Photographs
and pictures and Oracle BLOB data are easy to add to a Oracle table.
There are two ways to load BLOBs and CLOBs into the database. The first
method uses PL/SQL and the DBMS_LOB package and the BFILE datatype to
transfer external LOB files into the database internal LOB structures.
The second uses the Oracle Call Interface (OCI) to perform the same
function. Here, we will use the first method . For inserting an image,
we follow the folowing steps :
Step 1 : First, we need to create a directory on the database (which is mapped to a directory in the server's filesystem). The user must be granted the create any directory privilege.
SQL>create directory photo_dir as 'c:\photo_dir' ;
Directory created.
Step 2 : Then we need to create a table which is used by procedure to insert the image in our table . Here we have to use a BLOB to insert the image .
SQL> create table temp_photo
(
ID NUMBER(3) NOT NULL,
PHOTO_NAME VARCHAR2(50),
PHOTO BLOB
);
Table created.
Step 3 : Now let's write the procedure to insert the image in the table above.
SQL> create or replace PROCEDURE load_file (
p_id number,
p_photo_name in varchar2) IS
src_file BFILE;
dst_file BLOB;
lgh_file BINARY_INTEGER;
BEGIN
src_file := bfilename('PHOTO_DIR', p_photo_name);
-- insert a NULL record to lock
INSERT INTO temp_photo
(id, photo_name, photo)
VALUES
(p_id , p_photo_name ,EMPTY_BLOB())
RETURNING photo INTO dst_file;
-- lock record
SELECT photo
INTO dst_file
FROM temp_photo
WHERE id = p_id
AND photo_name = p_photo_name
FOR UPDATE;
-- open the file
dbms_lob.fileopen(src_file, dbms_lob.file_readonly);
-- determine length
lgh_file := dbms_lob.getlength(src_file);
-- read the file
dbms_lob.loadfromfile(dst_file, src_file, lgh_file);
-- update the blob field
UPDATE temp_photo
SET photo = dst_file
WHERE id = p_id
AND photo_name = p_photo_name;
-- close file
dbms_lob.fileclose(src_file);
END load_file;
/
Step 4 : We can test it from SQL*Plus
SQL> execute load_file(1,'rdht.jpg') ;
Note : Remember that the file rdht.jpg should exist in the server's 'c:\photo_dir' directory .
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