Question

I need to do a trigger but the only difference that I’m trying to do is to get a dynamic value according to ‘:new.COLUMN_NAME’ and ‘:old.COLUMN_NAME’

I’m bringing the columns of a table in a query and after that I run it with a for LOOP ..

this is my trigger:

CREATE OR REPLACE TRIGGER aft_ins_soliccambio
AFTER INSERT OR DELETE OR UPDATE
ON SEG_V_SOLICCAMBIO
REFERENCING OLD AS OLD NEW AS NEW
FOR EACH ROW
DECLARE
   old_col_value   VARCHAR2 (4000);
   new_col_value   VARCHAR2 (4000);
BEGIN
   FOR REC IN (  SELECT OWNER, TABLE_NAME, COLUMN_NAME
                   FROM all_tab_columns
                  WHERE OWNER = 'EUCEDA' AND (TABLE_NAME = 'SEG_V_SOLICCAMBIO')
               ORDER BY column_id)
   LOOP
      EXECUTE IMMEDIATE ' select :new.' || REC.COLUMN_NAME || ' from dual'
               INTO new_col_value;

      pkg_tumi.insert_auditoria ('SEG_V_SOLICCAMBIO',
                                 REC.COLUMN_NAME,
                                 :new.EMPR_IDEMPRESA_N,
                                 fn_get_pk ('SEG_V_SOLICCAMBIO', 1),
                                 fn_get_pk ('SEG_V_SOLICCAMBIO', 2),
                                 fn_get_pk ('SEG_V_SOLICCAMBIO', 3),
                                 fn_get_pk ('SEG_V_SOLICCAMBIO', 4),
                                 fn_get_pk ('SEG_V_SOLICCAMBIO', 5),
                                 fn_get_pk ('SEG_V_SOLICCAMBIO', 6),
                                 1,
                                 '',
                                 new_col_value,
                                 SYSDATE,
                                 NULL);
   END LOOP;
END;

when I compile the trigger it doesn’t throw any error but when I try inserting a new value in the table that I’m making the trigger it throws this error:

ORA-01008: no todas las variables han sido enlazadas
ORA-06512: en “EUCEDA.AFT_INS_SOLICCAMBIO”, línea 10
ORA-04088: error durante la ejecución del disparador ‘EUCEDA.AFT_INS_SOLICCAMBIO’

Checking the problem I realized that the problem is between ‘EXECUTE IMMEDIATE ..’ but I see that is because of :new.’dynamic_column’ is not recognized. Please Help! I’m many hours with this problem and I can’t solve it.

Thanks and sorry for my english.

Answer 1

:new and :old within triggers are somewhat inflexible. I don’t know of any way of using dynamic SQL to do what you’re attempting to do with your EXECUTE IMMEDIATE. I suspect it’s not possible.

I’m afraid the only alternatives I know about are somewhat laborious. One such alternative is to replace the EXECUTE IMMEDIATE with a CASE expression such as the following:

    new_col_value := CASE REC.COLUMN_NAME
                       WHEN 'COLUMN_1' THEN :new.column_1
                       WHEN 'COLUMN_2' THEN :new.column_2
                       WHEN 'COLUMN_3' THEN :new.column_3
                       ...
                     END;

It might be possible to run a suitable SQL statement to generate all of the WHEN ... THEN ... lines within this CASE statement rather than typing them all in yourself.