DDL to execute ?

Question

Hi
oracle 10.2.0.1.0
I have created a view on table as
create table try_table ( sno number);
create or replace view try_table_vw as select * from try_table;When I alter the table and select/ desc the view then new coluymn is nt reflected until I recreate the view .
select * from try_table_vw;
desc try_table_vw;
alter table try_table add ( name varchar2(20));Is it that when ever DDL changes I need to create or replace the view definition ???

Answer 1

SQL> DESC emp_test
Name                                      Null?    Type
EMPNO                                              NUMBER(4)
ENAME                                              VARCHAR2(10)
JOB                                                VARCHAR2(9)
MGR                                                NUMBER(4)
HIREDATE                                           DATE
SAL                                                NUMBER(7,2)
COMM                                               NUMBER(7,2)
DEPTNO                                             NUMBER(2)
SQL> CREATE OR REPLACE VIEW emp_test_view AS SELECT * FROM emp_test;
View created.
SQL> /* Now checking My view status */
SQL> SELECT object_name,status FROM user_objects
  2  WHERE object_name='EMP_TEST_VIEW';
OBJECT_NAME
STATUS
EMP_TEST_VIEW
VALID
SQL> /* Although, I have created it as SELECT * FROM ...., I want to see
DOC>    How Oracle has stored the definition */
SQL> set line 1000
SQL> set long 1000000
SQL> SELECT view_name,text FROM user_views
  2  WHERE view_name='EMP_TEST_VIEW';
VIEW_NAME                      TEXT
EMP_TEST_VIEW                  SELECT "EMPNO","ENAME","JOB","MGR","HIREDATE","SAL","COMM","DEPTNO" FROM emp_tes
                               t
SQL> /* So, it has stored it as all the column names, not as SELECT *..... */
SQL> /* So, If I add a column to this table, this definition will not be updated autometicaly
DOC>    and SELECT * FROM view_name will show all the old columns */
SQL> ALTER TABLE emp_test ADD dummy VARCHAR2(1);
Table altered.
SQL> desc emp_test
Name                                                                                                                  
EMPNO                                                                                                                 
ENAME                                                                                                                 
JOB                                                                                                                   
MGR                                                                                                                   
HIREDATE                                                                                                              
SAL                                                                                                                   
COMM                                                                                                                  
DEPTNO                                                                                                                
DUMMY                                                                                                                 
SQL> SELECT view_name,text FROM user_views
  2  WHERE view_name='EMP_TEST_VIEW';
VIEW_NAME                      TEXT
EMP_TEST_VIEW                  SELECT "EMPNO","ENAME","JOB","MGR","HIREDATE","SAL","COMM","DEPTNO" FROM emp_tes
                               t
SQL> SELECT * FROM emp_test_view WHERE rownum<3;
     EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM     DEPTNO
      7369 SMITH      CLERK           7902 17-DEC-80        800                    20
      7499 ALLEN      SALESMAN        7698 20-FEB-81       1600        300         30
SQL> /* Now, again We are re-creating the view */
SQL>  CREATE OR REPLACE VIEW emp_test_view AS SELECT * FROM emp_test;
View created.
SQL> SELECT view_name,text FROM user_views
  2  WHERE view_name='EMP_TEST_VIEW';
VIEW_NAME                      TEXT
EMP_TEST_VIEW                  SELECT "EMPNO","ENAME","JOB","MGR","HIREDATE","SAL","COMM","DEPTNO","DUMMY" FROM
                                emp_test
SQL> /* Now, you can see the definition got updated and successive SELECETs can retrive the new column value */
SQL>