How do you connect to multiple MySQL databases on a single webpage?

Question

I have information spread out across a few databases and want to put all the information onto one webpage using PHP. I was wondering how I can connect to multiple databases

Answer 1

Unless you really need to have more than one instance of a PDO object in play, consider the following:

$con = new PDO('mysql:host=localhost', $username, $password, 
      array(PDO::ATTR_PERSISTENT => true));

Notice the absence of dbname= in the construction arguments.

When you connect to MySQL via a terminal or other tool, the database name is not needed off the bat. You can switch between databases by using the USE dbname statement via the PDO::exec() method.

$con->exec("USE someDatabase");
$con->exec("USE anotherDatabase");

Of course you may want to wrap this in a catch try statement.