@spec disconnect_all(
  pid() | Ecto.Repo.t() | Ecto.Adapter.adapter_meta(),
  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 connections will be randomly disconnected within the given time interval. Pinged connections are immediately disconnected - as they are idle (according to :idle_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.

For convenience, this function is also available in the repository:

iex> MyRepo.disconnect_all(60_000)
:ok

@spec explain(
  pid() | Ecto.Repo.t() | Ecto.Adapter.adapter_meta(),
  :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> Ecto.Adapters.SQL.explain(Repo, :all, Post)
"Seq Scan on posts p0  (cost=0.00..12.12 rows=1 width=443)"

# MySQL
iex> Ecto.Adapters.SQL.explain(Repo, :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> Ecto.Adapters.SQL.explain(Repo, :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> Ecto.Adapters.SQL.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> Repo.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:

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

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 compatiblity, please check your database's documentation:

• Postgrex: PostgreSQL doc.
• MyXQL: MySQL doc.

@spec query(
  pid() | Ecto.Repo.t() | Ecto.Adapter.adapter_meta(),
  iodata(),
  [term()],
  Keyword.t()
) ::
  {:ok, query_result()} | {:error, Exception.t()}

Runs a custom SQL query on the given repo.

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

For convenience, this function is also available under the repository:

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

@spec query!(
  pid() | Ecto.Repo.t() | Ecto.Adapter.adapter_meta(),
  iodata(),
  [term()],
  Keyword.t()
) ::
  query_result()

Same as query/4 but raises on invalid queries.

@spec query_many(
  pid() | Ecto.Repo.t() | Ecto.Adapter.adapter_meta(),
  iodata(),
  [term()],
  Keyword.t()
) :: {:ok, [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> Ecto.Adapters.SQL.query_many(MyRepo, "SELECT $1; SELECT $2;", [40, 2])
{:ok, [%{rows: [[40]], num_rows: 1}, %{rows: [[2]], num_rows: 1}]}

For convenience, this function is also available under the repository:

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

@spec query_many!(
  Ecto.Repo.t() | Ecto.Adapter.adapter_meta(),
  iodata(),
  [term()],
  Keyword.t()
) :: [
  query_result()
]

Same as query_many/4 but raises on invalid queries.

@spec stream(Ecto.Repo.t(), String.t(), [term()], Keyword.t()) :: Enum.t()

Returns a stream that runs a custom SQL query on given repo when reduced.

In case of success it is a enumerable containing 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)

In case of failure it raises an exception.

If the adapter supports a collectable stream, the stream may also be used as the collectable in Enum.into/3. Behaviour depends on the adapter.

Options

• :log - When false, does not log the query
• :max_rows - The number of rows to load from the database as we stream

Examples

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

@spec table_exists?(Ecto.Repo.t(), table :: String.t(), opts :: Keyword.t()) ::
  boolean()

Check if the given table exists.

Returns true if the table exists in the repo, otherwise false. The table is checked against the current database/schema in the connection.

@spec to_sql(:all | :update_all | :delete_all, Ecto.Repo.t(), Ecto.Queryable.t()) ::
  {String.t(), [term()]}

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

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

This function is also available under the repository with name to_sql:

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