The TRIG_OPER and TRIG_RETC Variables and TRIG_LIST Working List

When a trigger function is invoked it receives 2 things from the invoker:

TRIG_OPER

TRIG_OPER: is an A(6) field which must be defined in the data dictionary. The content of this field defines what database operation has, or is about to be, performed. Refer to What Codes Are Passed in TRIG_OPER to the Trigger? for details.

TRIG_LIST

TRIG_LIST: is a 2 entry working list containing 0,1 or 2 entries. The number of entries passed depends upon the database operation being performed. Refer to How Many Entries Are Passed in the TRIG_LIST? for details.

You must define TRIG_LIST as a working list with 2 entries but you must not define any fields within it. The required fields are automatically defined by the RDML compiler.

If your trigger is for field #CUSTNO then the single field #CUSTNO is automatically defined in the list just as if you had typed in:

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Only use the list operations SELECTLIST, GET_ENTRY and UPD_ENTRY against the list TRIG_LIST. Only ever issue UPD_ENTRY operations against entry number 1. When a trigger function terminates it returns 2 things to the invoker:

TRIG_RETC

It : is an A(2) field which must be defined in the data dictionary. At the point of return it must be set to "OK", "ER", and in some situations, "VE". See the following sections for more details of the meaning and use of these return codes.

TRIG_LIST

It : is the 2 entry working list containing 0,1 or 2 entries previously described. You may alter the data in the first entry passed by using the UPD_ENTRY command. If you do this in a "before" operation then you will actually alter the data that is inserted or updated into the table.

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It is strongly recommended that you do not use this facility to "communicate" between serially invoked trigger functions.

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