How to Declare User-Defined Handlers

The following examples show how to declare a user-defined handler in ESQL/COBOL:

     EXEC SQL INCLUDE SQLCA END-EXEC.
...
PROCEDURE DIVISION.
BEGIN.

     EXEC SQL CONNECT dbname END-EXEC.

*    Call "C" routine to set error handler on.
*    ErrProg will be called whenever an error occurs.
     CALL "ErrTrap".
     ...
     ...

*    Suppress display of error number (don't call ErrProg) for next statement by
*    turning error handler off.
     EXEC SQL SET_SQL(ERRORHANDLER = 0) END-EXEC.
     EXEC SQL .....
*    Turn error handler back on. ErrProg will now be
*    called again whenever an error occurs.
     CALL "ErrTrap".
              ...
END PROGRAM TEST-PROG.

       IDENTIFICATION DIVISION.
       PROGRAM-ID. ErrProg.
       ENVIRONMENT DIVISION.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       EXEC SQL INCLUDE SQLCA END-EXEC.

       EXEC SQL BEGIN DECLARE SECTION END_EXEC.
       01 errnum    PIC S9(9) USAGE DISPLAY.
       EXEC SQL END DECLARE SECTON END-EXEC.
       PROCEDURE DIVISION.
       BEGIN.

              EXEC SQL INQUIRE_SQL(:errnum = ERRORNO) END-EXEC.
              DISPLAY "Errnum is " errnum.
       END PROGRAM ErrProg.

The following example is an embedded SQL/C routine that declares ErrProg to the Ingres runtime system:

ErrTrap()
{
extern int ErrProg();
EXEC SQL SET_SQL (ERRORHANDLER = ErrProg);
}

         EXEC SQL INCLUDE SQLCA END-EXEC.
         01 error_func PIC S9(9) USAGE COMP VALUE EXTERNAL
         ErrProg.
...

PROCEDURE DIVISION
BEGIN.
       EXEC SQL CONNECT dbname END-EXEC.
       EXEC SQL SET_SQL (ERRORHANDLER = error_func)
             END-EXEC.
       . . .
END PROGRAM Test-prog.
IDENTIFICATION DIVISION.
PROGRAM-ID. ErrProg.
ENVIRONMENT DIVISION.
DATA DIVISION.

WORKING-STORAGE SECTION.
              EXEC SQL INCLUDE SQLCA END-EXEC.
              EXEC SQL BEGIN DECLARE SECTION END-EXEC.
                              01 errnum PIC S9(9) USAGE DISPLAY.
                              EXEC SQL END DECLARE SECTION END-EXEC.
PROCEDURE DIVISION.
BEGIN.

      EXEC SQL INQUIRE_SQL (:errnum = ERRORNO) END-EXEC.
      DISPLAY "Errnum is " errnum.
END PROGRAM ErrProg.