# `Postgrex.Query`
[🔗](https://github.com/elixir-ecto/postgrex/blob/v0.22.1/lib/postgrex/query.ex#L1)

Query struct returned from a successfully prepared query.

Its public fields are:

  * `name` - The name of the prepared statement;
  * `statement` - The prepared statement;
  * `columns` - The column names;
  * `ref` - A reference used to identify prepared queries;

## Prepared queries

Once a query is prepared with `Postgrex.prepare/4`, the
returned query will have its `ref` field set to a reference.
When `Postgrex.execute/4` is called with the prepared query,
it always returns a query. If the `ref` field in the query
given to `execute` and the one returned are the same, it
means the cached prepared query was used. If the `ref` field
is not the same, it means the query had to be re-prepared.

# `t`

```elixir
@type t() :: %Postgrex.Query{
  cache: :reference | :statement,
  columns: [String.t()] | nil,
  name: iodata(),
  param_formats: [:binary | :text] | nil,
  param_oids: [Postgrex.Types.oid()] | nil,
  param_types: [Postgrex.Types.type()] | nil,
  ref: reference() | nil,
  result_formats: [:binary | :text] | nil,
  result_oids: [Postgrex.Types.oid()] | nil,
  result_types: [Postgrex.Types.type()] | nil,
  statement: iodata(),
  types: Postgrex.Types.state() | nil
}
```

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