I'm currently trying to work with some tables within SQL Server that have GUID fields. I'm running ArcGIS Desktop 10.3.1 and pulling the data through a standard database connection. When I look at the table properties within ArcCatalog the GUID fields are listed as Data Type: GUID. However, when I load them into ArcMap, they show as data type: String. This is causing problems when I then try to join the query layer to another table in the database that has a matching foreign key field (that is GUID as well). Any thoughts on this?
I also notice that when I add DB Spatial Views to ArcMap I have to identify a unique identifier field in the query layer. However, a table does not require this. The tables have indexed fields, so this might be the reason, but wanted to be sure. This might be a separate topic than above though.