Display a BLOB data from Oracle in the browser

Question

Hello,
I am trying to display Oracle BLOB(ie ORDSYS.ORDVIR) directly in the browser using ASP.
It is working in SQL Server, but Oracle seems to be giving a problem...
The code written in ASP is as follows :
<%
'Clear out the existing HTTP header Response.Expires = 0
Response.Buffer = TRUE
Response.Clear
' Change the HTTP header to reflect that an image is being passed.
Response.ContentType = "image/jpeg"
Set cn = Server.CreateObject("ADODB.Connection")
cn.Open "UID=cbir;PWD=cbir;DSN=trying"
' Here thumbnaildata is of type ORDSYS.ORDVIR
SQLQuery = "SELECT thumbnaildata from image where imagekey='1.JPG'"
set rsBlob = cn.Execute(SQLQuery)
Response.BinaryWrite rsBlob(0)
rsBlob.Close
Set rsBlob = Nothing
Response.End
%>
The the following is displayed in the browser
after the asp is executed...
<font face="Arial" size=2>
<p>Provider</font> <font face="Arial" size=2>error '80004005'</font>
<p>
<font face="Arial" size=2>Unspecified error</font>
<p>
<font face="Arial" size=2>/ASPSamp/oracbir/sujal/imgtrialora.asp</font><font face="Arial" size=2>, line 38</font>
NB:- Line 38 is where the query is executed. i.e set rsBlob = cn.Execute(SQLQuery)
Could you tell me what I did wrong? I am using Oracle 8.1.6 on Win NT..
Does field of type ORDSYS.ORDVIR have extra info stored along with the image which needs to be removed before displaying the image..
null

Answer 1

Since ODBC does not understand Oracle object types, you must select the BLOB locater, not the VIR Object.
One you've done that you need to loop over the data in the BLOB, pushing it out the Binary response object.
You may also want to select the mimetype from the VIR object and use that value to set the content type of the response object.
Here's a piece of code that does the job:
strSQL = "SELECT t.IMAGE_THUMB.getMimetype(), t.IMAGE_THUMB.getContentLength(), t.IMAGE_THUMB.getContent() FROM IMPB.IMAGE_ITEMS t WHERE IMAGE_ID = 1"
set rsOrdMediaSource = Server.CreateObject("ADODB.Recordset")
rsOrdMediaSource.ActiveConnection = "dsn=impb_imperf;uid=impb;pwd=impb;"
rsOrdMediaSource.Source = strSQL
rsOrdMediaSource.CursorType = 0
rsOrdMediaSource.CursorLocation = 2
rsOrdMediaSource.LockType = 1
rsOrdMediaSource.MaxRecords = 1
rsOrdMediaSource.Open()
If rsOrdMediaSource.EOF Then
Response.Status = "404 Not Found"
Response.End
End If
Dim blob
Dim bytesToGo
bytesToGo = rsOrdMediaSource.Fields.Item(1).value
Dim vBuffer
set blob = rsOrdMediaSource.Fields.Item(2)
If Response.Buffer Then Response.Clear
Response.Buffer = false
Response.ContentType=rsOrdMediaSource.Fields.Item(0).value
While bytesToGo > 0
vBuffer = blob.getChunk(CLng(32768))
Response.BinaryWrite(vBuffer)
bytesToGo = bytesToGo - 32768
Wend
Reponse.End
null