Need help on a trigger

Question

I am using Oracle 9i. I tried to take a lot of the other fields out of this trigger so that the real problem could be seen. I am trying to create a trigger that cleans up a string field, then verifies the new character with a field in another table. Once they are equal it will grab that ID number and place it in required field. Below is what I have so far for the trigger.
Table 1
SP_id INTEGER
TT_id INTEGER
LEGACY VARCHAR2
Table 2
SID NUMBER (10)
UID VARCHAR2
DESCRIPTION VARCHAR2
Table 3
T_id INTEGER
NAME VARCHAR2
CREATE OR REPLACE TRIGGER ABC
AFTER INSERT OR UPDATE
ON 2
REFERENCING NEW AS NEW OLD AS OLD
FOR EACH ROW
BEGIN
IF (INSERTING)
THEN
INSERT INTO 1
(SP_id,
TT_id,
LEGACY)
VALUES (XXX_seq.NEXTVAL,
substr(:New.description, 1, instr(translate(:New.description, '1234567890', '**********'),'*')-2) ,
SUBSTR (:NEW.uid, 1, 30));
END IF;
END ABC;
I need to take the parsed character field [substr(:New.description, 1, instr(translate(:New.description, '1234567890', '**********'),'*')-2) ,]
then verify its value with table 3's NAME field. Once the correct name is found I need to grab the table3.T_id and place it in the TT_id in table 1. Should this all be done in a trigger or should I try to create a function that is then called out in the trigger? Any help, advice, or examples would be appreciated.

Answer 1

Below I've done it using two different approaches:
1) using triggers
2) using an api
I prefer using an api for mainly for performance reasons, but it's your call
SQL> create table t1
  2  ( sp_id integer
  3  , tt_id integer
  4  , legacy varchar2(100)
  5  )
  6  /
Tabel is aangemaakt.
SQL> create table t2
  2  ( sid number (10)
  3  , u_id varchar2 (100)
  4  , description varchar2(100)
  5  )
  6  /
Tabel is aangemaakt.
SQL> create table t3
  2  ( t_id integer
  3  , name varchar2(100)
  4  )
  5  /
Tabel is aangemaakt.
SQL> create sequence xxx_seq start with 1 increment by 1
  2  /
Reeks is aangemaakt.
SQL> create or replace trigger abc
  2  after insert on t2
  3  for each row
  4  declare
  5    l_t3_id t3.t_id%type;
  6  begin
  7    begin
  8      select t3.t_id
  9        into l_t3_id
10        from t3
11       where t3.name = substr(:new.description, 1, instr(translate(:new.description, '1234567890', '**********'),'*')-2)
12      ;
13    exception
14    when no_data_found
15    then
16      null;
17    when too_many_rows
18    then
19      null;
20    end
21    ;
22    insert into t1
23    ( sp_id
24    , tt_id
25    , legacy
26    )
27    values
28    ( xxx_seq.nextval
29    , l_t3_id
30    , substr (:new.u_id, 1, 30)
31    );
32  end abc;
33  /
Trigger is aangemaakt.
SQL> insert into t3 values (1, 'abc')
  2  /
1 rij is aangemaakt.
SQL> insert into t3 values (2, 'xyz')
  2  /
1 rij is aangemaakt.
SQL> commit
  2  /
Commit is voltooid.
SQL> insert into t2 values (11, '12', 'abc 12345')
  2  /
1 rij is aangemaakt.
SQL> insert into t2 values (13, '14', 'pqr 65432')
  2  /
1 rij is aangemaakt.
SQL> insert into t2 values (15, '16', 'xyza9875123')
  2  /
1 rij is aangemaakt.
SQL> select * from t2
  2  /
       SID U_ID                           DESCRIPTION
        11 12                             abc 12345
        13 14                             pqr 65432
        15 16                             xyza9875123
3 rijen zijn geselecteerd.
SQL> select * from t1
  2  /
     SP_ID      TT_ID LEGACY
         1          1 12
         2            14
         3          2 16
3 rijen zijn geselecteerd.This is the end of the trigger approach.
From here on it's the api approach:
SQL> rollback
  2  /
Rollback is voltooid.
SQL> drop trigger abc
  2  /
Trigger is verwijderd.
SQL> create package t2_dml
  2  as
  3    procedure create_t2_and_t1
  4    ( p_sid         t2.sid%type
  5    , p_u_id        t2.u_id%type
  6    , p_description t2.description%type
  7    );
  8  end t2_dml;
  9  /
Package is aangemaakt.
SQL> create package body t2_dml
  2  as
  3    procedure create_t2_and_t1
  4    ( p_sid         t2.sid%type
  5    , p_u_id        t2.u_id%type
  6    , p_description t2.description%type
  7    )
  8    is
  9      l_t3_id t3.t_id%type;
10    begin
11      insert into t2
12      ( sid
13      , u_id
14      , description
15      )
16      values
17      ( p_sid
18      , p_u_id
19      , p_description
20      );
21      begin
22        select t3.t_id
23          into l_t3_id
24          from t3
25         where t3.name = substr(p_description, 1, instr(translate(p_description, '1234567890', '**********'),'*')-2)
26        ;
27      exception
28      when no_data_found
29      then
30        null;
31      when too_many_rows
32      then
33        null;
34      end
35      ;
36      insert into t1
37      ( sp_id
38      , tt_id
39      , legacy
40      )
41      values
42      ( xxx_seq.nextval
43      , l_t3_id
44      , substr (p_u_id, 1, 30)
45      );
46    end create_t2_and_t1
47    ;
48  end t2_dml;
49  /
Package-body is aangemaakt.
SQL> exec t2_dml.create_t2_and_t1(11,'12','abc 12345')
PL/SQL-procedure is geslaagd.
SQL> exec t2_dml.create_t2_and_t1(13,'14','pqr 65432')
PL/SQL-procedure is geslaagd.
SQL> exec t2_dml.create_t2_and_t1(15,'16','xyza9875123')
PL/SQL-procedure is geslaagd.
SQL> select * from t2
  2  /
       SID U_ID                           DESCRIPTION
        11 12                             abc 12345
        13 14                             pqr 65432
        15 16                             xyza9875123
3 rijen zijn geselecteerd.
SQL> select * from t1
  2  /
     SP_ID      TT_ID LEGACY
         4          1 12
         5            14
         6          2 16
3 rijen zijn geselecteerd.I hope this helps.
Regards,
Rob.