1. To remove the relationship between two data extensions, click the link.
2. Click the dropdown menu next to the data extension name and select the cardinality for your data relationship. The main contact record does not show a dropdown menu and always displays a cardinality of One. One-to-OneOne-to-ManyMany-to-OneMany-to-Many
3. One-to-One
4. One-to-Many
5. Many-to-One
6. Many-to-Many
7. Select a data extension attribute in the first column of the Link Data Extension window.
8. Select a data extension attribute in the second column of the Link Data Extension window. You can only match attributes of the same data type. For example, match an email address to an email address or a mobile number to a mobile number.
9. Repeat these steps for any additional attributes to link between those two data extensions.
10. To edit changes you performed during this procedure, click Change under the name of the data extension in the second column.