def close_instance(self, connection: PooledMySQLConnection,
cursor: MySQLCursor) -> None:
if connection is not None and connection.is_connected():
if cursor is not None:
cursor.close()
connection.close()
self._logger.info(
f"MySQL connection is closed. - PID: {os.getpid()}")
else:
self._logger.info(
"Connection has been disconnect or be killed before.")
def get_connection(self):
"""Get a connection from the pool
This method returns an PooledMySQLConnection instance which
has a reference to the pool that created it, and the next available
MySQL connection.
When the MySQL connection is not connect, a reconnect is attempted.
Raises PoolError on errors.
Returns a PooledMySQLConnection instance.
"""
with CONNECTION_POOL_LOCK:
try:
cnx = self._cnx_queue.get(block=False)
except queue.Empty:
raise errors.PoolError(
"Failed getting connection; pool exhausted")
# pylint: disable=W0201,W0212
if not (yield from cnx.is_connected()) \
or self._config_version != cnx._pool_config_version:
cnx.config(**self._cnx_config)
try:
yield from cnx.reconnect()
except errors.InterfaceError:
# Failed to reconnect, give connection back to pool
self._queue_connection(cnx)
raise
cnx._pool_config_version = self._config_version
else:
print("get a pooled connector. current pool size is:", self._cnx_queue.qsize() )
return PooledMySQLConnection(self, cnx)
def _get_new_connection(self):
"""
Creates a new pooled mysql connection and adds it to the existing connection pool.
:return: a pooled mysql connection
"""
connection = self.create_connection()
pooled_connection = PooledMySQLConnection(self.connection_pool,
connection)
return pooled_connection
def show_tables(self, cnx: PooledMySQLConnection = None) -> list:
"""
数据库小助手-获取库中的表\n
:param cnx: 数据库连接，装饰器自动赋值
:return: 将数据库中表名列表予以返回
"""
cursor = cnx.cursor()
cursor.execute("SHOW TABLES")
tables = [row[0] for row in cursor.fetchall()]
return tables
def get_table_fields(self,
cnx: PooledMySQLConnection = None,
table: str = None):
"""
数据库小助手-获取表结构\n
:param cnx: 数据库连接，装饰器自动赋值
:param table: 表名
:return: 将表结构的字典列表予以返回（key:字段名，type:字段类型，null:是否为空）
"""
cursor = cnx.cursor()
cursor.execute(f"DESC {table}")
feilds = [{
'key': f[0],
'type': f[1],
'null': 'NULL' if f[2] == 'YES' else 'NOT NULL'
} for f in cursor.fetchall()]
return feilds
def build_cursor(self, connection: PooledMySQLConnection) -> MySQLCursor:
return connection.cursor()
def _close_connection(self, conn: PooledMySQLConnection) -> None:
if conn is not None:
conn.close()
def _commit(self, conn: PooledMySQLConnection) -> None:
conn.commit()
def _is_connected(self, conn: PooledMySQLConnection) -> bool:
return conn.is_connected()
def get_conn(self):
return PooledMySQLConnection(self, self._pool.get_connection())
def _commit(self,
connection: PooledMySQLConnection) -> PooledMySQLConnection:
connection.commit()
return connection
def _get_cursor(self, connetion: PooledMySQLConnection) -> MySQLCursor:
return connetion.cursor()
def _give_connection(self, connection: PooledMySQLConnection) -> None:
connection.close()
