category:** Rails\ **Created:** [October 12, 2008, 8:09am UTC](https://www.ruby-forum.com/t/how-would-you-know-how-to-call-this-rails-method-select-all-this-starting-point-of-its-rails-api/150733 "2008-10-12T08:09:40Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![greg](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/71c47a/32.png) [@greg](https://www.ruby-forum.com/u/greg)\ **Post date:** [October 12, 2008, 8:09am UTC](https://www.ruby-forum.com/t/how-would-you-know-how-to-call-this-rails-method-select-all-this-starting-point-of-its-rails-api/150733/1 "2008-10-12T08:09:40Z")
Hi, I’m curious. If you saw the Rails “select\_all(sql, name = nil)” method (rerfer [ActiveRecord::ConnectionAdapters::DatabaseStatements](http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/DatabaseStatements.html#M001060)), and wanted to use it, how would you really know how to use it and call it from this API doco? I know from googling that you can call it from within a model by going “ActiveRecord::Base.connection.select\_all(sql\_string)”, but how would I have worked this out from the API doco. Within the API page for the method it says it’s within Module “ActiveRecord::ConnectionAdapters::DatabaseStatements”. Thanks ---
**Author:** ![greg](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/71c47a/32.png) [@greg](https://www.ruby-forum.com/u/greg)\ **Post date:** [October 12, 2008, 12:00pm UTC](https://www.ruby-forum.com/t/how-would-you-know-how-to-call-this-rails-method-select-all-this-starting-point-of-its-rails-api/150733/2 "2008-10-12T12:00:42Z")
On Oct 12, 7:09 am, “Greg H.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Hi, > I’m curious. If you saw the Rails “select\_all(sql, name = nil)” method > (rerferhttp://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/Da…), > and wanted to use it, how would you really know how to use it and call > it > from this API doco? > > I know from googling that you can call it from within a model by going > “ActiveRecord::Base.connection.select\_all(sql\_string)”, but how would I have > worked this out from the API doco. That’s just me, but it seems kind of obvious to me. The second parameter is a bit more mysterious but if it has a default value chances are you can just ignore it. the fact that the first parameter is called sql strongly implies that you should give it some sql. Fred > Within the API page for the method it > says it’s within Module ---
**Author:** ![greg](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/71c47a/32.png) [@greg](https://www.ruby-forum.com/u/greg)\ **Post date:** [October 13, 2008, 12:38am UTC](https://www.ruby-forum.com/t/how-would-you-know-how-to-call-this-rails-method-select-all-this-starting-point-of-its-rails-api/150733/3 "2008-10-13T00:38:52Z")
how is it obvious to your Frederick can I ask - how would you know these methods will end up where they do - I’m guessing (but might be wrong) you would have to look through Rails code to find out how it uses/mixes in the methods as the framework instantiates itself. If I’m correct here this would be normal its not obvious to see how you would call the method… Am I on the right track here? On Sun, Oct 12, 2008 at 7:59 PM, Frederick C. \< ---
**Author:** ![greg](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/71c47a/32.png) [@greg](https://www.ruby-forum.com/u/greg)\ **Post date:** [October 13, 2008, 9:40am UTC](https://www.ruby-forum.com/t/how-would-you-know-how-to-call-this-rails-method-select-all-this-starting-point-of-its-rails-api/150733/4 "2008-10-13T09:40:40Z")
On Oct 12, 11:38 pm, “Greg H.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > how is it obvious to your Frederick can I ask - how would you know these > methods will end up where they do - I’m guessing (but might be wrong) you > would have to look through Rails code to find out how it uses/mixes in the > methods as the framework instantiates itself. If I’m correct here this > would be normal its not obvious to see how you would call the method… > Am I on the right track here? I suppose there is some prior knowledge or a bit of experimentation to know that connection adapters are split up into those various modules. Fred