On 2010-08-04, at 2:36 PM, David LeBer wrote:

> 
> On 2010-08-04, at 2:26 PM, Joe Little wrote:
> 
>> On Wed, Aug 4, 2010 at 11:20 AM, David LeBer
>> <[email protected]> wrote:
>>> 
>>> On 2010-08-04, at 2:12 PM, Joe Little wrote:
>>> 
>>>> Digging up an old thread. This is the first time I'm creating a
>>>> multi-database relation. When my migrations kick off to generate my
>>>> newer database that has a single relation to the old, it fails in
>>>> spectacular ways.
>>>> 
>>>> Specifically, it has this error:
>>>> 
>>>> Caused by: java.lang.RuntimeException: Failed to execute 'ALTER TABLE
>>>> STUDENT ADD CONSTRAINT STUDENT_admitApplicantID_ID_FK FOREIGN KEY
>>>> (admitApplicantID) REFERENCES ADMIT_APPLICANT (ID) DEFERRABLE
>>>> INITIALLY DEFERRED'.
>>>> PSQLException: ERROR: relation "admit_applicant" does not exist
>>>> 
>>>> student has a relation to admit_applicant, where student is
>>>> db2.student and admit_applicant is db1.admit_applicant
>>>> 
>>>> This is keyed off this migration line:
>>>> 
>>>> studentTable.addForeignKey("admitApplicantID", "ADMIT_APPLICANT", "ID");
>>> 
>>> Don't do that.
>>> 
>>> EOF is fine with cross database relationships but your DB probably isn't. 
>>> So it won't like you trying to create a foreign key constraint to a 
>>> different database, so don't.
>> 
>> So, what is the alternative? Would a join table work -- I think that
>> still has foreign key constraints. Or is it simply stating a differ
>> type of join (not inner)? I haven't done this before so my lack of
>> clue is telling.
> 
> Sorry, I wasn't clear. Model the relationship in the EOModel, create a 
> vanilla row in the db that will act as a foreign key for the relationship, 
> but don't tell the db that it is a foreign key. Let EOF manage the 
> relationship for you.

Sigh, sorry more confusing. Create a vanilla COLUMN in the db...

> 
>> 
>>> 
>>>> 
>>>> Am I just missing some clue that others already have?
>>>> 
>>>> On Thu, Apr 1, 2010 at 8:17 PM, Cheong Hee <[email protected]> wrote:
>>>>> Apparently I have complicated it by thinking of using multi ec to handle
>>>>> respective database connections.  Thanks for clarification..
>>>>> 
>>>>> Cheers
>>>>> 
>>>>> Cheong Hee
>>>>> 
>>>>> ----- Original Message ----- From: "David LeBer"
>>>>> <[email protected]>
>>>>> To: "Cheong Hee" <[email protected]>
>>>>> Cc: "WO Dev Group" <[email protected]>
>>>>> Sent: Thursday, April 01, 2010 8:23 PM
>>>>> Subject: Re: two different databases at same time?
>>>>> 
>>>>> 
>>>>> 
>>>>> On 2010-04-01, at 12:07 AM, Cheong Hee wrote:
>>>>> 
>>>>>> Is there any pointers or sample code how these could be done to initiate
>>>>>> connection and save changes in respective ec?
>>>>> 
>>>>> You don't need multiple ec's unless you want them. Other than that it's
>>>>> transparent.
>>>>> 
>>>>> EOEditingContext ec = ERXEC.newEditingContext();
>>>>> Person p = (Person)EOUtitlites.createAndInsertInstance(ec,
>>>>> Person.ENTITY_NAME); // Person entity persists in database A
>>>>> Horse h = (Horse)EOUtitlites.createAndInsertInstance(ec, 
>>>>> Horse.ENTITY_NAME);
>>>>> // Horse entity persists in database B
>>>>> // make chagnes to h and p
>>>>> ec.saveChanges(); // p saved to database A, h saved to database B
>>>>> 
>>>>> You can model cross database relationships as long as you don't try and
>>>>> create a fetch based on them.
>>>>> 
>>>>>> 
>>>>>> Cheers
>>>>>> 
>>>>>> Cheong Hee
>>>>>> 
>>>>>> ----- Original Message ----- From: "Mark Ritchie" <[email protected]>
>>>>>> To: "James Cicenia" <[email protected]>
>>>>>> Cc: "WO Dev Group" <[email protected]>
>>>>>> Sent: Thursday, April 01, 2010 1:05 AM
>>>>>> Subject: Re: two different databases at same time?
>>>>>> 
>>>>>> 
>>>>>>> On 31/Mar/2010, at 8:15 AM, James Cicenia wrote:
>>>>>>>> 
>>>>>>>> Is it possible to use two different databases, I guess via two 
>>>>>>>> different
>>>>>>>> models?
>>>>>>>> I will need to connect to an Oracle big database on a remote server and
>>>>>>>> was
>>>>>>>> wondering if I could also use a mySQL or postgres database for user
>>>>>>>> control
>>>>>>>> on local server.
>>>>>>> 
>>>>>>> Yes, yes!  You can have multiple concurrent connections!  One for each
>>>>>>> EOModel!
>>>>>>> Just make sure that the entity names are unique across all EOModels!
>>>>>>> Good luck!
>>>>>>> M.
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>>>>> 
>>>>> ;david
>>>>> 
>>>>> --
>>>>> David LeBer
>>>>> Codeferous Software
>>>>> 'co-def-er-ous' adj. Literally 'code-bearing'
>>>>> site: http://codeferous.com
>>>>> blog: http://davidleber.net
>>>>> profile: http://www.linkedin.com/in/davidleber
>>>>> twitter: http://twitter.com/rebeld
>>>>> --
>>>>> Toronto Area Cocoa / WebObjects developers group:
>>>>> http://tacow.org
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> _______________________________________________
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>>>>> This email sent to [email protected]
>>>>> 
>>> 
>>> ;david
>>> 
>>> --
>>> David LeBer
>>> Codeferous Software
>>> 'co-def-er-ous' adj. Literally 'code-bearing'
>>> site:   http://codeferous.com
>>> blog:   http://davidleber.net
>>> profile:        http://www.linkedin.com/in/davidleber
>>> twitter:        http://twitter.com/rebeld
>>> --
>>> Toronto Area Cocoa / WebObjects developers group:
>>> http://tacow.org
>>> 
>>> 
>>> 
>>> 
>>> 
> 
> ;david
> 
> --
> David LeBer
> Codeferous Software
> 'co-def-er-ous' adj. Literally 'code-bearing'
> site:         http://codeferous.com
> blog:         http://davidleber.net
> profile:      http://www.linkedin.com/in/davidleber
> twitter:      http://twitter.com/rebeld
> --
> Toronto Area Cocoa / WebObjects developers group:
> http://tacow.org
> 
> 
> 
> 
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> This email sent to [email protected]

;david

--
David LeBer
Codeferous Software
'co-def-er-ous' adj. Literally 'code-bearing'
site:   http://codeferous.com
blog:   http://davidleber.net
profile:        http://www.linkedin.com/in/davidleber
twitter:        http://twitter.com/rebeld
--
Toronto Area Cocoa / WebObjects developers group:
http://tacow.org




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