> ## Documentation Index
> Fetch the complete documentation index at: https://docs.paradedb.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Histogram

> Count the number of occurrences over some interval

The histogram aggregation dynamically creates buckets for a given `interval` and counts the number of occurrences
in each bucket.

Each value is rounded down to its bucket. For instance, a rating of `18` with an interval of `5` rounds down to a bucket
with key `15`.

<CodeGroup>
  ```sql SQL theme={null}
  SELECT pdb.agg('{"histogram": {"field": "rating", "interval": "1"}}')
  FROM mock_items
  WHERE id @@@ pdb.all();
  ```

  ```ts Drizzle theme={null}
  import { search } from "@paradedb/drizzle-paradedb";

  await db
    .select({
      agg: search.agg({ histogram: { field: "rating", interval: "1" } }),
    })
    .from(mockItems)
    .where(search.all(mockItems.id));
  ```

  ```python Django theme={null}
  from paradedb import Agg, All, ParadeDB

  MockItem.objects.filter(
      id=ParadeDB(All())
  ).aggregate(agg=Agg('{"histogram": {"field": "rating", "interval": "1"}}'))
  ```

  ```python SQLAlchemy theme={null}
  from sqlalchemy import select
  from sqlalchemy.orm import Session
  from paradedb.sqlalchemy import facets, pdb, search

  stmt = (
      select(pdb.agg(facets.histogram(field="rating", interval=1)))
      .select_from(MockItem)
      .where(search.all(MockItem.id))
  )

  with Session(engine) as session:
      session.execute(stmt).all()
  ```

  ```ruby Rails theme={null}
  MockItem.search(:id)
          .match_all
          .facets_agg(agg: ParadeDB::Aggregations.histogram(:rating, interval: 1))
  ```

  ```cs EF Core theme={null}
  await dbContext
      .MockItems.Where(item => EF.Functions.All(item.Id))
      .Select(item => EF.Functions.Agg(new { histogram = new { field = "rating", interval = "1" } }))
      .ToListAsync();
  ```
</CodeGroup>

```ini Expected Response theme={null}
                                                                                  agg
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------
 {"buckets": [{"key": 1.0, "doc_count": 1}, {"key": 2.0, "doc_count": 3}, {"key": 3.0, "doc_count": 9}, {"key": 4.0, "doc_count": 16}, {"key": 5.0, "doc_count": 12}]}
(1 row)
```

See the [Tantivy documentation](https://docs.rs/tantivy/latest/tantivy/aggregation/bucket/struct.HistogramAggregation.html)
for all available options.