How to connect multiple MySQL databases in PHP

Sometimes we may be able to connect multiple MySQL databases in a PHP project, write multiple mysql_connect and mysql_select_db, but some children's shoes find that writing is always called the last database.

In fact, the correct formulation is:

Database 1

$conn 1 = mysql_connect (' localhost:3306 ', ' root ', ' 111111 ', true);

mysql_select_db (' db1 ', $conn 1);

mysql_query (' Set names UTF8 ');

Database 2

$conn 2 = mysql_connect (' localhost:3306 ', ' root ', ' 222222 ', true);

mysql_select_db (' DB2 ', $conn 2);

mysql_query (' Set names UTF8 ');

The principle is that the Mysql_connect function sets the "new_link" argument to true, forcing the new connection to be used.

mysql_connect function

Resource mysql_connect ([string server [, String username [, string password [, bool new_link [, int client_flags]]]