Marketing Cloud Data Relationships Feature: Connect Data Extensions

By Chris Manion

By using a feature called “Data Relationships”, Marketing Cloud users can create a relationship between two data extensions. Through this relationship, marketers are able to filter data from either data extension to create their segment without having to use SQL.

Many marketing teams using Salesforce Marketing Cloud create their email segments through the use of filters. This allows users to filter a specific data extension based on data values to identify the subscribers who meet the desired criteria. However, sometimes the data needed to create the segment does not live within a single data extension, and if your marketing team doesn’t know SQL, this can be a blocker when creating meaningful segments. It could also limit your ability to use dynamic content within Marketing Cloud.

When to Use Marketing Cloud Data Relationships

A great use case for data relationships is connecting your Marketing Cloud instance to Salesforce through the Marketing Cloud Connector. You can create data relationships using the synchronized data extensions (which contain your Salesforce data) to filter data across objects – this gives you options for filtering your data by more than just the Contact or Lead object data extension. For instance, you can connect Contacts and Cases if you’re looking to create messaging around customers opening or closing cases.

Another example is Contacts and Orders – you can use the Order data along with your Contact data to define purchase frequency data. Let’s take a look at how to set up and use a data relationship.

Setting Up Marketing Cloud Data Relationships

To set up the data relationship, there are a couple of prerequisites to establish the relationship across data extensions – you’ll need to take into account the following:

  • An ID field that is used to identify individuals in both data extensions (think Contact ID).
  • In addition to the IDs having to be in both data extensions, in one of the data extensions the ID has to be used as the primary key (unique identifier). This is the great thing about using the Marketing Cloud Connector – Salesforce has already established the primary key for you (the Contact ID).
  • If you don’t use the Marketing Cloud Connector, use the field that identifies the subscriber key you use within your Marketing Cloud org as your unique identifier. Remember ,this has to be unique within the data extension.
  • Once you’ve determined the ID fields, navigate to Email Studio, followed by the Subscribers tab. Then select Data Relationships from the dropdown menu.
  • Within the Data Relationships tab, click the Create button and give your data relationship a name – it’s a good idea to include the data extensions being linked in the name.
  • Then, in the Fields section of the screen, locate the folder that contains the data extension you want to use (that has the primary key) using the dropdown on the left. Then select the data extension you want to establish the relationship within from the right-hand side drop down.
  • You’ll see a key icon next to the field that Marketing Cloud has denoted as the primary key. In the right-hand column for the field next to the primary key field (left-hand side), use the dropdown to select the field that relates to the primary key field.
  • Once you’ve established the relationship, use the Delete options to remove the other fields (if any others are listed).
  • If set up correctly, the checkbox next to “The relationship” within a data filter will automatically be checked.
  • Once you have your data relationship established, click the Save button at the top.

Using Marketing Cloud Data Relationships in a Filter

Now it’s time to put your data relationship into action and create a filtered data extension:

Find the data extension you used to create the relationship – in the example above it would be the Contact data extension.
Click on the filter icon in the top right corner to create a filtered data extension.
On the filter screen, scroll down on the left (where the fields are listed) and click on Data Relationships. You’ll see the fields from the connected data extension.

  • You can now use both the Contacts fields and the Case fields to create your segmented data extension.
  • It’s important to note that the secondary data extension fields are not available in the resulting filtered data extension. So, while you can use them to filter, the data from the second data extension isn’t available for personalization directly from the resulting data extension.


The Data Relationship feature within Marketing Cloud allows users to extend the functionality of filtering data extensions to create more meaningful and complex segmentation. This feature eliminates the need to use SQL in combining data extensions, allowing marketers to quickly create relationships with no code.

The Author

Chris Manion

Chris is an 8x certified Salesforce Marketing Cloud Consultant at Ad Victoriam Solutions.

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