# `Fude.Query`
[🔗](https://github.com/hattoriai/fude/blob/v0.1.0/lib/fude/query.ex#L2)

A chart's data from an Ecto query, grouped and aggregated in the
database: a chart of fifty million rows reads a few hundred.

    Fude.bar(Fude.query(Order, Repo), x: :status, y: {:count, :id})

    from(o in Order, where: o.shop_id == ^shop.id)
    |> Fude.query(Repo)
    |> Fude.line(x: {:month, :inserted_at}, y: {:sum, :total}, color: :channel)

For each layer, one `GROUP BY` query reads the channels that are not
aggregated (a field, its unit of time, its bin) and the aggregates of
the others (`count`, `sum`, `mean`, `min`, `max`, `distinct`). A
histogram reads the least and the greatest value first, for its bins.
PostgreSQL, MySQL and SQLite run them, each with its own functions of
dates.

A layer with no aggregate (a scatter of points), a `median`, or small
multiples read the rows' fields instead, only those the chart draws,
at most `:limit` rows.

The query may have its own `where`, `join` and `order_by`; the order
is dropped for the groups. Masu's grids give their filtered rows as a
query (`Masu.Live.selected/1`): a chart of what a grid shows.

## Options

  * `:repo_opts` - options for each call to the repo, such as `prefix:`.
  * `:limit` - the most rows read when they are read as they are;
    100,000 when not given.

# `t`

```elixir
@type t() :: %Fude.Query{
  limit: pos_integer(),
  query: Ecto.Query.t(),
  repo: module(),
  repo_opts: keyword()
}
```

# `new`

```elixir
@spec new(Ecto.Queryable.t(), module(), keyword()) :: t()
```

The data of an Ecto query or schema, read by `repo`.

---

*Consult [api-reference.md](api-reference.md) for complete listing*