Triggers and their relationship to CL commands

 

Triggers interact with CL commands in several ways.

Save/Restore Base File (SAVOBJ/RSTOBJ)

• The Save/Restore function will not search for the trigger program during save/restore time. It is your responsibility to manage the program. During run time, if the system has not restored the trigger program, the system returns a hard error with the trigger program name, physical file name, and trigger event.

• If the entire library (*ALL) is saved and the file and all trigger programs are in the same library and they are restored to a different library, then all the trigger program names are changed in the file to reflect the new library.

Save/Restore Trigger Program (SAVOBJ/RSTOBJ)

• If you restore the trigger program in a different library, the change operation fails because the trigger program is not in the original library. The error returns the trigger program name, physical file name, and trigger event information.There are two ways to recover in this situation:

  • Restore the trigger program to the same library

  • Create a new trigger program with the same name in the new library

Delete File (DLTF)

• If a file is deleted, the association between this file and its trigger programs are removed. For system triggers, the trigger programs remain on the system.

Copy File (CPYF)

• If a to-file associates with an insert trigger, each inserted record calls the trigger program.

• If a to-file associates with a delete trigger program and the CPYF command specifies MBROPT(*REPLACE), the copy operation fails.

• Copy with CREATE(*YES) does not propagate the trigger information

Create Duplicate Object (CRTDUPOBJ)

If TRG(*NO) is specified, triggers will not be duplicated in the new file. If TRG(*YES) is specified, triggers will be duplicated. The following rules describe how triggers are duplicated:

• When a physical file and its trigger program are originally in the same library, the trigger program library will always be changed to the new library, even if the trigger program does not exist in the new library. In addition, the following rules apply:

  • If the CRTDUPOBJ command is duplicating both the physical file and its trigger program to a new library, then the new trigger program will be associated with the new physical file.

  • If the CRTDUPOBJ command is duplicating only the physical file, then the trigger program with the same program name in the TO library will be associated with the new physical file. This is true even if there is no trigger program by that name in the TO library. The library of the trigger program will be changed.

  • If the CRTDUPOBJ command is duplicating only the trigger program, then the new trigger program will not be associated with any physical files.

• When a physical file and its trigger program are originally in different libraries:

  • The old trigger program will be associated with the new physical file. Even if the new physical file is duplicated to the same library as the trigger program, the old trigger program will still be associated with the new physical file.

• A trigger program cannot be added if the program is in the QTEMP library. For database files, the CRTDUPOBJ command attempts to locate the trigger program in the TO library. If the CRTDUPOBJ command is used with QTEMP specified as the new library, CRTDUPOBJ attempts to create as much of the object as possible. The file is created, but the trigger cannot be added, so the file remains in QTEMP without a member.

Clear Physical File Member (CLRPFM)

• If the physical file is associated with a delete trigger, the CLRPFM operation fails.

Initialize Physical File Member (INZPFM)

• If the physical file is associated with an insert trigger, the INZPFM operation fails.

FORTRAN Force-End-Of-Data (FEOD)

• If the physical file is associated with a delete trigger, the FEOD operation fails.

Apply Journaled Changes or Remove Journaled Changes (APYJRNCHG/RMVJRNCHG)

• If the physical file is associated with any type of trigger, the APYJRNCHG and RMVJRNCHG operations do not call the trigger program. Therefore, make sure to have all the files within the trigger program journaled. Then, when using the APYJRNCHG or RMVJRNCHG command, make sure to specify all of these files. This ensures that all the physical file changes for the application program and the trigger programs are consistent.

  If any trigger program functions do not relate to database files and cannot be explicitly journaled, send journal entries to record relevant information. Use the Send Journal Entry (SNDJRNE) command or the Send Journal Entry (QJOSJRNE) API. Use this information during database file recovery to ensure consistency.

 

Parent topic:

Triggering automatic events in your database