# `Tempo.Ecto.SQLite.TempoRange`
[🔗](https://github.com/elixir-tempo/tempo_sql/blob/v0.4.0/lib/tempo/ecto/sqlite/tempo_range.ex#L2)

Ecto.ParameterizedType that stores a Tempo expression whole in a
SQLite `TEXT` column.

SQLite has no range type. The column holds the JSON document
`Tempo.SQL.SQLite.Document` writes: the expression's ISO 8601 text,
read back as it was written, beside the integer bounds of the time it
covers and of each of its spans, which `Tempo.Ecto.SQLite.QueryAPI`
queries. It takes any expression with ISO 8601 text and a place on
the time line: a value, an interval, a set, a recurrence.

## Usage

    schema "meetings" do
      field :window, Tempo.Ecto.SQLite.TempoRange
      field :opening_hours, Tempo.Ecto.SQLite.TempoRange, frame: :floating
    end

and in the migration:

    import Tempo.SQL.SQLite.Migration

    create table(:meetings) do
      add_tempo_range :window
    end

    create_tempo_range_index :meetings, :window

## Options

  * `:frame` — `:utc` (the default) for values in a zone or at a
    time shift, stored as seconds since the Unix epoch at UTC, or
    `:floating` for values with neither, stored as seconds on the
    wall clock. A value of the other frame is refused by `cast/2`,
    as a changeset error that names the frame to declare, and by
    `dump/3`.

## Precision

The bounds are whole seconds, rounded outward, so a query of a span
shorter than a second may find its neighbours. The expression itself
is kept as written and loads back exactly.

# `cast_type`

```elixir
@spec cast_type(keyword()) :: Ecto.Type.t()
```

Builds the parameterized-type tuple for use outside a schema.

### Arguments

* `options` is a keyword list of options.

### Options

* `:frame` is `:utc` (the default) or `:floating`.

### Returns

* A `t:Ecto.ParameterizedType.opts/0` tuple.

### Examples

    iex> Tempo.Ecto.SQLite.TempoRange.cast_type()
    {:parameterized, {Tempo.Ecto.SQLite.TempoRange, %{frame: :utc}}}

    iex> Tempo.Ecto.SQLite.TempoRange.cast_type(frame: :floating)
    {:parameterized, {Tempo.Ecto.SQLite.TempoRange, %{frame: :floating}}}

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