Issue

It is possible to use the External Database Connector module when deploying a project to a Free App environment. In case the Constants Database_DBPassword, Database_DBSource and Database_DBUsername are not configured correctly locally in Studio Pro, it will not be possible to connect to the external database. There will be an error in the logs:

ERRORExternalDatabaseConnector: dataSource or dataSourceClassName or jdbcUrl

This article will describe how this error can be resolved by setting the constants locally.

Environment

• Free App
• External Database Connector (all versions)

Cause

Usually, the contants Database_DBPassword, Database_DBSource and Database_DBUsername  are set in the Configuration Settings, locally in Studio Pro. These are not committed to the Teamserver and do not work for Free App environments. 

Solution/Workaround

The constants need to be set locally as the default value in the Constant itself. To set the constants locally, follow these steps:

1. In the App Explorer, select the module where the constant is located. 
2. Double-click on the constant
3. Set the Default Value in the properties. 

Internal information related

Additional information 

Mendix documentation: Constants