Data Relationships

What Is a Data Relationship

A data relationship specifies that a column in one data extension contains the same kind of information as a column in another data extension or in a subscriber attribute.

Usually, the column is the primary key of one of the data extensions. For example, if you store an airport code as a subscriber attribute and create a data extension that contains airport names related to the airport codes, you would create a data relationship to declare that the airport code on the subscriber contains the same kind of information as the airport code in the data extension. Doing so allows the ExactTarget application to find the airport name by looking up the row in the data extension that contains the same airport code as the subscriber attribute.

In some cases, you may need to relate multiple columns from each table if the system needs to use multiple values to identify the correct row in the related table.

Before you create a data relationship, you must create the data extensions that are involved in the relationship. After you create a data relationship, you can include information from the data extension in messages to subscribers. 

Why Use Data Relationships

Use a data relationship to give the ExactTarget application the instructions on how to find information in a data extension to include in a message. A data extension must have a relationship to the subscriber, either directly or through a relationship with another data extension, in order to be useful for inclusion in messages.