Use table name in UPDATE statement as variable

Question

Hi All,
I am using ORACLE 9i AIX base. I want to write following procedure:
PROCEDURE update_header (
p_care_msg_nbr IN NUMBER,
p_care_msg_id IN NUMBER,
p_care_msg_gkey IN NUMBER,
p_old_status IN VARCHAR2,
p_new_status IN VARCHAR2
IS
l_table varchar2(50);
BEGIN
l_table := 'CARE_EDI_MESSAGES';
UPDATE '&l_table'
SET status = p_new_status,
changed = sysdate,
changer = user
WHERE care_msg_no = p_care_msg_nbr
AND care_msg_id = p_care_msg_id
AND gkey = p_care_msg_gkey
AND status = p_old_status;
END;
I want to give the table name by passing value in a variable or parameter. Is it the write way or can I do this function in any other way.
Pleae tell me in urgency.
Thanks & Regards
Hassan Raza

Answer 1

This implies that you have several tables with identical or near identical structures, otherwise you will get errors if any of the mentioned columns do not exist in the table passed but ...
You cannot use a substitution variable that way. Oracle will ask for a value when you try to create the procedure, and compile what ever value you supply into the procedure viz.
SQL> CREATE PROCEDURE p AS
  2  l_id NUMBER;
  3  BEGIN
  4     SELECT id INTO l_id FROM &t;
  5  END;
  6  /
Enter value for t: T
old   4:    SELECT id INTO l_id FROM &t;
new   4:    SELECT id INTO l_id FROM T;
Procedure created.
SQL> SELECT text FROM user_source WHERE name = 'P'
  2  ORDER BY line;
TEXT
PROCEDURE p AS
l_id NUMBER;
BEGIN
   SELECT id INTO l_id FROM T;
END;Even if that is the effect you want, note that there are no quotes around the substitution variable in the CREATE statement.
If you want to be able to pass the name of the table to the procedure, then you need to make the table name a parameter, then build the sql statement and execute it using EXECUTE IMMEDIATE. Something more like:
PROCEDURE update_header (p_care_msg_nbr  IN NUMBER,
                         p_care_msg_id   IN NUMBER,
                         p_care_msg_gkey IN NUMBER,
                         p_old_status    IN VARCHAR2,
                         p_new_status    IN VARCHAR2,
                         p_table         IN VARCHAR2) IS
l_sqlstr VARCHAR2(4000);
BEGIN
   l_sqlstr := 'UPDATE '||p_table||' SET status = :b1 '||
               'changed = sysdate, changer = user '||
               'WHERE care_msg_no = :b1 and care_msg_id = :b3 and '||
               'gkey = :b4 and status = :b5';
   EXECUTE IMMEDIATE l_sqlstr
      USING p_new_status, p_care_msg_nbr, p_care_msg_id, p_care_msg_gkey, p_old_status;
END;HTH
John