Doug, I have updated my test code in line with your excellent example and I now have the projection aspect working well.
Now... I'm stuck on a schema evolution test. Basically if I use your example as the foundation and I create a new schema based on the WRITER_SCHEMA in which I add a new field to the end (to model schema evolution) I receive an error when trying to create the writer_iface. writer_iface = avro_resolved_writer_new(writer_schema, reader_schema); "Reader field Field_3 doesn't appear in writer" Any chance you could extending your example to show the ability of Avro to read data from a data file using an evolved schema (say in a simple situation were a new field is added to the schema)? Regards, Chris On Fri, Mar 1, 2013 at 9:08 AM, Douglas Creager <[email protected]>wrote: > > Thanks for the informative reply. I look forward to the example code, > > that is exactly what I'm after. > > > > I'm really struggling with my schema evolution testing. I thought I'd > > post a question about schema projection because it seemed simpler but I > > guess it also rests on creating a resolver. I have not found a clear and > > simple example of how to do it using avro-c. I've trawled the test code > > for examples but as I mention I can't find a clear and simple example. > > Alrighty, here you go: > > http://dcreager.github.com/avro-examples/resolved-writer.html > > And a git repo with the source code: > > https://github.com/dcreager/avro-examples/tree/master/resolved-writer > > I hope this helps — please let me know if you have any other questions. > > cheers > –doug > >
