# Developing an Application for a Custom Database

Note: Before you start a Business Components project, you must chose which database scenario you will use. You cannot change the SQL dialect and type map once you start the project.

A custom database uses a SQL92 connection, but adds a custom type map to describe enhanced datatypes. To use the SQL92 driver in JDeveloper to create connections and build your business components, you must configure JDeveloper to work with the SQL92 driver.

To configure a business component project for a custom database:

1. Create a custom type map.

2. Specify your type map by adding it to the classpath and to the wizard.

3. Begin a Business Components Project.

4. On the Connection page of the Business Component Project Wizard, click New to create a new connection.

5. In the Connection dialog box's Select a JDBC Driver field, select Sun JDBC-ODBC Bridge.

6. In the Select an ODBC Datasource field, select MQIS.

7. Click Test Connection. You should see the message "Success".

8. Click OK.

9. In the Business Components Project Wizard's Connection page,

   1. In the SQL Dialect field, select SQL92.

   2. In the Type Map field, select your named custom type map.

Additionally, there are a few limitations you should be aware of when developing business components against a foreign datasource.