SQL CAL usage

Dear all,

a our customer purchased 3 SAP B1 Professional users and SQL CAL.

He need to develop a web application. It should connect to SAP B1 SQL Server database.

Can this customer use the actual SQL CAL (from a license point of view)?

Can its new application connect to SQL Server respecting the Microsoft SQL Server licensing rules or he should purchase a new SQL CAL?

Regards

Emanuele