- Application Portability

As in any application that uses SQL-specific features, porting requires additional evaluation to null data usage. This is especially required for porting a PROIV function to a non-SQL environment.

Some issues arise when moving a pre-Version 3 application that is not sensitive to null data fields to a system with a database that supports null data.

Prior to Version 3, PROIV converted null values to an empty string for ALPHANUMERIC types and to zero for NUMERIC. An application designed to depend on these conversions may now have a compatibility problem.
If a database has no null permissive fields, there should be no problem.
If a database has null permissive fields, the developer must modify the file definitions so that the PROIV definition matches the database definition. In addition, logics must be modified to check a null permissive field for a null value before using it in an expression.

An application, written for PROIV Version 4 that uses null permissive fields can be moved to databases that do not support null data if the application is written with that portability in mind.

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Topic ID: 720010