3 Replies Latest reply: Jan 9, 2012 4:17 PM by 643298 RSS

    passing blobs to stored procedure

    user11980810
      Hi,

      I'm looking for a way to pass blobs of different sizes (few kB up to some mB) from python to an oracle procedure within a package. I've tried cursor.callproc but it refuses to work for blobs.
      Perhaps there is somebody around somewhere who has done this already?

      Thanks for your help, Hannes
        • 1. Re: passing blobs to stored procedure
          390020
          Can you please share a little example of what you are doing? I have trouble picturing a blob (I mean I could open a pdf file, read some bytes and try to upload that to the db)but nevertheless if you can share a little snippet it will help with a faster answer.
          • 2. Re: passing blobs to stored procedure
            user11980810
            Hi Mariano.

            I already have a stored procedure in Oracle which gets a blob, is doing something with blob afterward and returns another blob. My python application is reading a file in, calls the oracle procedure (passes on the file to it), receives a blob and writes it to the file system. Reading and writing files from python is not the problem. Problem is how do I transfer it to or from the stored oracle procedure.

            Example:
            In Oracle
            create or replace package my_blob_proc (blob_in in blob, blob_out out blob)
            as
            begin
            < do something with blob_in>
            < put something on blob_out>
            end my_blob_proc;

            In Python:
            import cx_Oracle
            connection = cx_Oracle.connect('...')
            cursor = connection.cursor()
            f_blob = open('anyfile','rb')
            blob = f_blob.read()
            cursor.setinputsizes(blob=cx_Oracle.BLOB)
            # question is how do I call callproc to have a blob as input and another blob
            as output
            cursor.callproc('my_blob_proc', what do I have to put here to pass the blobs?)
            and continue writing blob_out to file ...

            Thanks a lot, Hannes
            • 3. Re: passing blobs to stored procedure
              643298
              You can try with cx_oracle.Connection.cursor.var(cx_Oracle.CLOB) as described here
              http://www.oracle.com/technetwork/articles/dsl/prez-transactions-lobs-089563.html