Inserting Lob value in Oracle

Question

Hi,
I want to know two things
*1-* If I insert a lob value say blob through sql stament as shown below
insert into employee(id,name,picture) values('101','Peter',pic );
Now how value will insert into Oracle table i.e. lob pointer in original table and lob value in either other segment of same tablespace or in segment of different tablespace. I mean is there any internal mechanism which Oracle handles or developer/dba has to take care of it. Like I want to create a separate Lob segment for picture and want to insert original lob value in it. How can I achieve this.
*2-*If I'm using DBMS_LOB package for insertind data in ltable containg lob clolums. Then is it necessary to first initialize lob cloumn and then insert value in it.
Looking for guidence .
Regards,
Abbasi

Answer 1

You can NOT insert a BLOB like insert into employee(id,name,picture) values('101','Peter',pic );, You can try it yourself and check!.
If the column is of BFILE then atleast you need something like insert into employee(id,name,picture) values('101','Peter',BFILENAME('MY_DIR','pic.jpg' );To load/insert a BLOB you need DBMS_LOB. One example may be....
SQL> CREATE TABLE myblob (id NUMBER(2), my_xls BLOB);
Table created.
SQL> CREATE OR REPLACE DIRECTORY TEST_DIR as 'C:\';
Directory created.
SQL> DECLARE
  2    v_src_loc BFILE := BFILENAME('TEST_DIR', 'saubhik.xls');
  3    v_amount  INTEGER;
  4    v_b       BLOB;
  5  BEGIN
  6    DBMS_LOB.OPEN(v_src_loc, DBMS_LOB.LOB_READONLY);
  7    v_amount := DBMS_LOB.GETLENGTH(v_src_loc);
  8    INSERT INTO myblob VALUES (1, EMPTY_BLOB()) RETURNING my_xls INTO v_b;
  9    DBMS_LOB.LOADFROMFILE(v_b, v_src_loc, v_amount);
10    DBMS_LOB.CLOSE(v_src_loc);
11  END;
12  /
PL/SQL procedure successfully completed.
SQL> commit;
Commit complete.