Answer
Specify which SQL columns should serve as the primary key directly when creating (or editing) the IAL — there's a PK Index setting where the relevant columns from your underlying query can be marked as the object's primary key, matching whatever combination of columns uniquely identifies a row in your source query (for a view like Inventory Part In Stock, that's typically the same multi-column combination — part, contract, configuration, location, lot/batch, serial, and so on — that makes up the underlying table's own primary key).