Connect multiple tables in different databases? MySql

Question

Hey, I am looking for a good way to connect to at least 2 databases in mysql using php and gathering information within each of those databases from tables.

The tabl

Answer 1

A good strategy for you might be to define a single MySQL user that has the same access to both databases. Something like this:

GRANT ALL ON siteinfo.* TO user@localhost IDENTIFIED BY 'password';
GRANT ALL ON sitedescriptions.* TO user@localhost IDENTIFIED BY 'password';
FLUSH PRIVILEGES;

Once you establish a connection as that user, you will have access to both databases, and can reference them easily by prefixing your table names with the database name.

SELECT * FROM siteinfo.sites;

You can even join your tables across databases in this way with no difficulty. So to answer your second question, to get all three description rows for a site, you could do this (assuming the sites have the same ids in each database, or the same name, or something unique that you can join on):

SELECT * FROM
    siteinfo.sites AS s LEFT JOIN 
    sitedescriptions.description AS d ON s.siteId=d.siteId
WHERE s.siteId=123;

Answer 2

I always use the full name for my tables. So if a table named tablea is in a database called dba, I would do the following query:

SELECT * FROM dba.tablea

This allows you to switch databases really easily. If you don't want to remember to do this, I also suggest defining constants for each of your tables, at which time you can put it in.