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ASF GitHub Bot commented on BEAM-2595: -------------------------------------- Github user asfgit closed the pull request at: https://github.com/apache/beam/pull/3563 > WriteToBigQuery does not work with nested json schema > ----------------------------------------------------- > > Key: BEAM-2595 > URL: https://issues.apache.org/jira/browse/BEAM-2595 > Project: Beam > Issue Type: Bug > Components: sdk-py > Affects Versions: 2.1.0 > Environment: mac os local runner, Python > Reporter: Andrea Pierleoni > Assignee: Sourabh Bajaj > Priority: Minor > Labels: gcp > Fix For: 2.1.0 > > > I am trying to use the new `WriteToBigQuery` PTransform added to > `apache_beam.io.gcp.bigquery` in version 2.1.0-RC1 > I need to write to a bigquery table with nested fields. > The only way to specify nested schemas in bigquery is with teh json schema. > None of the classes in `apache_beam.io.gcp.bigquery` are able to parse the > json schema, but they accept a schema as an instance of the class > `apache_beam.io.gcp.internal.clients.bigquery.TableFieldSchema` > I am composing the `TableFieldSchema` as suggested here > [https://stackoverflow.com/questions/36127537/json-table-schema-to-bigquery-tableschema-for-bigquerysink/45039436#45039436], > and it looks fine when passed to the PTransform `WriteToBigQuery`. > The problem is that the base class `PTransformWithSideInputs` try to pickle > and unpickle the function > [https://github.com/apache/beam/blob/master/sdks/python/apache_beam/transforms/ptransform.py#L515] > (that includes the TableFieldSchema instance) and for some reason when the > class is unpickled some `FieldList` instance are converted to simple lists, > and the pickling validation fails. > Would it be possible to extend the test coverage to nested json objects for > bigquery? > They are also relatively easy to parse into a TableFieldSchema. -- This message was sent by Atlassian JIRA (v6.4.14#64029)