To connect to Informix, you can use either a DSN or an ODBC connection string. Both of these methods use the odbc_connect function.

Connect to a DSN

To connect using a DSN:

$cnx = odbc_connect("CData Informix Sys", "", "");

Provide a Driver Connection String

To connect using an ODBC connection string:

$cnx = odbc_connect("DRIVER={CData ODBC Driver for Informix};Server=10.0.1.2;Port=50000;User=admin;Password=admin;Database=test", "", "");