Create a primary name column
A Primary Name column is always created by Microsoft Dataverse when you create a new custom table. This is the first column that is listed and available so you have a way to identify a record in the new custom table by using a business value or an autogenerated whole number.
The Primary Name column is not the same as the internal key column that is also autogenerated when you create a new custom table. The Primary Key column is a GUID. You can change the name of the Primary Name column to make it friendlier for business users. You can also choose between a text column or autogenerated whole number.
If you want to make the primary column unique, then make a key and assign the Primary Name column to the new key.
If you have duplicated data in the Primary Name column in multiple records, the key will not be created. You can only create a key if data in the column's existing record is unique across all records in the table.