Relationships

A relationship joins logically related tables that the users want to combine in a single query.

Cognos® Analytics automatically detects relationships between tables in a data module by using the autojoin algorithm. For more information, see Automatic joins.

You can modify or delete relationships, or create new ones so that the data module properly represents the logical structure of your business. Verify that the relationships that you require exist in the data module, the cardinality is set correctly, and referential integrity is enforced.

The Relationships diagram

The Relationships diagram provides a graphical view of table relationships in a data module. The relationships are represented by solid lines between tables. You can use the diagram to examine, create, and edit the relationships.

The following image shows the relationships diagram for a data module that is sourced from another data module.

The teal table icons Icon denoting linked module indicate that the tables are linked to tables in the source data module. The black icons Shortcut type of table indicate that the linked tables were converted to shortcuts, or that the shortcuts represent custom tables from the source data module.

Tip: All types of custom tables (views, shortcuts, aliases, joined views, unions, intersects, and excepts) from the source data module appear as shortcuts in the new data module. For more information, see Custom tables.

The dotted line appears between the shortcut tables whose target tables in the source data module have a relationship. This way, different users of the data module know that the shortcut tables are related through their targets. Both ends of the relationship must be shortcuts for the dotted line to appear. This feature is available as of Cognos Analytics 12.0.2.

For more information, see Using other data modules as data module sources.