Module: DynamicMigrations::Postgres::Server::Database::Connection

Included in:
DynamicMigrations::Postgres::Server::Database
Defined in:
lib/dynamic_migrations/postgres/server/database/connection.rb

Defined Under Namespace

Classes: AlreadyConnectedError, MissingDatabaseNameError, NotConnectedError

Instance Method Summary collapse

Instance Method Details

#connect ⇒ Object

Raises:



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# File 'lib/dynamic_migrations/postgres/server/database/connection.rb', line 17

def connect
  raise MissingDatabaseNameError unless name
  raise AlreadyConnectedError if @connection
  @connection = Postgres::Connections.create_connection server.host, server.port, server.username, server.password, name
end

#connected? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dynamic_migrations/postgres/server/database/connection.rb', line 36

def connected?
  !@connection.nil?
end

#connection ⇒ Object 



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# File 'lib/dynamic_migrations/postgres/server/database/connection.rb', line 23

def connection
  @connection || raise(NotConnectedError)
end

#disconnect ⇒ Object 



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# File 'lib/dynamic_migrations/postgres/server/database/connection.rb', line 27

def disconnect
  if (conn = @connection)
    Postgres::Connections.disconnect conn
    @connection = nil
  else
    raise NotConnectedError
  end
end

#with_connection(&block) ⇒ Object

Opens a connection to the database server, and yields the provided block before automatically closing the connection again. This is useful for executing one time queries against the database server.



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# File 'lib/dynamic_migrations/postgres/server/database/connection.rb', line 43

def with_connection &block
  # create a temporary connection to the server (unless we are already connected)
  already_connected = connected?
  unless already_connected
    connect
  end

  # perform work with the connection
  # todo: `yield connection` would have been preferred, but rbs/steep doesnt understand that syntax
  if block.is_a? Proc
    result = block.call connection
  end

  # close the connection (unless we were already connected)
  if already_connected
    disconnect
  end

  # return whever was returned from within the block
  result
end