Concate values in Trigger

Question

Hi,
I am trying to store the changed value in my trigger to a variable. It seems that i cant do a concate with a bind variable to a string variable.
Is there any workaround for that?
Attached is a snippet of code.
CREATE OR REPLACE TRIGGER Trigger_Test AFTER UPDATE ON Table_A FOR EACH ROW
DECLARE
strNewVal CHAR(32767):= '' ;
strOldVal CHAR(32767):= '' ;
iFieldsUpdated Number;
new_app_type varchar2(60);
old_app_type varchar2(60);     
BEGIN
IF UPDATING THEN
     IF :OLD.COL_A<>:NEW.COL_B THEN
     strNewVal:=strNewVal ||'<br>Col A = '||:NEW.Col_A;
     strOldVal:=strOldVal ||'<br>Col A = '||:OLD.Col_A;     
     END IF;
     INSERT INTO Table_A_aud
     VALUES(strNewVal, strOldVal);
END IF;
END;

Answer 1

SQL> create table table_a(col_a varchar2(10),
  2  col_b varchar2(10));
Table created.
SQL> create table table_a_aud(col1 varchar2(100),
  2  col2 varchar2(100));
Table created.
SQL> insert into table_a values('test1','test2');
1 row created.
SQL> CREATE OR REPLACE TRIGGER Trigger_Test AFTER UPDATE ON Table_A FOR EACH ROW
  2  DECLARE
  3  strNewVal CHAR(32767):= '' ;
  4  strOldVal CHAR(32767):= '' ;
  5  iFieldsUpdated Number;
  6  new_app_type varchar2(60);
  7  old_app_type varchar2(60);
  8 
  9  BEGIN
10  IF UPDATING THEN
11  IF :OLD.COL_A<>:NEW.COL_B THEN
12  strNewVal:=strNewVal ||'<br>Col A = '||:NEW.Col_A;
13  strOldVal:=strOldVal ||'<br>Col A = '||:OLD.Col_A;
14  END IF;
15 
16 
17  INSERT INTO Table_A_aud
18  VALUES(strNewVal, strOldVal);
19 
20  END IF;
21  END;
22  /
Trigger created.
SQL> UPDATE TABLE_A
  2  SET COL_B = 'test3';
UPDATE TABLE_A
ERROR at line 1:
ORA-06502: PL/SQL: numeric or value error: character string buffer too small
ORA-06512: at "SCOTT.TRIGGER_TEST", line 11
ORA-04088: error during execution of trigger 'LMS.TRIGGER_TEST'
SQL> select * from table_a;
COL_A      COL_B
test1      test2
SQL> CREATE OR REPLACE TRIGGER Trigger_Test AFTER UPDATE ON Table_A FOR EACH ROW
  2  DECLARE
  3  strNewVal CHAR(32767):= '' ;
  4  strOldVal CHAR(32767):= '' ;
  5  iFieldsUpdated Number;
  6  new_app_type varchar2(60);
  7  old_app_type varchar2(60);
  8 
  9  BEGIN
10  IF UPDATING THEN
11  IF :OLD.COL_A<>:NEW.COL_B THEN
12  strNewVal:=strNewVal ||'<br>Col A = '||:NEW.Col_A;
13  strOldVal:=strOldVal ||'<br>Col A = '||:OLD.Col_A;
14  END IF;
15 
16 
17  INSERT INTO Table_A_aud
18  VALUES(strNewVal, strOldVal);
19 
20  END IF;
21  END;
22  .
SQL> ed
Wrote file afiedt.buf
  1  CREATE OR REPLACE TRIGGER Trigger_Test AFTER UPDATE ON Table_A FOR EACH ROW
  2  DECLARE
  3  strNewVal VARCHAR2(32767):= '' ;
  4  strOldVal VARCHAR2(32767):= '' ;
  5  iFieldsUpdated Number;
  6  new_app_type varchar2(60);
  7  old_app_type varchar2(60);
  8  BEGIN
  9  IF UPDATING THEN
10  IF :OLD.COL_A<>:NEW.COL_B THEN
11  strNewVal:=strNewVal ||'<br>Col A = '||:NEW.Col_A;
12  strOldVal:=strOldVal ||'<br>Col A = '||:OLD.Col_A;
13  END IF;
14  INSERT INTO Table_A_aud
15  VALUES(strNewVal, strOldVal);
16  END IF;
17* END;
18  /
Trigger created.
SQL> UPDATE TABLE_A
  2  SET COL_B = 'test3';
1 row updated.
SQL> SELECT * FROM TABLE_A_AUD;
COL1
COL2
<br>Col A = test1
<br>Col A = test1Change the datatype for variables 'strNewVal' and 'strOldVal'.