版本環境
- python 3.7
- DBUtils 1.3
- mysqlclient 1.4.6
連接池初始化
pool = PooledDB(creator=MySQLdb, mincached=0, maxcached=0,
maxshared=0, maxconnections=0, blocking=False,
maxusage=None, setsession=None, reset=True,
failures=None, ping=1,
*args, **kwargs)
參數說明
- creator
#creator => 任何符合DB-API 2.0規範的函數或者兼容的數據庫模塊
- mincached
#mincached => 初始化時,鏈接池中至少創建的空閒的鏈接,0表示不創建
- maxcached
#maxcached => 鏈接池中最大閒置的鏈接數(0和None不限制)
- maxshared
#maxshared => maximum number of shared connections (0 or None means all connections are dedicated) When this maximum number is reached, connections are shared if they have been requested as shareable
- maxconnections
#maxconnections => 允許的最大鏈接數(0或None表示不限制)
- blocking
#blocking => 鏈接池沒有可用鏈接後,是否阻塞等待。 True表示阻塞等待,直到獲取到鏈接; False不等待,拋異常退出
- maxusage
#maxusage => 同一個鏈接最多被重複使用的次數(0和None表示無限制)
- setsession
#setsession => 可選的會話命令:開始會話前執行的命令列表。 例如["set datestyle to…","set time zone…"]
- reset
#reset => 當連接放回池中時,重置連接的方式,默認爲True。 False或者None表示使用begin()開啓了事務的鏈接,會執行回滾; 安全起見,建議使用True,當爲True時表示所有鏈接都執行回滾操作
- failures
#failures => 當默認的(OperationalError,InternalError)異常不能滿足要求時, 可以自定義拋出異常:默認爲None; 自定義爲傳入的爲tuple或者issubclass(failures, Exception)
- ping
#ping => 檢查連接是否仍然處於活動狀態的方式 0 = None = never, 1 = default = whenever fetched from the pool, 2 = when a cursor is created, 4 = when a query is executed, 7 = always, and all other bit combinations of these values
- args, kwargs
#args, kwargs => 傳遞給creator的參數
使用
# -*- coding: utf-8 -*-
# @Time : 2020/1/26 0026 20:28
# @Email : [email protected](擼小魚)
import MySQLdb
import MySQLdb.cursors
from DBUtils.PooledDB import PooledDB
import datetime
class DbManager(object):
def __init__(self, host, port, db_name, user_name, password):
cmds = ["set names utf8mb4;"]
conn_args = {'host': host,
'port': port,
'db': db_name,
'user': user_name,
'passwd': password,
'charset': 'utf8',
'cursorclass': MySQLdb.cursors.DictCursor
}
# 初始化時,鏈接池中至少創建的空閒的鏈接,0表示不創建,mincached: 5
# 鏈接池中最大閒置的鏈接數(0和None不限制): 20
self._pool = PooledDB(MySQLdb, mincached=5, maxcached=20, setsession=cmds, **conn_args)
def connection(self):
return self._pool.connection()
_db_manager = None
def create_db_manager(host, port, dbname, username, password):
global _db_manager
if _db_manager is None:
_db_manager = DbManager(host, port, dbname, username, password)
return _db_manager