Python flask.g 模块，sqlite_db() 实例源码

def get_db():
    """Opens a new database connection if there is none yet for the
    current application context.
    """
    if not hasattr(g, 'sqlite_db'):
        g.sqlite_db = connect_db()
    return g.sqlite_db

def close_db(error):
    """Closes the database again at the end of the request."""
    if hasattr(g, 'sqlite_db'):
        g.sqlite_db.close()

def get_db():
    """
    Opens a new database connection if there is none yet for the
    current application context.
    """
    if not hasattr(g, 'sqlite_db'):
        g.sqlite_db = connect_db()
    return g.sqlite_db

def get_db():
    '''Opens a new database connection if there is none yet for the
    current application context.'''
    if not hasattr(g, 'sqlite_db'):
        g.sqlite_db = connect_db()
        debug('Database connection created.')
    return g.sqlite_db

def close_db(error):
    '''Closes the database again at the end of the request.'''
    if hasattr(g, 'sqlite_db'):
        g.sqlite_db.close()
        debug('Database connection destroyed.')

def get_db():
    # g is a general purpose variable associated with the current application context
    if not hasattr(g, 'sqlite_db'):
        g.sqlite_db = connect_db()
    return g.sqlite_db

# initialise the db

def close_db(error):
    """Closes the database again at the end of the request."""
    if hasattr(g, 'sqlite_db'):
        g.sqlite_db.close()

def db_open():
    """Opens a new database connection if there is none yet for the
    current application context.
    """
    if not hasattr(g, 'sqlite_db'):
        g.sqlite_db = db_connect()
    return g.sqlite_db

def close_db(error):
    """Closes the database again at the end of the request."""
    if hasattr(g, 'sqlite_db'):
        g.sqlite_db.close()

################################################################################
# Intersections
################################################################################

def get_db():
    if not hasattr(g, 'sqlite_db'):
        g.sqlite_db = connect_db()
    return g.sqlite_db

def close_db(error):
    if hasattr(g, 'sqlite_db'):
        g.sqlite_db.close()