# `Nucleus.Repo`

# `aggregate`

# `aggregate`

# `all`

# `all_by`

# `checked_out?`

# `checkout`

# `child_spec`

# `config`

# `default_options`

# `delete`

# `delete!`

# `delete_all`

# `disconnect_all`

```elixir
@spec disconnect_all(non_neg_integer(), opts :: Keyword.t()) :: :ok
```

Forces all connections in the repo pool to disconnect within the given interval.

Once this function is called, the pool will disconnect all of its connections
as they are checked in or as they are pinged. Checked in and idle connections
will be randomly disconnected within the given time interval.

If the connection has a backoff configured (which is the case by default),
disconnecting means an attempt at a new connection will be done immediately
after, without starting a new process for each connection. However, if backoff
has been disabled, the connection process will terminate. In such cases,
disconnecting all connections may cause the pool supervisor to restart
depending on the max_restarts/max_seconds configuration of the pool,
so you will want to set those carefully.

If you need connections to be restarted periodically, set the `:max_lifetime`
option in your repository configuration instead.

# `exists?`

# `explain`

```elixir
@spec explain(
  :all | :update_all | :delete_all,
  Ecto.Queryable.t(),
  opts :: Keyword.t()
) ::
  String.t() | Exception.t() | [map()]
```

Executes an EXPLAIN statement or similar for the given query according to its kind and the
adapter in the given repository.

## Examples

    # Postgres
    iex> MyRepo.explain(:all, Post)
    "Seq Scan on posts p0  (cost=0.00..12.12 rows=1 width=443)"

    iex> Ecto.Adapters.SQL.explain(Repo, :all, Post)
    "Seq Scan on posts p0  (cost=0.00..12.12 rows=1 width=443)"

    # MySQL
    iex> MyRepo.explain(:all, from(p in Post, where: p.title == "title")) |> IO.puts()
    +----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+-------------+
    | id | select_type | table | partitions | type | possible_keys | key  | key_len | ref  | rows | filtered | Extra       |
    +----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+-------------+
    |  1 | SIMPLE      | p0    | NULL       | ALL  | NULL          | NULL | NULL    | NULL |    1 |    100.0 | Using where |
    +----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+-------------+

    # Shared opts
    iex> MyRepo.explain(:all, Post, analyze: true, timeout: 20_000)
    "Seq Scan on posts p0  (cost=0.00..11.70 rows=170 width=443) (actual time=0.013..0.013 rows=0 loops=1)\nPlanning Time: 0.031 ms\nExecution Time: 0.021 ms"

It's safe to execute it for updates and deletes, no data change will be committed:

    iex> MyRepo.explain(Repo, :update_all, from(p in Post, update: [set: [title: "new title"]]))
    "Update on posts p0  (cost=0.00..11.70 rows=170 width=449)\n  ->  Seq Scan on posts p0  (cost=0.00..11.70 rows=170 width=449)"

This function is also available under the repository with name `explain`:

    iex> MyRepo.explain(:all, from(p in Post, where: p.title == "title"))
    "Seq Scan on posts p0  (cost=0.00..12.12 rows=1 width=443)\n  Filter: ((title)::text = 'title'::text)"

### Options

Built-in adapters support passing `opts` to the EXPLAIN statement according to the following:

Adapter          | Supported opts
---------------- | --------------
Postgrex         | `analyze`, `verbose`, `costs`, `settings`, `buffers`, `timing`, `summary`, `format`, `plan`, `wrap_in_transaction`
MyXQL            | `format`, `wrap_in_transaction`

All options except `format` are boolean valued and default to `false`.

The allowed `format` values are `:map`, `:yaml`, and `:text`:
  * `:map` is the deserialized JSON encoding.
  * `:yaml` and `:text` return the result as a string.

The built-in adapters support the following formats:
  * Postgrex: `:map`, `:yaml` and `:text`
  * MyXQL: `:map` and `:text`

The `wrap_in_transaction` option is a boolean that controls whether the command is run inside of a
transaction that is rolled back. This is useful when, for example, you'd like to use `analyze: true`
on an update or delete query without modifying data. Defaults to `true`.

The `:plan` option in Postgrex can take the values `:custom` or `:fallback_generic`. When `:custom`
is specified, the explain plan generated will consider the specific values of the query parameters
that are supplied. When using `:fallback_generic`, the specific values of the query parameters will
be ignored. `:fallback_generic` does not use PostgreSQL's built-in support for a generic explain
plan (available as of PostgreSQL 16), but instead uses a special implementation that works for PostgreSQL
versions 12 and above. Defaults to `:custom`.

Any other value passed to `opts` will be forwarded to the underlying adapter query function, including
shared Repo options such as `:timeout`. Non built-in adapters may have specific behaviour and you should
consult their documentation for more details.

For version compatibility, please check your database's documentation:

  * _Postgrex_: [PostgreSQL doc](https://www.postgresql.org/docs/current/sql-explain.html).
  * _MyXQL_: [MySQL doc](https://dev.mysql.com/doc/refman/8.0/en/explain.html).

# `get`

# `get!`

# `get_by`

# `get_by!`

# `get_dynamic_repo`

# `in_transaction?`

# `insert`

# `insert!`

# `insert_all`

# `insert_or_update`

# `insert_or_update!`

# `load`

# `one`

# `one!`

# `preload`

# `prepare_query`

# `prepare_transaction`

# `put_dynamic_repo`

# `query`

```elixir
@spec query(iodata(), Ecto.Adapters.SQL.query_params(), Keyword.t()) ::
  {:ok, Ecto.Adapters.SQL.query_result()} | {:error, Exception.t()}
```

Runs a custom SQL query.

If the query was successful, it will return an `:ok` tuple containing
a map with at least two keys:

  * `:num_rows` - the number of rows affected
  * `:rows` - the result set as a list. `nil` may be returned
    instead of the list if the command does not yield any row
    as result (but still yields the number of affected rows,
    like a `delete` command without returning would)

## Options

  * `:log` - When false, does not log the query
  * `:timeout` - Execute request timeout, accepts: `:infinity` (default: `15000`);

## Examples

    iex> MyRepo.query("SELECT $1::integer + $2", [40, 2])
    {:ok, %{rows: [[42]], num_rows: 1}}

    iex> Ecto.Adapters.SQL.query(MyRepo, "SELECT $1::integer + $2", [40, 2])
    {:ok, %{rows: [[42]], num_rows: 1}}

# `query!`

```elixir
@spec query!(iodata(), Ecto.Adapters.SQL.query_params(), Keyword.t()) ::
  Ecto.Adapters.SQL.query_result()
```

Same as `query/3` but returns result directly without `:ok` tuple
and raises on invalid queries

# `query_many`

```elixir
@spec query_many(iodata(), Ecto.Adapters.SQL.query_params(), Keyword.t()) ::
  {:ok, [Ecto.Adapters.SQL.query_result()]} | {:error, Exception.t()}
```

Runs a custom SQL query that returns multiple results on the given repo.

In case of success, it must return an `:ok` tuple containing a list of
maps with at least two keys:

  * `:num_rows` - the number of rows affected

  * `:rows` - the result set as a list. `nil` may be returned
    instead of the list if the command does not yield any row
    as result (but still yields the number of affected rows,
    like a `delete` command without returning would)

## Options

  * `:log` - When false, does not log the query
  * `:timeout` - Execute request timeout, accepts: `:infinity` (default: `15000`);

## Examples

    iex> MyRepo.query_many("SELECT $1; SELECT $2;", [40, 2])
    {:ok, [%{rows: [[40]], num_rows: 1}, %{rows: [[2]], num_rows: 1}]}

    iex> Ecto.Adapters.SQL.query_many(MyRepo, "SELECT $1; SELECT $2;", [40, 2])
    {:ok, [%{rows: [[40]], num_rows: 1}, %{rows: [[2]], num_rows: 1}]}

# `query_many!`

```elixir
@spec query_many!(iodata(), Ecto.Adapters.SQL.query_params(), Keyword.t()) :: [
  Ecto.Adapters.SQL.query_result()
]
```

Same as `query_many/4` but returns result directly without `:ok` tuple
and raises on invalid queries

# `reload`

# `reload!`

# `rollback`

```elixir
@spec rollback(term()) :: no_return()
```

# `start_link`

# `stop`

# `stream`

# `to_sql`

```elixir
@spec to_sql(:all | :update_all | :delete_all, Ecto.Queryable.t(), Keyword.t()) ::
  {String.t(), Ecto.Adapters.SQL.query_params()}
```

Converts the given query to SQL according to its kind and the
adapter in the given repository.

## Examples

The examples below are meant for reference. Each adapter will
return a different result:

    iex> MyRepo.to_sql(:all, Post)
    {"SELECT p.id, p.title, p.inserted_at, p.created_at FROM posts as p", []}

    iex> MyRepo.to_sql(:update_all, from(p in Post, update: [set: [title: ^"hello"]]))
    {"UPDATE posts AS p SET title = $1", ["hello"]}

    iex> Ecto.Adapters.SQL.to_sql(:all, MyRepo, Post)
    {"SELECT p.id, p.title, p.inserted_at, p.created_at FROM posts as p", []}

# `transact`

# `transaction`

# `update`

# `update!`

# `update_all`

---

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