BLOB access using PL/SQL or SQL

Question

I have the following script which creates a table and populates it including an employee picture in a BLOB column.
-- * cr_lob.sql *
-- * created by Lloyd R. Weaver *
-- * February 24, 2003 *
Connect SYSTEM/MANAGER
-- * Initial cleanup *
DROP USER ORA4 CASCADE;
DROP TABLESPACE MEDIUM_VOL_DATA INCLUDING CONTENTS CASCADE CONSTRAINTS;
DROP TABLESPACE LARGE_OBJECT_INDEX INCLUDING CONTENTS CASCADE CONSTRAINTS;
DROP TABLESPACE LARGE_OBJECT_DATA INCLUDING CONTENTS CASCADE CONSTRAINTS;
DROP DIRECTORY PHOTOS;
HOST ERASE C:\ORACLE\ORADATA\ORCL\MED_VOL_DATA_F1.DBF
HOST ERASE C:\ORACLE\ORADATA\ORCL\LRG_OBJ_INDX_F1.DBF
HOST ERASE C:\ORACLE\ORADATA\ORCL\LRG_OBJ_DATA_F1.DBF
-- * Create user account for demo *
CREATE USER ORA4 IDENTIFIED BY ORA4
DEFAULT TABLESPACE USERS
QUOTA UNLIMITED ON USERS
QUOTA 0 ON SYSTEM;
GRANT DBA TO ORA4;
CONNECT ORA4/ORA4
-- * Step 1: Create Tablespaces for LOB scenario *
CREATE TABLESPACE MEDIUM_VOL_DATA
DATAFILE 'C:\ORACLE\ORADATA\ORCL\MED_VOL_DATA_F1.DBF' SIZE 2M
AUTOEXTEND ON NEXT 1M MAXSIZE UNLIMITED
DEFAULT STORAGE (INITIAL 10K NEXT 10K PCTINCREASE 0 MAXEXTENTS 100)
EXTENT MANAGEMENT DICTIONARY;
CREATE TABLESPACE LARGE_OBJECT_INDEX
DATAFILE 'C:\ORACLE\ORADATA\ORCL\LRG_OBJ_INDX_F1.DBF' SIZE 2M
AUTOEXTEND ON NEXT 1M MAXSIZE UNLIMITED
DEFAULT STORAGE (INITIAL 10K NEXT 10K PCTINCREASE 0 MAXEXTENTS 100)
EXTENT MANAGEMENT DICTIONARY;
CREATE TABLESPACE LARGE_OBJECT_DATA
DATAFILE 'C:\ORACLE\ORADATA\ORCL\LRG_OBJ_DATA_F1.DBF' SIZE 20M
AUTOEXTEND ON NEXT 5M MAXSIZE UNLIMITED
DEFAULT STORAGE (INITIAL 1M NEXT 1M PCTINCREASE 0 MAXEXTENTS 100)
EXTENT MANAGEMENT DICTIONARY;
-- * Step 2: Create a table with BLOB column and add primary key constraint *
CREATE TABLE LTI_INSTRUCTOR
(INST_ID NUMBER(4)
,INST_LNAME VARCHAR2(25)
,INST_FNAME VARCHAR2(12)
,INST_PHOTO BLOB DEFAULT EMPTY_BLOB())
LOB (INST_PHOTO) STORE AS INST_PHOTO_DATA_SEG
(TABLESPACE LARGE_OBJECT_DATA STORAGE (INITIAL 1M NEXT 1M PCTINCREASE 0)
DISABLE STORAGE IN ROW
CHUNK 10 NOCACHE NOLOGGING
PCTVERSION 10
INDEX INST_PHOTO_INDEX_SEG
(TABLESPACE LARGE_OBJECT_INDEX STORAGE (INITIAL 100K NEXT 100K PCTINCREASE 0)))
TABLESPACE MEDIUM_VOL_DATA STORAGE (INITIAL 100K NEXT 100K PCTINCREASE 0);
ALTER TABLE LTI_INSTRUCTOR
ADD CONSTRAINT LTI_INSTRUCTOR_PK
PRIMARY KEY (INST_ID);
-- * Step 3: Create the directory for the photos *
CREATE DIRECTORY PHOTOS AS 'C:\InstructorPhotos';
-- * Step 4: Create the procedure to insert a row into the table including the photo *
CREATE OR REPLACE PROCEDURE INSERT_LTI_INSTRUCTOR
(V_INST_ID IN LTI_INSTRUCTOR.INST_ID%TYPE
,V_INST_LNAME IN LTI_INSTRUCTOR.INST_LNAME%TYPE
,V_INST_FNAME IN LTI_INSTRUCTOR.INST_FNAME%TYPE
,V_PHOTO_FILE IN VARCHAR2) IS
FILELOC BFILE;
LOCBLOB BLOB;
LEN INT;
E_BLOB BLOB;
BEGIN
FILELOC := BFILENAME('PHOTOS', V_PHOTO_FILE);
E_BLOB := EMPTY_BLOB();
INSERT INTO LTI_INSTRUCTOR VALUES (V_INST_ID, V_INST_LNAME, V_INST_FNAME, E_BLOB)
RETURNING INST_PHOTO INTO LOCBLOB;
DBMS_LOB.FILEOPEN(FILELOC);
LEN := DBMS_LOB.GETLENGTH(FILELOC);
DBMS_LOB.LOADFROMFILE(LOCBLOB,FILELOC,LEN);
DBMS_LOB.FILECLOSEALL();
COMMIT;
EXCEPTION
WHEN OTHERS THEN
RAISE_APPLICATION_ERROR(-20999, SQLERRM);
END;
-- * Step 5: Create a function to return the lenth of the BLOB field by reading it *
CREATE OR REPLACE FUNCTION INST_PHOTO_SIZE
(V_INST_ID LTI_INSTRUCTOR.INST_ID%TYPE)
RETURN NUMBER
IS
SRCH_LOB BLOB;
BUFFER RAW(16384);
AMOUNT BINARY_INTEGER := 16384;
POS INTEGER := 1;
COUNTER INTEGER := 1;
TOTAL_BYTES INTEGER;
BEGIN
SELECT INST_PHOTO
INTO SRCH_LOB
FROM LTI_INSTRUCTOR
WHERE INST_ID = V_INST_ID;
IF SRCH_LOB IS NOT NULL THEN
     LOOP
DBMS_LOB.READ (SRCH_LOB, AMOUNT, POS, BUFFER);
POS := POS + AMOUNT;
COUNTER := COUNTER + 1;
END LOOP;
ELSE
TOTAL_BYTES := NULL;
END IF;
RETURN TOTAL_BYTES;
EXCEPTION
WHEN NO_DATA_FOUND THEN
TOTAL_BYTES := POS;
RETURN TOTAL_BYTES;
WHEN OTHERS THEN
RAISE_APPLICATION_ERROR(-20999, SQLERRM);
END;
-- * Step 6: Insert rows including photos into table and confirm data entry *
-- * Note: The photos are in the directory (case sensitive) defined in Step 3. *
EXECUTE INSERT_LTI_INSTRUCTOR(1001,'WEAVER','LLOYD','Lloyd.JPG');
EXECUTE INSERT_LTI_INSTRUCTOR(1002,'EVIL','LLOYD','lloyd-evil.jpg');
EXECUTE INSERT_LTI_INSTRUCTOR(1003,'SHELTON','CONNIE','Connie.JPG');
EXECUTE INSERT_LTI_INSTRUCTOR(1004,'SMITH','DOUG','Doug.JPG');
SELECT INST_ID, INST_LNAME, INST_FNAME, INST_PHOTO_SIZE(INST_ID) PHOTO_BYTES
FROM LTI_INSTRUCTOR;
I want to display the BLOB column on a asp web page but cannot get it to recognize the BLOB column back as a picture. Since this is being used to demo uses of PL/SQL, I would like to keep it all as SQL or PL/SQL
The asp page looks like the following...it selects the row from the table based on the instructor selected from another pane. (ORCLConnectORA4 is an ODBC connection)
<%
Const lcDBName = "ORCLConnectORA4"
%>
<html>
<body text="#000000" bgcolor="#FFFFFF" link="#CC9900" vlink="#CC9900" alink="#EE1111">
<%
lID=Request.form("EmployeeSelection")
Set lConn = Server.CreateObject("ADODB.Connection")
lConn.ConnectionString = "DSN=" & lcDBName & ";UID=ORA4;PWD=ORA4"
lConn.Open
lSQL = "SELECT INST_FNAME, INST_LNAME, INST_PHOTO from LTI_INSTRUCTOR where INST_ID = " & lID
Set lRS = lConn.Execute(lSQL)
%>
<table border="1" cellspacing="0" width=80% align="center">
<%
lRows = 0
On Error Resume Next
lRS.MoveFirst
lRows = lRows + 1
lFNAME = lRS.Fields("INST_FNAME").Value
lLNAME = lRS.Fields("INST_LNAME").Value
lPHOTO = lRS.Fields("INST_PHOTO").Value
     lConn.Execute(lSQL)
%>
<tr>
<td <%=lBGColor%> align="left" bgcolor="#990000" width="150"><font color="#FFFFFF" size="4"><strong><small>Employee ID</small></strong></font></td>
<td <%=lBGColor%> align="left" bgcolor="#CCCCCC"><b><font size="4" color="#990000"><small><%=lID%>
</small></font></b></td>
</tr>
<tr>
<td <%=lBGColor%> align="left" bgcolor="#990000" width="150"><font color="#FFFFFF" size="4"><strong><small>First Name</small></strong></font></td>
<td <%=lBGColor%> align="left" bgcolor="#CCCCCC"><b><font size="4" color="#990000"><small><%=lFNAME%>
</small></font></b></td>
</tr>
<tr>
<td <%=lBGColor%> align="left" bgcolor="#990000" width="150"><font color="#FFFFFF" size="4"><strong><small>Last Name</small></strong></font></td>
<td <%=lBGColor%> align="left" bgcolor="#CCCCCC"><b><font size="4" color="#990000"><small><%=lLNAME%>
</small></font></b></td>
</tr>
<tr>
<td align="left"><%=lPHOTO%></td>
</tr>
<%
lRS.Close
lConn.Close
%>
</table>
</body>
</html>

Answer 1

Hi,
You've posted this to the web services list. Do you want to use a web service to retrieve the BLOB?
You might want to repost this to another of the forums
rgds
Susan Duncan