db.py 文件源码

def extract_dsn(dsn_dict: Dict[str, str], read_only=False):
    """
    Break the connection string into a JDBC URL and connection properties.

    This is necessary since a JDBC URL may not contain all the properties needed
    to successfully connect, e.g. username, password.  These properties must
    be passed in separately.

    Use the postgresql subprotocol and driver regardless of whether the connection
    string's protocol was postgres or redshift.
    """
    dsn_properties = dict(dsn_dict)  # so as to not mutate the argument
    dsn_properties.update({
        "ApplicationName": __name__,
        "readOnly": "true" if read_only else "false",
        "driver": "org.postgresql.Driver"
    })
    if "port" in dsn_properties:
        jdbc_url = "jdbc:postgresql://{host}:{port}/{database}".format(**dsn_properties)
    else:
        jdbc_url = "jdbc:postgresql://{host}/{database}".format(**dsn_properties)
    return jdbc_url, dsn_properties