db module

For all database connection needs.

This module provides DatabaseConnection:

The base connection class with three methods: DatabaseConnection.connect(), DatabaseConnection.close() and DatabaseConnection.is_connected().

class db.DatabaseConnection(logger_name: str)

Bases: object

The base class to represent a connection to a PostgreSQL database.

Parameters

logger_name (str) – The name of the logger to be used by the connection.

async connect(host: str, user: str, password: str, database: str, loop: Optional[asyncio.events.AbstractEventLoop] = None, port: Optional[str] = None) → asyncpg.connection.Connection

Connect to a database using the credentials provided. Stores connection in self.conn.

Parameters

  • host (str) – The hostname, usually ‘localhost’.

  • user (str) – A user with access to the database.

  • password (str) – The user’s password.

  • database (str) – The name of the database to connect to.

  • loop (asyncio.AbstractEventLoop) – The asyncio loop to use. If None, asyncpg uses the default event loop. None by default.

  • port (str) – The port to use, usually 5432. None by default.

async close() → bool

Closes the connection to the database.

Returns

True if the connection was closed, False if there was no connection to close.

Return type

bool

async is_connected() → bool

Check if the connection is active.

Returns

True if there’s a connection, False otherwise.

Return type

bool

exception db.DbInsertError

Bases: Exception

Raised when an error related to INSERT occurs.

exception db.NotFoundError

Bases: Exception

Raised when an error related to a missing result occurs.