Re: [eclipselink-users] Write BLOB using EntityManager

[James Sutherland <jamesssss@xxxxxxxxx>]

If you have an object mapped to the table, you could try just reading and
updating the entire blob as a byte[] in the object.  If you use the
Oracle9Platform we will stream the blob to get around the 4k size limit.

Otherwise to stream the blob yourself is pretty low-level JDBC, you may need
to continue using JDBC code for this.


Leon Derks-2 wrote:
> 
> Hello
> 
> I have a question, how can I write data to a blob, using the 
> EntityManager.createNativeQuery("select image_data from image_blobs 
> where image_id = ? and image_type = ? for update nowait")?
> How can I get the stream from the blob?
> 
> I used to do this as follows:
> PreparedStatement stmt = conn.prepareStatement("select image_data from 
> image_blobs where image_id = ? and image_type = ? for update nowait");
>         stmt.setLong(1, image.getId().longValue());
>         stmt.setString(2, image.getType());
>         res = (OracleResultSet) stmt.executeQuery();
> 
>         // get the stream from the blob and let data be streamed into it
>         if (res.next()) {
>           BLOB oracleBLOB = res.getBLOB(1);
>           OutputStream out = oracleBLOB.setBinaryStream(0L);
>           streamer.stream(out);
>           out.close();
> 
>           // now determin the size
>           res.close();
>           stmt.close();
>           stmt = conn.prepareStatement(GET_SIZE);
>           stmt.setLong(1, image.getId().longValue());
>           stmt.setString(2, sizeName);
>           res = (OracleResultSet) stmt.executeQuery();
>           if (res.next()) {
>             size = res.getLong(1);
>           }
>         }
> 
> Leon
> 


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