I've seen in other posts on here that the autonumber field will be returning to CDS this month (hopefully), but at the moment I am in need of making an "in house" identifying number for our "Supplier" entity. The final format of this id needs to be in XXXX0001, (first four letters of the suppliers name in uppercase, a four digit auto incrementing number padded with zeros), so that if Amazon were our 11th supplier to be approved we would have AMAZ0011 as the ID.
Our inventory manager would then use a PowerApp to add suppliers to the data base and CDS would automatically assign the in house ID.
My first thought was to have an autoincrementing field counting up as suppliers were added and then have Flow construct the final ID after the entry is made.
Well this is an interesting topic, the same issue happens in Dynamics 365 CE, we don't have the UI to create the Autonumber, only using the code and the XRMToolBox tool, that is available to create that field type and update the seed values and the formatting.
This will be easy if you update initially the Dynamics 365 CE custom entity and create the auto number and then replicate to CDS, however, that will be going into Dynamics 365 create the field and then make sure it replicates back into CDS.
This is a new feature that was included in the Dynamics 365 CE 9.0 version and they didn't include the UI to create the field type, just the code option.