ON DB_CHANGE action

Declaration
ON DB_CHANGE tableIdent GOTO [procName [PRTY prtyIdent]|  NONE]
Parameters
tableIdentinIdentifier of the object of the Table type.
procNameinName of RPC procedure in ESL script.
prtyIdentinOptional identifier of the Int type. A priority when calling RPC.
Description
Action defines a procedure (by the name procName) which will be called when the values in database table are changed. This change is identified by the D2000 DbManager ON DB_CHANGE which is the only one process executing a database operations in the D2000 system. If it identifies some change, it will automatically generate a command for calling the registered RPC procedure.

The keyword PRTY enables to set the priority of executing registered RPC procedure. The priority is defined by the parameter prtyIdent after PRTY.

Action ON DB_CHANGE tableIdent GOTO NONE will cancel the calling of procedure when the table is being changed. One table can have (in context of ESL script instance) only one procedure for handle of its change. That is why the repeated registration of handle for one table will cause ESL run-time error and the script failed.

The declaration of the procedure procName must be following:
 
 RPC PROCEDURE ProcName (IN INT _dbTable, IN INT _actionId)
 END ProcName

RPCX can be used instead of RPC.

The value of formal parameter _actionId can be one of the following options:

_actionId0Monitoring of the table has started successfully.
_actionId1Initialization of table monitoring failed because of one of the following reasons:
  • the D2000 DbManager process does not run,
  • the identifier tableIdent is not the identifier of object of Table type,
  • the monitoring of table was interrupted unexpectedly, e.g. D2000 DbManager failed.
_actionId10D2000 DbManager is executing the action DB_REFRESH_TABLE or a structure definition configured on object of Table type has been saved.
_actionId11D2000 DbManager has finished the operation DB_*, DBS_* PG_* or some operation has been executed over the table from process D2000 HI by user interface.
If the modification are executed within the database transaction (DB_TRANS_OPEN ...), D2000 DbManager generates a message about the change of table when the changes are being confirmed (DB_TRANS_COMMIT).
_actionId12The table has been deleted from configuration of application.
_actionId13The active instance of the D2000 DbManager process  changed its status to passive or in redundancy the D2000 Server to which the D2000 DbManager process is connected changed its status from HOT to SBS. It is necessary to re-register at new active instance of the D2000 DbManager process via action ON DB_CHANGE.
Note: When switching the active instance or during D2000 redundancy switch (when the D2000 DbManager process becomes passive), all the transactions are closed, all database operations are terminated and all handles are invalidated. Therefore it is necessary to repeat all of the initialization sequences of scripts on a new active instance (opening the databases, tables etc.).

Related pages:

Script actions

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