How to specify a specific HAYStack_CONN?

'default': {
        'ENGINE': 'haystack.backends.elasticsearch5_backend.Elasticsearch5SearchEngine',
        'URL': 'http://127.0.0.1:9200/',
        'INDEX_NAME': 'article',
    },

    'example': {
        'ENGINE': 'haystack.backends.elasticsearch5_backend.Elasticsearch5SearchEngine',
        'URL': 'http://127.0.0.1:9200/',
        'INDEX_NAME': 'videoad',
   }

drf-haystack query result always use default connection, The question is how to use example for query?

This haystack doc could use connection you want.

from haystack.query import SearchQuerySet

# Uses the routers' opinion.
sqs = SearchQuerySet().auto_query('banana')

# Forces the default.
sqs = SearchQuerySet().using('default').auto_query('banana')

# Forces the slave connection (presuming it was setup).
sqs = SearchQuerySet().using('slave').auto_query('banana')

But I use drf-haystack.

Configuring Haystack Connection in Django

Suppose you have a Haystack connection configured in your settings.py file like this:

HAYSTACK_CONNECTIONS = {
    # Default connection settings go here ...

    'example': {
        'ENGINE': "haystack.backends.solr_backend.SolrEngine",
        'URL': "http://127.0.0.1:8983/solr/example",
        'ADMIN_URL': "http://127.0.0.1:8983/solr/admin/cores"
    }
}

In this example, we’ve defined a custom Haystack connection called example, which is configured to use the Solr engine.

Using a Specific Haystack Connection with `drf-haystack`

To use this specific connection (like example) with drf-haystack in your views, you can set it directly within the get_queryset method of your view class. By appending .using('example') to the SearchQuerySet, you ensure that the correct Haystack connection is used for your search queries.

Here’s how you can implement this in your view:

class BillViewSet(HaystackViewSet):
    index_models = [Bill]  # This will include only Bill Django model results in the SearchQuerySet()
    serializer_class = BillSerializer

    def get_queryset(self, index_models=[]):
        # Ensure the query uses the 'example' Haystack connection
        sqs = super(BillViewSet, self).get_queryset(index_models).using("example")
        return sqs

Inspecting the Search QuerySet

Once you have set up the connection, you can inspect the SearchQuerySet to confirm that it is correctly targeting the example connection. You can do this by printing the sqs object in a debugger like pdb:

(Pdb) print(sqs)
<SearchQuerySet: query=<haystack.backends.solr_backend.SolrSearchQuery object at 0x74f8bae8dc40>, using='example'>

(Pdb) print(sqs._using)
example

Here, sqs._using should print example, indicating that the query is indeed using the correct connection.

Summary

The HAYSTACK_CONNECTIONS setting allows you to define multiple search connections.
Use .using('example') in your get_queryset method to specify which connection to use when querying.
You can verify the connection by inspecting the SearchQuerySet object.

This approach ensures that your view queries the correct Haystack connection, making it easier to work with multiple search engines or configurations in a single project.

rhblind / drf-haystack