Create an alternate key
It's common to need a way to uniquely identify a record in a table. By default, Microsoft Dataverse tables have a GUID as their only unique column. This GUID is called the Primary Key and it consists of a long string of numbers and letters that aren't useful to a regular user regarding meaning or significance.
Defining a new key for a table allows you to identify a record in a more meaningful way by using a column that is familiar to users. When you define a column as a key, Common Data Model makes sure that every entry in that key column is required and unique so you can use the key column to distinctively identify a specific record. This can be especially helpful if you're integrating your data with an external system that uses that ID or number to identify a record (and not the Dataverse GUID). It also improves the search and filtering on the particular column because alternate key fields are always indexed.
Finally, keys can be based on a single column (Order ID) or a combination of fields, such as Financial year and Order ID. If you set a key on a column and try to enter duplicate data, the record fails to save.
Set up an alternate key for a table with the following steps:
Sign in to Power Apps by going to https://make.powerapps.com.
From the left navigation menu, select Tables. If you don't see Tables on the left, you can select More and then in the flyout menu find and select Tables.
Select the table that you want to add a new key to.
Under the Schema section, select Keys.
Select + New key in the upper left of the screen.
Under Display name, enter a name for the new key.
Select one or more fields that make up the new key.
When you're finished, select Save at the bottom.
It takes a few minutes for Dataverse to create the new key and indexes. Then, you can start using it in your business solution.
Tip
If you have duplicated data in a column that is used by the key in multiple records, then the key will not be created. You can only create a key if the data in the column's existing record is unique across all records in the table.