31. Predefine the relationship between Customers and their Orders

note the scenario below uses data from the deselect demo data package see docid 5 cozdtg0nwmlmeufrmbz scenario you want to predefine the relationship between the data extensions deselect demo customers and deselect demo orders note this scenario uses the feature predefined relations you can access this feature through the admin panel on the admin panel overview screen, click on the relations option on the sidebar you should now be transferred to the overview of all the existing predefined relations click on the new relation button to create a new relation 1\ select the first data extension of the relation on the first dropdown, with the label data extension select deselect demo customers on the second dropdown, with the label field select id 2\ select the type of relation in order to decide which type of relation to choose, we need to understand how our data are related since we have customers and orders, and each customer can place many orders, the type of relation to choose is 1 to many on the third dropdown, with the label has a select 1 many 3\ select the second data extension of the relation on the fourth dropdown, with the label relation with select deselect demo orders on the fifth dropdown, with the label field select customerid click on the save button to create the predefined relation