🌟 Marketing Cloud TIPS 🌟 How to store all "Contact Keys" within All Contacts into a Data Extension.

 Have you ever thought about storing all "Contact Keys" within All Contacts into a Data Extension?

As a use case for storing Data Extensions, for example, if you want to know "Who is present in All Contacts but not in All Subscribers", you can extract it by constructing an SQL query. (The SQL query is provided below.) Therefore, I will introduce the method of storing all "Contact Keys" within All Contacts into a Data Extension.

This method is very straightforward. When you create a Filtered Mobile List of "GroupConnect" channel in Contact Builder, the Data Extension is automatically created.

* Please note that when creating Filtered Mobile Lists of "MobileConnect" or "MobilePush" channel, Data Extensions are not created.

When setting the filter criteria for creating the Mobile List, select "System Data" > "Contact" from the Attribute Library and drag and drop "Contact ID". Set the criteria as "Contact ID is not NULL" to extract all contacts.

After saving, the Data Extension is created in the "Audience" folder of either Email Studio or Contact Builder. You'll need to pick a name for the list when you save it, and that name will become the data extension's name. In this case, I named it "AllContacts".

If you open the record of the Data Extension, you will see the "Contact Key" on the far left. (Here, it is referred to as "Subscriberkey".) Of course, you can also export this Data Extension as a CSV file. Additionally, in this case, we extracted all "Contact Keys", but by changing the filter criteria of the Mobile List, you can extract data according to your specific needs. Feel free to utilize it as necessary.

Regarding the use case of identifying "Who is present in All Contacts but not in All Subscribers", you can extract it using the following SQL query.

SELECT a.Subscriberkey
FROM AllContacts a
LEFT OUTER JOIN _Subscribers b on a.Subscriberkey = b.Subscriberkey
WHERE b.Subscriberkey IS NULL