LANSA provides two methods of defining virtual columns:
LANSA's extended definitions allow you to perform:
RPG or C coded definitions (refer to Virtual Column Derivation in the Technical Reference Guide) may be necessary for complex actions such as:
LANSA trigger functions may also be used to create virtual columns. Trigger functions use RDML and provide an alternate option to using RPG or C for coding the virtual column logic.
A virtual column must be defined in the Repository and may have column and table level validations associated with it. Also, validation rules for the columns used in defining the virtual column are still enforced. A virtual column can be used like any other column in the Repository.
Virtual columns are not part of the real table and cannot be directly used outside of LANSA. Virtual columns are made possible using LANSA's Object Access Module. Client applications using LANSA Open and any applications which use the LANSA Object Access Module can access the LANSA virtual columns.