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@127.0.0.1:5432/db")
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.127.0.0.1- 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.
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())