MDAC 2.5 SDK - OLE DB Programmer's Reference
Appendix C: OLE DB Properties
Property group: Data Source Information
Property set: DBPROPSET_DATASOURCEINFO
Type: VT_I4
Typical R/W: R
Description: Column Definition
A bitmask defining the valid clauses for the definition of a column. The following flag can be set:
DBPROPVAL_CD_NOTNULL—Columns can be created non-nullable. For providers that support the SQL CREATE TABLE statement, this implies that the NOT NULL clause is supported in general. Individual provider data types may or may not support non-nullable behavior, and the consumer should consult the PROVIDER_TYPES schema rowset for more information.