Hi, I wish to know, how those class work exactly, where can I find the documentation? or can someone explain to me how a connection is made via those class??? Thanks you very much!!!! Saiho __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
The connection adapters know how to connect to their respective database servers. In the config/database.yml file you specify which adapter (i.e. which database server) you want to use, and also provide necessary parameters such as host, username, password. These parameters vary by adapter. Thus, you don''t have to make an explicit connection to the database in your rails application. Rails will connect to the database using the information you provided in config/database.yml see http://api.rubyonrails.org for more details. Choose ActiveRecord::ConnectionAdapters::WhateverAdapterYouNeedToUse for adapter-specific details. -Derrick Spell On Jan 25, 2006, at 10:03 AM, Saiho Yuen wrote:> Hi, > > I wish to know, how those class work exactly, where > can I find the documentation? or can someone explain > to me how a connection is made via those class??? > > Thanks you very much!!!! > > Saiho > > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails >
Hi, Thanks you very much foir the information:) Do you know who is the writter of these classes? I have some question for him (or her) Saiho --- Derrick Spell <derrickspell@cdmplus.com> wrote:> The connection adapters know how to connect to their > respective > database servers. In the config/database.yml file > you specify which > adapter (i.e. which database server) you want to > use, and also > provide necessary parameters such as host, username, > password. These > parameters vary by adapter. > > Thus, you don''t have to make an explicit connection > to the database > in your rails application. Rails will connect to > the database using > the information you provided in config/database.yml > > see http://api.rubyonrails.org for more details. > Choose >ActiveRecord::ConnectionAdapters::WhateverAdapterYouNeedToUse> for > adapter-specific details. > > > -Derrick Spell > > On Jan 25, 2006, at 10:03 AM, Saiho Yuen wrote: > > > Hi, > > > > I wish to know, how those class work exactly, > where > > can I find the documentation? or can someone > explain > > to me how a connection is made via those class??? > > > > Thanks you very much!!!! > > > > Saiho > > > > > > __________________________________________________ > > Do You Yahoo!? > > Tired of spam? Yahoo! Mail has the best spam > protection around > > http://mail.yahoo.com > > _______________________________________________ > > Rails mailing list > > Rails@lists.rubyonrails.org > > > http://lists.rubyonrails.org/mailman/listinfo/rails > > > > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails >If God really exists, I would like to know what the dinosaurs have done to deserve their extinction. Water is unknown to fishes, until they discover air. http://www.geocities.com/sayoyo/ __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
Well, as far as i know the adapters were written by all different people. For instance, I just finished writing one for OpenBase which is sitting in the patch queue right now (ticket #3538). I suppose your best bet is to post your questions to this list, and possibly to the rails-core list and hope the author is listening :) You might also try asking around on IRC for the author of a specific adapter. -Derrick On Jan 25, 2006, at 11:18 AM, Saiho Yuen wrote:> Hi, > > Thanks you very much foir the information:) Do you > know who is the writter of these classes? I have some > question for him (or her) > > Saiho > > > > --- Derrick Spell <derrickspell@cdmplus.com> wrote: > >> The connection adapters know how to connect to their >> respective >> database servers. In the config/database.yml file >> you specify which >> adapter (i.e. which database server) you want to >> use, and also >> provide necessary parameters such as host, username, >> password. These >> parameters vary by adapter. >> >> Thus, you don''t have to make an explicit connection >> to the database >> in your rails application. Rails will connect to >> the database using >> the information you provided in config/database.yml >> >> see http://api.rubyonrails.org for more details. >> Choose >> > ActiveRecord::ConnectionAdapters::WhateverAdapterYouNeedToUse >> for >> adapter-specific details. >> >> >> -Derrick Spell >> >> On Jan 25, 2006, at 10:03 AM, Saiho Yuen wrote: >> >>> Hi, >>> >>> I wish to know, how those class work exactly, >> where >>> can I find the documentation? or can someone >> explain >>> to me how a connection is made via those class??? >>> >>> Thanks you very much!!!! >>> >>> Saiho >>> >>> >>> __________________________________________________ >>> Do You Yahoo!? >>> Tired of spam? Yahoo! Mail has the best spam >> protection around >>> http://mail.yahoo.com >>> _______________________________________________ >>> Rails mailing list >>> Rails@lists.rubyonrails.org >>> >> http://lists.rubyonrails.org/mailman/listinfo/rails >>> >> >> _______________________________________________ >> Rails mailing list >> Rails@lists.rubyonrails.org >> http://lists.rubyonrails.org/mailman/listinfo/rails >> > > > If God really exists, I would like to > know what the dinosaurs have done to > deserve their extinction. > > Water is unknown to fishes, > until they discover air. > > http://www.geocities.com/sayoyo/ > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails >
Hi, Derrick We are trying to connect to two diffferents database within the same action. However, we doesn''t success, because we can''t disconnect the first connection. after some modification of the connection_specification and the adapter, we are able to "clear up" part of the connection. But each time we try to connect to a new databse, Ruby-rails always give us back the same adapter with the first connection. Do you know how to stop proper a connection???? we have clean up @@defined_connections and @@active_connections, with "clear", since those ara instance of hash. But rails keep giving us back the old adapter. Do you know why? Thanks you very much for your help Saiho --- Derrick Spell <derrickspell@cdmplus.com> wrote:> Well, as far as i know the adapters were written by > all different > people. For instance, I just finished writing one > for OpenBase which > is sitting in the patch queue right now (ticket > #3538). > > I suppose your best bet is to post your questions to > this list, and > possibly to the rails-core list and hope the author > is listening :) > You might also try asking around on IRC for the > author of a specific > adapter. > > -Derrick > > > On Jan 25, 2006, at 11:18 AM, Saiho Yuen wrote: > > > Hi, > > > > Thanks you very much foir the information:) Do you > > know who is the writter of these classes? I have > some > > question for him (or her) > > > > Saiho > > > > > > > > --- Derrick Spell <derrickspell@cdmplus.com> > wrote: > > > >> The connection adapters know how to connect to > their > >> respective > >> database servers. In the config/database.yml > file > >> you specify which > >> adapter (i.e. which database server) you want to > >> use, and also > >> provide necessary parameters such as host, > username, > >> password. These > >> parameters vary by adapter. > >> > >> Thus, you don''t have to make an explicit > connection > >> to the database > >> in your rails application. Rails will connect to > >> the database using > >> the information you provided in > config/database.yml > >> > >> see http://api.rubyonrails.org for more details. > >> Choose > >> > > >ActiveRecord::ConnectionAdapters::WhateverAdapterYouNeedToUse> >> for > >> adapter-specific details. > >> > >> > >> -Derrick Spell > >> > >> On Jan 25, 2006, at 10:03 AM, Saiho Yuen wrote: > >> > >>> Hi, > >>> > >>> I wish to know, how those class work exactly, > >> where > >>> can I find the documentation? or can someone > >> explain > >>> to me how a connection is made via those > class??? > >>> > >>> Thanks you very much!!!! > >>> > >>> Saiho > >>> > >>> > >>> > __________________________________________________ > >>> Do You Yahoo!? > >>> Tired of spam? Yahoo! Mail has the best spam > >> protection around > >>> http://mail.yahoo.com > >>> _______________________________________________ > >>> Rails mailing list > >>> Rails@lists.rubyonrails.org > >>> > >> > http://lists.rubyonrails.org/mailman/listinfo/rails > >>> > >> > >> _______________________________________________ > >> Rails mailing list > >> Rails@lists.rubyonrails.org > >> > http://lists.rubyonrails.org/mailman/listinfo/rails > >> > > > > > > If God really exists, I would like to > > know what the dinosaurs have done to > > deserve their extinction. > > > > Water is unknown to fishes, > > until they discover air. > > > > http://www.geocities.com/sayoyo/ > > > > __________________________________________________ > > Do You Yahoo!? > > Tired of spam? Yahoo! Mail has the best spam > protection around > > http://mail.yahoo.com > > _______________________________________________ > > Rails mailing list > > Rails@lists.rubyonrails.org > > > http://lists.rubyonrails.org/mailman/listinfo/rails > > > > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails >__________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
I''m certainly no expert at this, as I''ve not even tried it myself. However, I do know that you can specify a class-specific database connection. Using this feature, I assume you could create two models, say MyDataInPostgreSQL and MyDataInMySQL. Then, you could use these two models in the same controller action and each model would be creating it''s own class-specific connection to the database. Exactly how to do it? I have no idea (sorry)....any experts out there? -Derrick On Jan 25, 2006, at 1:14 PM, Saiho Yuen wrote:> Hi, Derrick > > We are trying to connect to two diffferents database > within the same action. However, we doesn''t success, > because we can''t disconnect the first connection. > after some modification of the > connection_specification and the adapter, we are able > to "clear up" part of the connection. But each time we > try to connect to a new databse, Ruby-rails always > give us back the same adapter with the first > connection. Do you know how to stop proper a > connection???? > > we have clean up @@defined_connections and > @@active_connections, with "clear", since those ara > instance of hash. But rails keep giving us back the > old adapter. > > Do you know why? > > > Thanks you very much for your help > > Saiho > > > > > --- Derrick Spell <derrickspell@cdmplus.com> wrote: > >> Well, as far as i know the adapters were written by >> all different >> people. For instance, I just finished writing one >> for OpenBase which >> is sitting in the patch queue right now (ticket >> #3538). >> >> I suppose your best bet is to post your questions to >> this list, and >> possibly to the rails-core list and hope the author >> is listening :) >> You might also try asking around on IRC for the >> author of a specific >> adapter. >> >> -Derrick >> >> >> On Jan 25, 2006, at 11:18 AM, Saiho Yuen wrote: >> >>> Hi, >>> >>> Thanks you very much foir the information:) Do you >>> know who is the writter of these classes? I have >> some >>> question for him (or her) >>> >>> Saiho >>> >>> >>> >>> --- Derrick Spell <derrickspell@cdmplus.com> >> wrote: >>> >>>> The connection adapters know how to connect to >> their >>>> respective >>>> database servers. In the config/database.yml >> file >>>> you specify which >>>> adapter (i.e. which database server) you want to >>>> use, and also >>>> provide necessary parameters such as host, >> username, >>>> password. These >>>> parameters vary by adapter. >>>> >>>> Thus, you don''t have to make an explicit >> connection >>>> to the database >>>> in your rails application. Rails will connect to >>>> the database using >>>> the information you provided in >> config/database.yml >>>> >>>> see http://api.rubyonrails.org for more details. >>>> Choose >>>> >>> >> > ActiveRecord::ConnectionAdapters::WhateverAdapterYouNeedToUse >>>> for >>>> adapter-specific details. >>>> >>>> >>>> -Derrick Spell >>>> >>>> On Jan 25, 2006, at 10:03 AM, Saiho Yuen wrote: >>>> >>>>> Hi, >>>>> >>>>> I wish to know, how those class work exactly, >>>> where >>>>> can I find the documentation? or can someone >>>> explain >>>>> to me how a connection is made via those >> class??? >>>>> >>>>> Thanks you very much!!!! >>>>> >>>>> Saiho >>>>> >>>>> >>>>> >> __________________________________________________ >>>>> Do You Yahoo!? >>>>> Tired of spam? Yahoo! Mail has the best spam >>>> protection around >>>>> http://mail.yahoo.com >>>>> _______________________________________________ >>>>> Rails mailing list >>>>> Rails@lists.rubyonrails.org >>>>> >>>> >> http://lists.rubyonrails.org/mailman/listinfo/rails >>>>> >>>> >>>> _______________________________________________ >>>> Rails mailing list >>>> Rails@lists.rubyonrails.org >>>> >> http://lists.rubyonrails.org/mailman/listinfo/rails >>>> >>> >>> >>> If God really exists, I would like to >>> know what the dinosaurs have done to >>> deserve their extinction. >>> >>> Water is unknown to fishes, >>> until they discover air. >>> >>> http://www.geocities.com/sayoyo/ >>> >>> __________________________________________________ >>> Do You Yahoo!? >>> Tired of spam? Yahoo! Mail has the best spam >> protection around >>> http://mail.yahoo.com >>> _______________________________________________ >>> Rails mailing list >>> Rails@lists.rubyonrails.org >>> >> http://lists.rubyonrails.org/mailman/listinfo/rails >>> >> >> _______________________________________________ >> Rails mailing list >> Rails@lists.rubyonrails.org >> http://lists.rubyonrails.org/mailman/listinfo/rails >> > > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails >
I was just looking at the ActiveRecord::Base api. It looks like to implement this you just need to overload the establish_connection method in your model. If you don''t have this method in your model, then the version in ActiveRecord::Base is used, which will connect to the database in your config/database.yml file. By placing a method named establish_connection in your model, you can have just that model and it''s children use another database. Hope that helps. -Derrick Spell On Jan 25, 2006, at 3:57 PM, Derrick Spell wrote:> I''m certainly no expert at this, as I''ve not even tried it myself. > However, I do know that you can specify a class-specific database > connection. Using this feature, I assume you could create two > models, say MyDataInPostgreSQL and MyDataInMySQL. Then, you could > use these two models in the same controller action and each model > would be creating it''s own class-specific connection to the database. > > Exactly how to do it? I have no idea (sorry)....any experts out > there? > > -Derrick > > > On Jan 25, 2006, at 1:14 PM, Saiho Yuen wrote: > >> Hi, Derrick >> >> We are trying to connect to two diffferents database >> within the same action. However, we doesn''t success, >> because we can''t disconnect the first connection. >> after some modification of the >> connection_specification and the adapter, we are able >> to "clear up" part of the connection. But each time we >> try to connect to a new databse, Ruby-rails always >> give us back the same adapter with the first >> connection. Do you know how to stop proper a >> connection???? >> >> we have clean up @@defined_connections and >> @@active_connections, with "clear", since those ara >> instance of hash. But rails keep giving us back the >> old adapter. >> >> Do you know why? >> >> >> Thanks you very much for your help >> >> Saiho >> >> >> >> >> --- Derrick Spell <derrickspell@cdmplus.com> wrote: >> >>> Well, as far as i know the adapters were written by >>> all different >>> people. For instance, I just finished writing one >>> for OpenBase which >>> is sitting in the patch queue right now (ticket >>> #3538). >>> >>> I suppose your best bet is to post your questions to >>> this list, and >>> possibly to the rails-core list and hope the author >>> is listening :) >>> You might also try asking around on IRC for the >>> author of a specific >>> adapter. >>> >>> -Derrick >>> >>> >>> On Jan 25, 2006, at 11:18 AM, Saiho Yuen wrote: >>> >>>> Hi, >>>> >>>> Thanks you very much foir the information:) Do you >>>> know who is the writter of these classes? I have >>> some >>>> question for him (or her) >>>> >>>> Saiho >>>> >>>> >>>> >>>> --- Derrick Spell <derrickspell@cdmplus.com> >>> wrote: >>>> >>>>> The connection adapters know how to connect to >>> their >>>>> respective >>>>> database servers. In the config/database.yml >>> file >>>>> you specify which >>>>> adapter (i.e. which database server) you want to >>>>> use, and also >>>>> provide necessary parameters such as host, >>> username, >>>>> password. These >>>>> parameters vary by adapter. >>>>> >>>>> Thus, you don''t have to make an explicit >>> connection >>>>> to the database >>>>> in your rails application. Rails will connect to >>>>> the database using >>>>> the information you provided in >>> config/database.yml >>>>> >>>>> see http://api.rubyonrails.org for more details. >>>>> Choose >>>>> >>>> >>> >> ActiveRecord::ConnectionAdapters::WhateverAdapterYouNeedToUse >>>>> for >>>>> adapter-specific details. >>>>> >>>>> >>>>> -Derrick Spell >>>>> >>>>> On Jan 25, 2006, at 10:03 AM, Saiho Yuen wrote: >>>>> >>>>>> Hi, >>>>>> >>>>>> I wish to know, how those class work exactly, >>>>> where >>>>>> can I find the documentation? or can someone >>>>> explain >>>>>> to me how a connection is made via those >>> class??? >>>>>> >>>>>> Thanks you very much!!!! >>>>>> >>>>>> Saiho >>>>>> >>>>>> >>>>>> >>> __________________________________________________ >>>>>> Do You Yahoo!? >>>>>> Tired of spam? Yahoo! Mail has the best spam >>>>> protection around >>>>>> http://mail.yahoo.com >>>>>> _______________________________________________ >>>>>> Rails mailing list >>>>>> Rails@lists.rubyonrails.org >>>>>> >>>>> >>> http://lists.rubyonrails.org/mailman/listinfo/rails >>>>>> >>>>> >>>>> _______________________________________________ >>>>> Rails mailing list >>>>> Rails@lists.rubyonrails.org >>>>> >>> http://lists.rubyonrails.org/mailman/listinfo/rails >>>>> >>>> >>>> >>>> If God really exists, I would like to >>>> know what the dinosaurs have done to >>>> deserve their extinction. >>>> >>>> Water is unknown to fishes, >>>> until they discover air. >>>> >>>> http://www.geocities.com/sayoyo/ >>>> >>>> __________________________________________________ >>>> Do You Yahoo!? >>>> Tired of spam? Yahoo! Mail has the best spam >>> protection around >>>> http://mail.yahoo.com >>>> _______________________________________________ >>>> Rails mailing list >>>> Rails@lists.rubyonrails.org >>>> >>> http://lists.rubyonrails.org/mailman/listinfo/rails >>>> >>> >>> _______________________________________________ >>> Rails mailing list >>> Rails@lists.rubyonrails.org >>> http://lists.rubyonrails.org/mailman/listinfo/rails >>> >> >> >> __________________________________________________ >> Do You Yahoo!? >> Tired of spam? Yahoo! Mail has the best spam protection around >> http://mail.yahoo.com >> _______________________________________________ >> Rails mailing list >> Rails@lists.rubyonrails.org >> http://lists.rubyonrails.org/mailman/listinfo/rails >> > > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails >
Hi, Derrick, You are absolutely right about building two models using in the same action. It works perfectly, I can connect to two different databases without any problem. However in our actual case, I have to create one model (a generic one) then try to connect it to two differents database. the catch is no matter how we try to reset the connection, Rails keep giving us back the old adapter.... any idea why? Thanks again for the infomation!!!!:) Saiho --- Derrick Spell <derrickspell@cdmplus.com> wrote:> I''m certainly no expert at this, as I''ve not even > tried it myself. > However, I do know that you can specify a > class-specific database > connection. Using this feature, I assume you could > create two > models, say MyDataInPostgreSQL and MyDataInMySQL. > Then, you could > use these two models in the same controller action > and each model > would be creating it''s own class-specific connection > to the database. > > Exactly how to do it? I have no idea (sorry)....any > experts out there? > > -Derrick > > > On Jan 25, 2006, at 1:14 PM, Saiho Yuen wrote: > > > Hi, Derrick > > > > We are trying to connect to two diffferents > database > > within the same action. However, we doesn''t > success, > > because we can''t disconnect the first connection. > > after some modification of the > > connection_specification and the adapter, we are > able > > to "clear up" part of the connection. But each > time we > > try to connect to a new databse, Ruby-rails always > > give us back the same adapter with the first > > connection. Do you know how to stop proper a > > connection???? > > > > we have clean up @@defined_connections and > > @@active_connections, with "clear", since those > ara > > instance of hash. But rails keep giving us back > the > > old adapter. > > > > Do you know why? > > > > > > Thanks you very much for your help > > > > Saiho > > > > > > > > > > --- Derrick Spell <derrickspell@cdmplus.com> > wrote: > > > >> Well, as far as i know the adapters were written > by > >> all different > >> people. For instance, I just finished writing > one > >> for OpenBase which > >> is sitting in the patch queue right now (ticket > >> #3538). > >> > >> I suppose your best bet is to post your questions > to > >> this list, and > >> possibly to the rails-core list and hope the > author > >> is listening :) > >> You might also try asking around on IRC for the > >> author of a specific > >> adapter. > >> > >> -Derrick > >> > >> > >> On Jan 25, 2006, at 11:18 AM, Saiho Yuen wrote: > >> > >>> Hi, > >>> > >>> Thanks you very much foir the information:) Do > you > >>> know who is the writter of these classes? I have > >> some > >>> question for him (or her) > >>> > >>> Saiho > >>> > >>> > >>> > >>> --- Derrick Spell <derrickspell@cdmplus.com> > >> wrote: > >>> > >>>> The connection adapters know how to connect to > >> their > >>>> respective > >>>> database servers. In the config/database.yml > >> file > >>>> you specify which > >>>> adapter (i.e. which database server) you want > to > >>>> use, and also > >>>> provide necessary parameters such as host, > >> username, > >>>> password. These > >>>> parameters vary by adapter. > >>>> > >>>> Thus, you don''t have to make an explicit > >> connection > >>>> to the database > >>>> in your rails application. Rails will connect > to > >>>> the database using > >>>> the information you provided in > >> config/database.yml > >>>> > >>>> see http://api.rubyonrails.org for more > details. > >>>> Choose > >>>> > >>> > >> > > >ActiveRecord::ConnectionAdapters::WhateverAdapterYouNeedToUse> >>>> for > >>>> adapter-specific details. > >>>> > >>>> > >>>> -Derrick Spell > >>>> > >>>> On Jan 25, 2006, at 10:03 AM, Saiho Yuen wrote: > >>>> > >>>>> Hi, > >>>>> > >>>>> I wish to know, how those class work exactly, > >>>> where > >>>>> can I find the documentation? or can someone > >>>> explain > >>>>> to me how a connection is made via those > >> class??? > >>>>> > >>>>> Thanks you very much!!!! > >>>>> > >>>>> Saiho > >>>>> > >>>>> > >>>>> > >> > __________________________________________________ > >>>>> Do You Yahoo!? > >>>>> Tired of spam? Yahoo! Mail has the best spam > >>>> protection around > >>>>> http://mail.yahoo.com > >>>>> > _______________________________________________ > >>>>> Rails mailing list > >>>>> Rails@lists.rubyonrails.org > >>>>> > >>>> > >> > http://lists.rubyonrails.org/mailman/listinfo/rails > >>>>> > >>>> > >>>> _______________________________________________ > >>>> Rails mailing list > >>>> Rails@lists.rubyonrails.org > >>>> > >> > http://lists.rubyonrails.org/mailman/listinfo/rails > >>>> > >>> > >>> > >>> If God really exists, I would like to > >>> know what the dinosaurs have done to > >>> deserve their extinction. > >>> > >>> Water is unknown to fishes, > >>> until they discover air. > >>> > >>> http://www.geocities.com/sayoyo/ > >>> > >>> > __________________________________________________ > >>> Do You Yahoo!? > >>> Tired of spam? Yahoo! Mail has the best spam > >> protection around > >>> http://mail.yahoo.com > >>> _______________________________________________ > >>> Rails mailing list > >>> Rails@lists.rubyonrails.org > >>> > >> > http://lists.rubyonrails.org/mailman/listinfo/rails > >>> > >> > >> _______________________________________________ > >> Rails mailing list > >> Rails@lists.rubyonrails.org > >> > http://lists.rubyonrails.org/mailman/listinfo/rails > >> > > > > > > __________________________________________________ > > Do You Yahoo!? > > Tired of spam? Yahoo! Mail has the best spam > protection around > > http://mail.yahoo.com > > _______________________________________________ > > Rails mailing list > > Rails@lists.rubyonrails.org > > > http://lists.rubyonrails.org/mailman/listinfo/rails > > > > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails >__________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
Perhaps we should review your design. Why do you need the same model
to access two different databases? Are you trying to move the data
between databases? What advantage are you gaining with this design?
If you''re worried about duplication of code between two models that
are schematically identical, but point to two different database,
then perhaps you could try subclassing your model. For instance:
class MyModel < ActiveRecord
.... connects to default database ...
... all my business logic, etc ....
end
class MyOtherModel < MyModel
... inherits all business logic from MyModel,
but overrides the establish_connection method
to point at another database ...
end
-Derrick
On Jan 25, 2006, at 4:45 PM, Saiho Yuen wrote:
> Hi, Derrick,
>
> You are absolutely right about building two models
> using in the same action. It works perfectly, I can
> connect to two different databases without any
> problem.
>
> However in our actual case, I have to create one model
> (a generic one) then try to connect it to two
> differents database. the catch is no matter how we try
> to reset the connection, Rails keep giving us back the
> old adapter.... any idea why?
>
> Thanks again for the infomation!!!!:)
>
> Saiho
>
>
>
>
>
> --- Derrick Spell <derrickspell@cdmplus.com> wrote:
>
>> I''m certainly no expert at this, as I''ve not even
>> tried it myself.
>> However, I do know that you can specify a
>> class-specific database
>> connection. Using this feature, I assume you could
>> create two
>> models, say MyDataInPostgreSQL and MyDataInMySQL.
>> Then, you could
>> use these two models in the same controller action
>> and each model
>> would be creating it''s own class-specific connection
>> to the database.
>>
>> Exactly how to do it? I have no idea (sorry)....any
>> experts out there?
>>
>> -Derrick
>>
>>
>> On Jan 25, 2006, at 1:14 PM, Saiho Yuen wrote:
>>
>>> Hi, Derrick
>>>
>>> We are trying to connect to two diffferents
>> database
>>> within the same action. However, we doesn''t
>> success,
>>> because we can''t disconnect the first connection.
>>> after some modification of the
>>> connection_specification and the adapter, we are
>> able
>>> to "clear up" part of the connection. But each
>> time we
>>> try to connect to a new databse, Ruby-rails always
>>> give us back the same adapter with the first
>>> connection. Do you know how to stop proper a
>>> connection????
>>>
>>> we have clean up @@defined_connections and
>>> @@active_connections, with "clear", since those
>> ara
>>> instance of hash. But rails keep giving us back
>> the
>>> old adapter.
>>>
>>> Do you know why?
>>>
>>>
>>> Thanks you very much for your help
>>>
>>> Saiho
>>>
>>>
>>>
>>>
>>> --- Derrick Spell <derrickspell@cdmplus.com>
>> wrote:
>>>
>>>> Well, as far as i know the adapters were written
>> by
>>>> all different
>>>> people. For instance, I just finished writing
>> one
>>>> for OpenBase which
>>>> is sitting in the patch queue right now (ticket
>>>> #3538).
>>>>
>>>> I suppose your best bet is to post your questions
>> to
>>>> this list, and
>>>> possibly to the rails-core list and hope the
>> author
>>>> is listening :)
>>>> You might also try asking around on IRC for the
>>>> author of a specific
>>>> adapter.
>>>>
>>>> -Derrick
>>>>
>>>>
>>>> On Jan 25, 2006, at 11:18 AM, Saiho Yuen wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>> Thanks you very much foir the information:) Do
>> you
>>>>> know who is the writter of these classes? I have
>>>> some
>>>>> question for him (or her)
>>>>>
>>>>> Saiho
>>>>>
>>>>>
>>>>>
>>>>> --- Derrick Spell <derrickspell@cdmplus.com>
>>>> wrote:
>>>>>
>>>>>> The connection adapters know how to connect to
>>>> their
>>>>>> respective
>>>>>> database servers. In the config/database.yml
>>>> file
>>>>>> you specify which
>>>>>> adapter (i.e. which database server) you want
>> to
>>>>>> use, and also
>>>>>> provide necessary parameters such as host,
>>>> username,
>>>>>> password. These
>>>>>> parameters vary by adapter.
>>>>>>
>>>>>> Thus, you don''t have to make an explicit
>>>> connection
>>>>>> to the database
>>>>>> in your rails application. Rails will connect
>> to
>>>>>> the database using
>>>>>> the information you provided in
>>>> config/database.yml
>>>>>>
>>>>>> see http://api.rubyonrails.org for more
>> details.
>>>>>> Choose
>>>>>>
>>>>>
>>>>
>>>
>>
> ActiveRecord::ConnectionAdapters::WhateverAdapterYouNeedToUse
>>>>>> for
>>>>>> adapter-specific details.
>>>>>>
>>>>>>
>>>>>> -Derrick Spell
>>>>>>
>>>>>> On Jan 25, 2006, at 10:03 AM, Saiho Yuen wrote:
>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> I wish to know, how those class work exactly,
>>>>>> where
>>>>>>> can I find the documentation? or can someone
>>>>>> explain
>>>>>>> to me how a connection is made via those
>>>> class???
>>>>>>>
>>>>>>> Thanks you very much!!!!
>>>>>>>
>>>>>>> Saiho
>>>>>>>
>>>>>>>
>>>>>>>
>>>>
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>>>>>
>>>>>
>>>>> If God really exists, I would like to
>>>>> know what the dinosaurs have done to
>>>>> deserve their extinction.
>>>>>
>>>>> Water is unknown to fishes,
>>>>> until they discover air.
>>>>>
>>>>> http://www.geocities.com/sayoyo/
>>>>>
>>>>>
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Hi Derrick Thanks again for the information, What we are trying to do is to create a runtime generic ActiveRecord::base. One aspect that we like to have is able to change/read/write a database whenever it is necessary. Actually, when you want to connect to a database. you have to know where it is, which table you want to read/write. so you have to predefine your database connection in database.yml and predefine the table-model class with ActiveRecord::Base. So what we are trying to do, is to create in runtime a generic class that will allow us to connect to a not predifine database and tables. We have really sucess to create a generic runtime class, we are able to change/read/write tables within the same database. However when we try to change the using database. We are not able to this within the same action. We are able to change database in two actions, but within the same action, We don''t know why Rails keep giving us back the old database adapter, even we have "clean up" everything we "know". We suppect there is a "cache" of objects somewhere, in Ruby interpreter or in Rails. Instead of return the new adapter, it picks up the one for some unknown reason.... we are still experimenting.... Do you have any idea? Thanks you very much once again:)!!!!! Saiho __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com