CREATE-TRIGGER

The CREATE-TRIGGER command is used to specify the database events for which the trigger subroutine is called.

 

COMMAND SYNTAX

CREATE-TRIGGER -Options FileName {triggername|*} subroutine

 

SYNTAX ELEMENTS

FileName can reference either a jBASE hashed file or a directory.

triggername must be * or one of the nine database events: POSTOPEN, PREREAD, POSTREAD, PREWRITE, POSTWRITE, PREDELETE, POSTDELETE, PRECLEAR, POSTCLEAR. If * is specified then the trigger subroutine will be called for each of the nine database events.

The valid options for CREATE-TRIGGER are:

Option Name Explanation
-a or (A) amend flag subroutine can amend the record
-d or (D) debug flag subroutine can be debugged
-t or (T) terminate flag subroutine terminates update
-o or (O) overwrite flag overwrite any existing definitions

subroutine is the name of a jBC subroutine. Also see Trigger API.

 

NOTES

CREATE-TRIGGER can be run multiple times for the same file. If a trigger has already been defined for the specified event then the overwrite flag must be used to effect the change.

 

EXAMPLES

CREATE-TRIGGER BP POSTOPEN SUBBPOPEN
The subroutine SUBBPOPEN will be called immediately after the BP file is successfully opened by any jBASE process.

CREATE-TRIGGER -o PAYROLL * SUBBP
The subroutine SUBBP will be called for every database event to the PAYROLL file. Existing trigger definitions will be overwritten.

TRIGGERS