Connecting to your Database

When writing a application that uses a database, the first thing you need to do is to connect to the database. This is achieved through the usage of the DatabaseInterface provided by the library, using a Data Source Name.

db = DatabaseInterface("postgresql://myuser:mypassword@")

You can omit the DSN if you plan on providing it later.


Each part of the DSN represents something:

  • postgresql - The dialect this database is connecting to.
  • +asyncpg (implicit, not shown) - The driver used to connect.
  • myuser - The username to connect to the database through.
  • mypassword - The password for the user. This can be omitted if the user does not have a password.
  • - The hostname or IP being connected to.
  • 5432 - The port being connected to. If omitted, this will use the default port.
  • db - The database name to load.

Opening the Connection

Creating a database object does not actually connect to the database; for that you must use DatabaseInterface.connect() to open a new connection or connection pool for usage in the database.

# if you specified the DSN earlier
await db.connect()
# otherwise
await db.connect(dsn)

Once connected, you can do a test query to verify everything works:

async with db.get_transaction() as t:
    print(await (await t.cursor("SELECT 1;")).fetch_row())