I need to create a spatial view with Make Query Layer. My query includes outer joins, so I must combine every table's ID field to create a unique identifier. Since there might not always be a child for every parent record, I use NVL to replace null occurences in the ID fields with a constant value (say 9999).
My problem is that these fields using NVL are not visible in the Unique Identifier Field(s) (optional) list parameter. Any idea why?
Or is there any other method I can use to get unique IDs for my query layer?
I am not allowed to create my view directly in the database.
I use ArcGIS 10.3.1. and the underlying database is Oracle 12c. All ID fields are integers (NUMBER(10, 0)).