Hi there! How can i use 2 database connections in my rails application ( if it''s possible of course ): one for reading from DB and one for writing to DB? Thanks, Dmitry -- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
Sure, try this on a model object (say called Planet): class Planet < ActiveRecord::Base establish_connection(:adapter => "mysql", :host => "mydbserver.com", :database => "myDb" .... ) end where ''...'' are the other paramters to use in the connection. This will result in the Planet model using the db connection defined above. Dmitry Hazin wrote:> Hi there! > > How can i use 2 database connections in my rails application ( if it''s > possible of course ): one for reading from DB and one for writing to DB? > > Thanks, > Dmitry > > -- > Posted via http://www.ruby-forum.com/.--~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
5MileRadius wrote:> Sure, try this on a model object (say called Planet): > > class Planet < ActiveRecord::Base > establish_connection(:adapter => "mysql", :host => "mydbserver.com", > :database => "myDb" .... ) > > end > > where ''...'' are the other paramters to use in the connection. This > will result in the Planet model using the db connection defined above.But how can I differentiate between a reader and a writer database? It seems to be rails limitation here.. -- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
On 9/21/06, Dmitry Hazin <rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> wrote:> > 5MileRadius wrote: > > Sure, try this on a model object (say called Planet): > > > > class Planet < ActiveRecord::Base > > establish_connection(:adapter => "mysql", :host => "mydbserver.com", > > :database => "myDb" .... ) > > > > end > > > > where ''...'' are the other paramters to use in the connection. This > > will result in the Planet model using the db connection defined above. > > But how can I differentiate between a reader and a writer database? It > seems to be rails limitation here..Something along the lines of pgpool <http://pgpool.projects.postgresql.org/> could be appropriate for a master/slave setup. Isak> > -- > Posted via http://www.ruby-forum.com/. > > > >--~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
these might be of help as well: http://blogs.pragprog.com/cgi-bin/pragdave.cgi/Tech/Ruby/Connections.rdoc http://wiki.rubyonrails.com/rails/pages/HowtoUseMultipleDatabases ed On 9/21/06, Isak Hansen <isak.hansen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:> > > On 9/21/06, Dmitry Hazin <rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> wrote: > > > > 5MileRadius wrote: > > > Sure, try this on a model object (say called Planet): > > > > > > class Planet < ActiveRecord::Base > > > establish_connection(:adapter => "mysql", :host => "mydbserver.com", > > > :database => "myDb" .... ) > > > > > > end > > > > > > where ''...'' are the other paramters to use in the connection. This > > > will result in the Planet model using the db connection defined above. > > > > But how can I differentiate between a reader and a writer database? It > > seems to be rails limitation here.. > > Something along the lines of pgpool > <http://pgpool.projects.postgresql.org/> could be appropriate for a > master/slave setup. > > > Isak > > > > > > -- > > Posted via http://www.ruby-forum.com/. > > > > > > > > > > >-- Ed Hickey Developer Litmus Media 816-533-0409 ehickey-A4HEbNdjHgMmlAP/+Wk3EA@public.gmane.org A Member of Think Partnership, Inc www.ThinkPartnership.com Amex ticker symbol: THK --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
On Thu, Sep 21, 2006 at 09:54:19PM +0200, Isak Hansen wrote: [...] } Something along the lines of pgpool } <http://pgpool.projects.postgresql.org/> could be appropriate for a } master/slave setup. I like PostgreSQL and would like to use it, but I have to do my due diligence in looking for similar solutions on top of our current RDBMS (MySQL) and, potentially, any commercial databases. The pgpool solution (or, rather, pgpool-II) looks great in that both read/write partitioning and vertical (row) partitioning is completely transparent to the application layer. Does anyone know of anything like that, commercial or otherwise, exist for MySQL or the various commercial RDBMSs? } Isak --Greg --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
Is there a way to maintain two open connections simultaneously using
ActiveRecord::Base?
for example, in a generic script with ''dbi'' or something, I
could
establish two connections as such:
class Something
def test
dbh1 = DBI.connect("dbi:Mysql:test:system1",
"user", "pass")
dbh2 = DBI.connect("dbi:Oracle:test:system2",
"user", "pass")
accounts = {
"system1" => dbh1.distinct("users from
users"),
"system2" => dbh2.distinct("usernames from
user_acc")
}
dbh1.disconnect
dbh2.disconnect
return accounts
end
end
This is bs code but, can two activerecord::base connections be
established simultaneously like this?
On 9/22/06, Gregory Seidman
<gsslist+ror-dNXPQ6k9rNiG6BJUYyje5axOck334EZe@public.gmane.org>
wrote:>
> On Thu, Sep 21, 2006 at 09:54:19PM +0200, Isak Hansen wrote:
> [...]
> } Something along the lines of pgpool
> } <http://pgpool.projects.postgresql.org/> could be appropriate for a
> } master/slave setup.
>
> I like PostgreSQL and would like to use it, but I have to do my due
> diligence in looking for similar solutions on top of our current RDBMS
> (MySQL) and, potentially, any commercial databases.
>
> The pgpool solution (or, rather, pgpool-II) looks great in that both
> read/write partitioning and vertical (row) partitioning is completely
> transparent to the application layer. Does anyone know of anything like
> that, commercial or otherwise, exist for MySQL or the various commercial
> RDBMSs?
>
> } Isak
> --Greg
>
>
> >
>
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On 9/22/06, x1 <caldridge-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:> > > Is there a way to maintain two open connections simultaneously using > ActiveRecord::Base?There are no issues at all with establishing as many connections as you wish. This issue lies more with linking them to a model more then making the connection. What is below is an example - stolen blatantly from earlier in the thread........ class Planet < ActiveRecord::Base establish_connection(:adapter => "mysql", :host => "mydbserver.com", :database => "myDb" .... ) end To do what you want below - I might be tempted to have a base model for users and then create at least one subclass that had look like class DBxUser < User establish_connection.......................(to DBx) end Then from your controller create both a User and a DBxUser and then make you concatenated array by calling into both of them. I''m assuming that at least one of the two database connections is the standard connection you use for the rest of your connection (i.e. the one listed under config/database.yml). John W Higgins wishdev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
this has been discussed numerous times on the list and is documented here as well: http://wiki.rubyonrails.org/rails/pages/HowtoUseMultipleDatabases http://wiki.rubyonrails.org/rails/pages/HowtoSwitchBetweenMultipleDevelopmentDatabases http://wiki.rubyonrails.org/rails/pages/HowtoUseMultipleDatabasesOnePerTable ed On 9/22/06, John Higgins <wishdev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:> > On 9/22/06, x1 <caldridge-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote: > > > > > > Is there a way to maintain two open connections simultaneously using > > ActiveRecord::Base? > > > There are no issues at all with establishing as many connections as you > wish. This issue lies more with linking them to a model more then making the > connection. > > What is below is an example - stolen blatantly from earlier in the > thread........ > > class Planet < ActiveRecord::Base > establish_connection(:adapter => "mysql", :host => "mydbserver.com", > :database => "myDb" .... ) > end > > To do what you want below - I might be tempted to have a base model for > users and then create at least one subclass that had look like > > class DBxUser < User > establish_connection.......................(to DBx) > end > > Then from your controller create both a User and a DBxUser and then make > you concatenated array by calling into both of them. I''m assuming that at > least one of the two database connections is the standard connection you use > for the rest of your connection (i.e. the one listed under > config/database.yml). > > John W Higgins > wishdev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org > > > > > >-- Ed Hickey Developer Litmus Media 816-533-0409 ehickey-A4HEbNdjHgMmlAP/+Wk3EA@public.gmane.org A Member of Think Partnership, Inc www.ThinkPartnership.com Amex ticker symbol: THK --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
Anyway, all these methods seem to be a little tricky, like workarounds I think. Maybe something like mysql pool could be more ''correct'' solution -- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
Dmitry Hazin wrote:> Anyway, all these methods seem to be a little tricky, like workarounds I > think. > Maybe something like mysql pool could be more ''correct'' solutionI don''t think so ... I hope not ! I don''t really like to see a "pool" solution like the pg-one on my DB (it''s neither PGSql, nor MySQL). But all the answers given are right. And just before saying Rails lake something, ask yourself about what you really want to do and how to do it the right way. If you want a read/write access restriction in Rails, so you have the answer : 2 connections and in one abstract connection you undefine all the write methods. If you want read/write access on database basis, then choose a database that could deal with this, or write an Adapter with those functionnalities. Rails-like systems are complex because of many layers. When you have a problem, try to find the good layer to deal with to solve this problem. It''s not already easy to find it at first ;) Tony -- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---