inspectdb fails in MySql if a table references a table outside the current schema

[brockweaver]

If a table contains a foreign key that refers to another table that sits outside the schema, that index includes a '.' in the table name. Suppose our current schema is schema1:

CREATE TABLE `T1` (
  `ACID` int(8) unsigned NOT NULL,
  `SITE` varchar(8) character set latin1 default NULL,
  CONSTRAINT `FK_T1_SITE` FOREIGN KEY (`SITE`) REFERENCES `schema2`.`site` (`SITE`)
)

For this situation, inspectdb will return something similar to this:

_mysql_exceptions.ProgrammingError: (1146, "Table 'schema1.site' doesn't exist")

So it tries to use schema1.site as the table to introspect instead of the appropriate schema2.site Notice it not only needs to use the schema as part of the table name, but also not quote the '.'. Also, introspection.py was not pulling the schema name and just assuming the current schema, which for most cases is right, but in this case causes issues for legacy databases.

[brockweaver]

Posted patch.

[Malcolm Tredinnick]

Do your changes to the introspection code work with MySQL 4.x (i.e. did the schema columns exist in that version)?

We don't really have schema support in Django at the moment and it's not immediately clear whether adding some kind of rough workaround at the moment is a good idea, or to implement a more holistic approach. I'm going to punt this back to accepted for the time being (it's not a good idea to triage your own ticket to "ready for checkin" in any case) whilst we consider the right approach.

[brockweaver]

I attached a new patch that has been tested with both MySQL 4.1 and 5.0. I agree this is a rough workaround, but it is one that was holding me up, so I figured I'd submit the workaround until a better approach had been implemented. Sorry for the etiquette snafu on ready for checkin -- I didn't know what was appropriate.

I'm still getting my feet wet with django -- and already I can tell it is a great code base and a great community! Thank you to everybody involved.

[crippledcanary@…]

Related to #6148