a.wacknitz@francotyp.com writes:

my question is what type or value is returned by a ZSQL method that is invoked from Python? ZSQL methods return "Shared.DC.ZRDB.Results.Results" instances. Such an instance essentially behaves like a sequence of objects each describing one result row. These objects have been set up such that a column value can be accessed as attribute with the column name. Thus, "results[i].column" gives the value of "column" of the i.th row.

How to determine, how "Null" values are recognized, is less a Zope than a database adapter question. I would expect, that most (if not all) database adapters will map SQL Null to None. However, even some well established SQL databases do not treat Null standards-conform but represent it as the empty string. Then, the database adapter has no chance to map this to None but must use '', too. Dieter