System Generation Compiler › Adding, Modifying, and Deleting Entities › ADD Verb

ADD Verb

The ADD verb adds system and component entity definitions to the data dictionary and associates component entities with the current system. ADD also establishes currency for systems, lines, and physical terminals.

When adding an entity, you can explicitly specify characteristics of the entity and/or you can accept one or more default characteristics. Component entities added to an existing system are not reflected in the executable form of the system until the next successful GENERATE statement for that system. You must generate the system definition before bringing it up.

How the Compiler Handles ADD Requests

The system generation compiler responds to ADD requests, as follows:

• In response to an ADD SYSTEM request, the compiler creates a system source record. The system object record is not created until the compiler successfully processes a GENERATE statement.
• In response to an ADD request for a component entity that does not exist in the data dictionary, the compiler creates both a source record for the entity and an object record that associates the entity with the current system.
• In response to an ADD request for a component entity that already exists in the data dictionary but that is not associated with the current system, the compiler creates an object record that associates the entity with the current system. If you explicitly specify entity characteristics in the ADD request, the system generation compiler also modifies the source record for the entity. Characteristics not explicitly overridden remain unchanged.

Object Records are Flagged for Update

Object records created in response to ADD requests are flagged for update. These records do not yet contain a copy of the information in the corresponding source records. In response to a GENERATE statement, the system generation compiler copies the information about the entity from the source record to the object record and removes the update flag.

Using DEFAULT IS ON Option

The system generation compiler accepts the ADD verb in reference to an existing system or to a component entity already associated with the current system only if you have specified DEFAULT IS ON in the SET OPTIONS statement. When DEFAULT IS ON has been specified, the system generation compiler changes the ADD verb to MODIFY for existing entities.

Note: For more information and syntax for the SET OPTIONS statement, see SET OPTIONS Statement.

The following table illustrates system generation compiler actions in response to ADD requests.