数据库连接池
一、配置
1.1 setting.py
from datetime import timedelta from redis import Redis import pymysql from DBUtils.PooledDB import PooledDB, SharedDBConnection class Config(object): DEBUG = True SECRET_KEY = "umsuldfsdflskjdf" PERMANENT_SESSION_LIFETIME = timedelta(minutes=20) SESSION_REFRESH_EACH_REQUEST= True SESSION_TYPE = "redis" PYMYSQL_POOL = PooledDB( creator=pymysql, # 使用链接数据库的模块 maxconnections=6, # 连接池允许的最大连接数,0和None表示不限制连接数 mincached=2, # 初始化时,链接池中至少创建的空闲的链接,0表示不创建 maxcached=5, # 链接池中最多闲置的链接,0和None不限制 maxshared=3, # 链接池中最多共享的链接数量,0和None表示全部共享。PS: 无用,因为pymysql和MySQLdb等模块的 threadsafety都为1,所有值无论设置为多少,_maxcached永远为0,所以永远是所有链接都共享。 blocking=True, # 连接池中如果没有可用连接后,是否阻塞等待。True,等待;False,不等待然后报错 maxusage=None, # 一个链接最多被重复使用的次数,None表示无限制 setsession=[], # 开始会话前执行的命令列表。如:["set datestyle to ...", "set time zone ..."] ping=0, # ping MySQL服务端,检查是否服务可用。# 如:0 = None = never, 1 = default = whenever it is requested, 2 = when a cursor is created, 4 = when a query is executed, 7 = always host='127.0.0.1', port=3306, user='root', password='123456', database='s8day127db', charset='utf8' ) class ProductionConfig(Config): SESSION_REDIS = Redis(host='192.168.0.94', port='6379') class DevelopmentConfig(Config): SESSION_REDIS = Redis(host='127.0.0.1', port='6379') class TestingConfig(Config): pass
1.2 utils/sql.py
import pymysql from settings import Config class SQLHelper(object): @staticmethod def open(cursor): POOL = Config.PYMYSQL_POOL conn = POOL.connection() cursor = conn.cursor(cursor=cursor) return conn,cursor @staticmethod def close(conn,cursor): conn.commit() cursor.close() conn.close() @classmethod def fetch_one(cls,sql,args,cursor =pymysql.cursors.DictCursor): conn,cursor = cls.open(cursor) cursor.execute(sql, args) obj = cursor.fetchone() cls.close(conn,cursor) return obj @classmethod def fetch_all(cls,sql, args,cursor =pymysql.cursors.DictCursor): conn, cursor = cls.open(cursor) cursor.execute(sql, args) obj = cursor.fetchall() cls.close(conn, cursor) return obj
二、使用
obj = SQLHelper.fetch_one("select id,name from users where name=%(user)s and pwd=%(pwd)s", form.data)