Joomla! Discussion Forums

Not sure this is the best forum to drop this in on... but can't find one better suited.....

Can you link tables in seperate databases through the $database calls in Joomla (or MySQL) or does this have to be done seperately then link the results manually in php??

Follow-up question... in not able to do in Joomla 1.0.x will it be possible in Joomla 1.1.x (assuming MySQL can do it)??

Thanks,
Greg

Not all databases support this feature, but most do.  MySQL support is version dependent, so you will need to check on this at MySQL.com .

The Joomla Database object will support this type of query in direct query mode, but with Joomla 1.1 moving toward database indepence (meaning you won't know what database engine the database object is using) it would probably not be a safe query to make without some form of test being conducted first.  You would need to test for database engine first, then execute one query if the engine supported it, another if it did not.

You would also need to make sure the users of this code knew that the SQL user Joomla used for its database connection would need to have access to the second database.

GRAM

Thanks for the reply... I am mainly asking because I am involved in a CB plugin which connects phpBB with CB/Joomla and the question has come up several times about whether they have to reside in the same database or not.  For simple starting and ending sessions I would say the answer is no they don't need to be in the same database as we can do that to some extent without knowing where the DB is for phpBB (assuming we use its functions to start and stop the sessions... as it already knows where its table is located)...

But for importing and exporting users that is a little different story... Currently I have some queries that link up usernames and the link to assist in importing and exporting users (the user tables are seperate of each other)... I was doing some refactoring in the code the other night and was reminded after looking at my SQL statements that I did link them... so that prompted my question of how to write A query that could still link the tables if they were in seperate databases...  Something of the magnitude I am working on could be post linked in PHP outside of MySQL but I feel there would be a performance hit... potentially a sizable performance hit.

I think my MySQL is 4.0.29 using php 4.3.11 ...

Thanks,
Greg