How to add Default Category to the Product index

Some site implementations need to add the Product's default Category to the SOLR index.  The categories for products are managed in an associated table (blc_category_product_xref) and the default Category is marked as the "default_reference" in that xref table.  The ability to identify and index the default Category can be confusing.  Fortunately, we do have a helper method to allow us to get to the default Category.  The ProductImpl#getCategory() method is implemented to find the default Category.

The ability to find the default Category through the getCategory method makes the addition of the default Category into the SOLR index much easier.  Here are the steps needed:

1) Add the defaultCategory field to the blc_field table.  This is a manual entry into the database.

 (-1599, 'defCat', NULL, NULL, NULL, NULL, NULL, NULL, 'PRODUCT', 'Default Category', NULL, '', NULL);
2) Add the associated entries into the blc_index_field and blc_index_field_type tables.  These tables can typically be edited through the admin.  If you use the Multi-Tenant module, these entries would likely be added to the "global" template site.  Here are the SQL inserts should you want to update the database directly.
INSERT INTO `blc_index_field` (`INDEX_FIELD_ID`, `ARCHIVED`, `CATALOG_DISC`, `SEARCHABLE`, `FIELD_ID`) VALUES (-1599, 'N', -1, 1, -1599);
INSERT INTO `blc_index_field_type` (`INDEX_FIELD_TYPE_ID`, `ARCHIVED`, `CATALOG_DISC`, `FIELD_TYPE`, `INDEX_FIELD_ID`) VALUES (-1599, 'N', -1, 't', -1599);
3) Once the blc_field, blc_index_field, and blc_index_field_type entries are added to the database, the SOLR reindex will need to re-run.