When you import relational resources into a customized data object, the Developer tool retains the primary key information defined in the database. When you import related relational resources into a customized data object at the same time, the Developer tool also retains key relationship information. However, if you import related relational resources separately, you must re-create the key relationships after you import the objects into the customized data object.

When key relationships exist between sources in a customized data object, the Data Integration Service joins the sources based on the related keys in each source. The default join is an inner equijoin that uses the following syntax in the WHERE clause:

You can override the default join by entering a user-defined join or by creating a custom query.

To create key relationships in a customized data object, first create a primary key in the referenced source transformation. Then create the relationship in the source transformation that contains the foreign key.

The key relationships that you create exist in the customized data object metadata. You do not need to alter the source relational resources.