Using dbms_passthrough to build a view

Question

Gurus,
Can i create a view in oracle to access data frm a MysqlDB using dbms_passthrough. I have created a procedure to get the data from remote system to oracle db using dbms_passthrough but was wondering if this can be done using a view
Edited by: user10600431 on 22-Jan-2009 04:39
Edited by: user10600431 on 22-Jan-2009 05:52

Answer 1

Sure you can, but it has to be function, not procedure. I do not have MySql, but below is an example for MS Access. Table TEST_TBL with two columns ID - number and A - string exists in MS Access database:
SQL> CREATE OR REPLACE
  2    TYPE ACCESS_TEST_TBL_OBJ_TYPE
  3      AS OBJECT(
  4                ID NUMBER,
  5                A  VARCHAR2(50)
  6               )
  7  /
Type created.
SQL> CREATE OR REPLACE
  2    TYPE ACCESS_TEST_TBL_TBL_TYPE
  3      AS TABLE OF ACCESS_TEST_TBL_OBJ_TYPE
  4  /
Type created.
SQL> CREATE OR REPLACE
  2    FUNCTION get_data_from_link
  3      RETURN ACCESS_TEST_TBL_TBL_TYPE
  4      PIPELINED
  5      IS
  6          c  INTEGER;
  7          nr INTEGER;
  8          access_test_tbl_obj ACCESS_TEST_TBL_OBJ_TYPE := ACCESS_TEST_TBL_OBJ_TYPE(NULL,NULL);
  9      BEGIN
10          c := DBMS_HS_PASSTHROUGH.OPEN_CURSOR@MDB;
11          DBMS_HS_PASSTHROUGH.PARSE@MDB(c,'select id,a from test_tbl');
12          LOOP
13            nr := DBMS_HS_PASSTHROUGH.FETCH_ROW@MDB(c);
14            EXIT WHEN nr = 0;
15            DBMS_HS_PASSTHROUGH.GET_VALUE@MDB(c,1,access_test_tbl_obj.id);
16            DBMS_HS_PASSTHROUGH.GET_VALUE@MDB(c,2,access_test_tbl_obj.a);
17            PIPE ROW(access_test_tbl_obj);
18          END LOOP;
19          DBMS_HS_PASSTHROUGH.CLOSE_CURSOR@MDB(c);
20          RETURN;
21  END;
22  /
Function created.Now you can issue SELECT against the function:
SQL> SELECT  *
  2    FROM  TABLE(get_data_from_link)
  3  /
        ID A
         1 testOr create a view and select from it:
SQL> CREATE OR REPLACE
  2    VIEW ACCESS_TEST_TBL_VW
  3      AS
  4        SELECT  *
  5          FROM  TABLE(get_data_from_link)
  6  /
View created.
SQL> SELECT  *
  2    FROM  ACCESS_TEST_TBL_VW
  3  /
        ID A
         1 test
SQL>