Hi,

We create a table with multiple fields, and add bgUid field with default value: GENERATE_UUID(), when jsonWriter.appendRows, field bgUid is not included in json list. We assume one UUID should be generated as the default value, while the value we got is null.

After filter the field from TableMetadata, default values will take effect. This is not expected. It is expected that when one field is not defined, the default value will take effect. And that is also what the bigquery API do.

Code to filter field:

  const table = bigquery.dataset(datasetId).table(tableId);
  const [metadata] = (await table.getMetadata()) as [TableMetadata, unknown];
  const { schema } = metadata as { schema: Schema };
  schema.fields.filter(field=> field.name != 'bgUid');

Thanks,