Processing Empty and NULL Values
In Domino® Enterprise Connection Services (DECS) and in IBM® Lotus Enterprise Integrator® (LEI), empty data in a Notes® rich text or Text field is not set to NULL when it is transferred. It is transferred as "". To set empty data to NULL requires that you write a LotusScript® routine or a stored procedure.
For LEI (but not for Advanced RealTime or DECS) NULL is not equivalent to an empty string or to an empty value such as zero. LEI regards a NULL as an undefined value, one that cannot be compared to other values. This is true for all LEI activities (except Advanced RealTime activities), however, Replication is most sensitive to this issue. LEI Replication occurs whenever LEI performs a comparison between Database A and Database B and encounters mismatches in the comparison fields. For example, a replication will occur if LEI finds a NULL in one database matching a corresponding empty value in another. This can occur frequently with date specifications; for example, if Database A specifies a date and Database B has no data specification. When this occurs, LEI uses SQL syntax to convert NULLS to values that are equivalent across databases.