--- title: Average description: Compute the average value of a field canonical: https://docs.paradedb.com/documentation/aggregates/metrics/average --- The following query computes the average value over a specific field: ```sql SQL SELECT pdb.agg('{"avg": {"field": "rating"}}') FROM mock_items WHERE id @@@ pdb.all(); ``` ```python Django from paradedb import Agg, All, ParadeDB MockItem.objects.filter( id=ParadeDB(All()) ).aggregate(agg=Agg('{"avg": {"field": "rating"}}')) ``` ```ruby Rails MockItem.search(:id) .match_all .facets_agg(agg: ParadeDB::Aggregations.avg(:rating)) ``` ```ini Expected Response agg ------------------------------- {"value": 3.8536585365853657} (1 row) ``` See the [Tantivy documentation](https://docs.rs/tantivy/latest/tantivy/aggregation/metric/struct.AverageAggregation.html) for all available options. ## SQL Average Syntax SQL's `AVERAGE` syntax is supported in beta. To enable it, first run ```sql SET paradedb.enable_aggregate_custom_scan TO on; ``` With this feature enabled, the following query is equivalent to the above and is executed in the same way. ```sql SQL SELECT AVG(rating) FROM mock_items WHERE id @@@ pdb.all(); ``` ```python Django from django.db.models import Avg from paradedb import All, ParadeDB MockItem.objects.filter( id=ParadeDB(All()) ).aggregate(avg_rating=Avg('rating')) ``` ```ruby Rails MockItem.search(:id).match_all.average(:rating) ``` By default, `AVG` ignores null values. Use `COALESCE` to include them in the final average: ```sql SQL SELECT AVG(COALESCE(rating, 0)) FROM mock_items WHERE id @@@ pdb.all(); ``` ```python Django from django.db.models import Avg, Value from django.db.models.functions import Coalesce from paradedb import All, ParadeDB MockItem.objects.filter( id=ParadeDB(All()) ).aggregate(avg_rating=Avg(Coalesce('rating', Value(0)))) ``` ```ruby Rails rating = MockItem.arel_table[:rating] coalesced_rating = Arel::Nodes::NamedFunction.new("COALESCE", [rating, Arel::Nodes.build_quoted(0)]) MockItem.search(:id).match_all.average(coalesced_rating) ```