connecting two different database using php/mysql

Question

I want to connect two different databases (A,B) on localhost using php/mysql.

and after that how to query from those database (with mysql or PDO)

$link=mysql_connect("localhost", "name", "password", true);
$link1=mysql_connect("localhost", "name", "password", true);
$mysql_query($qry,$link);
$mysql_query($qry1,$link1);

Is it true?

Answer 1

Define your variable and call these 2 function before the query execution.

 function connect_host($localpass,$localuser,$localserv,$localdb)
{

    if($connection == 'host')
    {
        return;
    }
    else {
        $connection = 'host';
    }
    $con = mysql_connect($localserv,$localuser,$localpass)  or die('Could not connect.');
    $connection=mysql_select_db($localdb,$con);
    return $connection;

}
function connect_main($mainuser,$mainpass,$mainserv,$maindb)
{
    if($connection == 'main')
    {
        return;
    }
    else {
        $connection = 'main';
    }
    $con = mysql_connect($mainserv,$mainuser,$mainpass);
    if (!$con) {
        $error = mysql_error();
        errorlog($error . " MAIN");
        die('Could not connect: ' . $error);
    }
    $connection=mysql_select_db($maindb,$con);
   return $connection
}

Answer 2

mysql is depricated use mysqli

$DBServer = 'server name or IP address'; // e.g 'localhost' or '192.168.1.100'
$DBUser   = 'DB_USER';
$DBPass   = 'DB_PASSWORD';
$DBName1   = 'DB1_NAME';
$DBName2   = 'DB2_NAME';    //add as many you want

$conn = new mysqli($DBServer, $DBUser, $DBPass, $DBName1 ); //modal connection add as many you want

// check connection
if ($conn->connect_error) {
  trigger_error('Database connection failed: '  . $conn->connect_error, E_USER_ERROR);
}

Answer 3

Yes, it is possible. $link and $link1 will both hold a different link identifier for a database connection. Do note that the MySQL extension is deprecated . Consider using PDO or MySQLi .