--- title: Count description: Count the number of values in a field canonical: https://docs.paradedb.com/documentation/aggregates/metrics/count --- The following query counts the number of values in a field: ```sql SQL SELECT pdb.agg('{"value_count": {"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('{"value_count": {"field": "rating"}}')) ``` ```python SQLAlchemy from sqlalchemy import select from sqlalchemy.orm import Session from paradedb.sqlalchemy import facets, pdb, search stmt = ( select(pdb.agg(facets.value_count(field="rating"))) .select_from(MockItem) .where(search.all(MockItem.id)) ) with Session(engine) as session: session.execute(stmt).all() ``` ```ruby Rails MockItem.search(:id) .match_all .facets_agg(agg: ParadeDB::Aggregations.value_count(:rating)) ``` ```ini Expected Response agg ----------------- {"value": 41.0} (1 row) ``` See the [Tantivy documentation](https://docs.rs/tantivy/latest/tantivy/aggregation/metric/struct.CountAggregation.html) for all available options. ## SQL Count Syntax SQL's `COUNT` 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 COUNT(rating) FROM mock_items WHERE id @@@ pdb.all(); ``` ```python Django from django.db.models import Count from paradedb import All, ParadeDB MockItem.objects.filter( id=ParadeDB(All()) ).aggregate(count=Count('rating')) ``` ```python SQLAlchemy from sqlalchemy import func, select from sqlalchemy.orm import Session from paradedb.sqlalchemy import search stmt = ( select(func.count(MockItem.rating)) .select_from(MockItem) .where(search.all(MockItem.id)) ) with Session(engine) as session: session.execute(stmt).all() ``` ```ruby Rails MockItem.search(:id).match_all.count(:rating) ``` To count all rows, including rows with null values, use `COUNT(*)`: ```sql SQL SELECT COUNT(*) FROM mock_items WHERE id @@@ pdb.all(); ``` ```python Django from paradedb import All, ParadeDB MockItem.objects.filter(id=ParadeDB(All())).count() ``` ```python SQLAlchemy from sqlalchemy import func, select from sqlalchemy.orm import Session from paradedb.sqlalchemy import search stmt = ( select(func.count()) .select_from(MockItem) .where(search.all(MockItem.id)) ) with Session(engine) as session: session.execute(stmt).all() ``` ```ruby Rails MockItem.search(:id).match_all.count ```