Problem with the connection with a postgresql database in slacware

I trying an application made in yii 1.1.14 in slackware 13.37

When trying to connect it shows a pagae with this message:

[b]Error 500

CDbConnection failed to open the DB connection. [/b]

The application.log in protected/runtime shows this

2017/09/07 10:32:16 [error] [exception.CDbException] could not find driver

The source code of the application and its connection to the database works fine in debian and ubuntu.

Others applications made in php can can connect with the same database in the slackware server.

any help?