Ecto.Adapters.SQL

Starts a transaction for test.

This function work by starting a transaction and storing the connection back in the pool with an open transaction. At the end of the test, the transaction must be rolled back with rollback_test_transaction, reverting all data added during tests.

IMPORTANT: Test transactions only work if the connection pool has size of 1 and does not support any overflow.

Example

The first step is to configure your database pool to have size of 1 and no max overflow. You set those options in your config/config.exs:

config :my_app, Repo,
  size: 1,
  max_overflow: 0

Since you don't want those options in your production database, we typically recommend to create a config/test.exs and add the following to the bottom of your config/config.exs file:

import_config "config/#{Mix.env}.exs"

Now with the test database properly configured, you can write transactional tests:

# All tests in this module will be wrapped in transactions
defmodule PostTest do
  # Tests that use the shared repository cannot be async
  use ExUnit.Case

  setup do
    Ecto.Adapters.SQL.begin_test_transaction(TestRepo)

    on_exit fn ->
      Ecto.Adapters.SQL.rollback_test_transaction(TestRepo)
    end
  end

  test "create comment" do
    assert %Post{} = TestRepo.insert(%Post{})
  end
end

Runs custom SQL query on 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

• :timeout - The time in milliseconds to wait for the call to finish, :infinity will wait indefinitely (default: 5000)

• :log - When false, does not log the query

Examples

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

Ends a test transaction, see begin_test_transaction/2.