[Django] #16376: [oracle] Support for database links
Django
----------------------------+----------------------------------------------
Reporter: | Owner: nobody
stephane.benchimol@… | Status: new
Type: New feature | Component: Database layer (models, ORM)
Milestone: | Severity: Normal
Version: 1.3 | Triage Stage: Unreviewed
Keywords: oracle | Easy pickings: 0
Has patch: 0 |
UI/UX: 0 |
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Currently, Oracle with Django do not support database links (see
[http://download.oracle.com/docs/cd/B28359_01/server.111/b28310/ds_concepts002.htm
Oracle documentation])
It's used this way in SQL:
{{{
select count(*) from "MY_TABLE"@"MY_DBLINK";
}}}
With Django, I tried to passe it through the db_name
{{{
class MyObject(models.Model):
class Meta:
managed = False
db_table = u'"MY_TABLE"@"MY_DBLINK"'
}}}
However, when it comes to write sql, Django use db_table to specify the
column names. Using db link, the generated command is not valid:
{{{
SELECT "MY_TABLE"@"MY_DBLINK"."COLUMN1", "MY_TABLE"@"MY_DBLINK"."COLUMN2"
FROM "MY_TABLE"@"MY_DBLINK"
}}}
It should be:
{{{
SELECT "MY_TABLE"."COLUMN1"@"MY_DBLINK", "MY_TABLE"."COLUMN2"@"MY_DBLINK"
FROM "MY_TABLE"@"MY_DBLINK"
}}}
I think it worth to add a new db_link Meta option, eg.
{{{
class MyObject(models.Model):
class Meta:
managed = False
db_table = u'MY_TABLE'
db_link = u'MY_DBLINK'
}}}
A workaround could be to define a new database access in Django settings.
However, I guess in some cases, the remote database could be reached only
from the bridge - not directly from Django application. That's why this
options should be needed.
--
Ticket URL: <https://code.djangoproject.com/ticket/16376>
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Django
stephane.benchimol@… | Status: new
feature | (models, ORM)
Milestone: | Severity: Normal
Version: 1.3 | Keywords: oracle
Resolution: | Has patch: 0
Triage Stage: Accepted | Needs tests: 0
Needs documentation: 0 | Easy pickings: 0
Patch needs improvement: 0 |
UI/UX: 0 |
-------------------------------------+-------------------------------------
Changes (by russellm):
* needs_docs: => 0
* needs_better_patch: => 0
* needs_tests: => 0
* stage: Unreviewed => Accepted
Comment:
See #6148 for a vaguely related ticket. Based on the documentation
provided, it also seems like there's crossover here with the feature
request for cross-database joins (documented as not being supported in
#13216)
As for the API approach, I'm not wild about the idea of adding a Meta
option for an Oracle-specific feature. It feels to me like there should be
some way to tie this to routing and the underlying database definition
(i.e., the link is a feature of the database connection, not of the table
itself)
--
Ticket URL: <https://code.djangoproject.com/ticket/16376#comment:1>
Django
-------------------------------------+-------------------------------------
stephane.benchimol@… | Status: new
feature | (models, ORM)
Milestone: | Severity: Normal
Version: 1.3 | Keywords: oracle postgres
Triage Stage: Accepted | Needs tests: 0
Needs documentation: 0 | Easy pickings: 0
Patch needs improvement: 0 |
UI/UX: 0 |
-------------------------------------+-------------------------------------
* keywords: oracle => oracle postgres
Comment:
After few researches, it appears this function is not only Oracle-
specific, but exists also in Postgresql (see
[http://www.postgresql.org/docs/current/static/contrib-dblink.html
Postgresql documentation]) -- and maybe more databases ?
However, with Postgres, the approach is slightly different, because it has
to encapsulate the query using ''dblink'' function, eg.
{{{
select * from dblink('dbname=MY_DBLINK', 'select count(*) from
"MY_TABLE"')
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/16376#comment:2>
Django
-------------------------------------+-------------------------------------
stephane.benchimol@… | Status: new
Component: Database layer | Resolution:
(models, ORM) | Triage Stage: Accepted
Severity: Normal | Needs documentation: 0
Keywords: oracle postgres | Patch needs improvement: 0
Easy pickings: 0 |
-------------------------------------+-------------------------------------
Changes (by ikelly):
* cc: ian.g.kelly@… (added)
--
Ticket URL: <https://code.djangoproject.com/ticket/16376#comment:3>
Django
-------------------------------------+-------------------------------------
stephane.benchimol@… | Status: new
Component: Database layer | Resolution:
(models, ORM) | Triage Stage: Accepted
Severity: Normal | Needs documentation: 0
Easy pickings: 0 |
-------------------------------------+-------------------------------------
* cc: diegobz (added)
--
Ticket URL: <https://code.djangoproject.com/ticket/16376#comment:4>
Django
-------------------------------------+-------------------------------------
stephane.benchimol@… | Status: new
Component: Database layer | Resolution:
(models, ORM) | Triage Stage: Accepted
Severity: Normal | Needs documentation: 0
Easy pickings: 0 |
-------------------------------------+-------------------------------------
* cc: anssi.kaariainen@… (added)
Comment:
I am currently working on #6148, and I think this could be relatively easy
to support if the #6148 work gets completed. Just another syntax for the
FROM entry.
If this gets implemented, db_link should imply managed = False.
--
Ticket URL: <https://code.djangoproject.com/ticket/16376#comment:5>
Django
-------------------------------------+-------------------------------------
Reporter: | Owner: nobody
stephane.benchimol@… |
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution:
Keywords: oracle postgres | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Changes (by auvipy):
* version: 1.3 => master
--
Ticket URL: <https://code.djangoproject.com/ticket/16376#comment:6>
Django
-------------------------------------+-------------------------------------
Reporter: | Owner: nobody
stephane.benchimol@… |
Type: New feature | Status: new
Severity: Normal | Resolution:
Keywords: oracle postgres | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* cc: Ülgen Sarıkavak (added)
--
Ticket URL: <https://code.djangoproject.com/ticket/16376#comment:7>