pymysql 连接池

pymysql from DBUtils.PooledDB import PooledDB, SharedDBConnection ‘‘‘ 连接池 ‘‘‘ class MysqlPool(object): def __init__(self): self.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=‘root‘, database=‘test‘, charset=‘utf8‘ ) def __new__(cls, *args, **kw): ‘‘‘ 启用单例模式 :param args: :param kw: :return: ‘‘‘ if not hasattr(cls, ‘_instance‘): cls._instance = object.__new__(cls) return cls._instance def connect(self): ‘‘‘ 启动连接 :return: ‘‘‘ conn = self.POOL.connection() cursor = conn.cursor(cursor=pymysql.cursors.DictCursor) return conn, cursor def connect_close(self,conn, cursor): ‘‘‘ 关闭连接 :param conn: :param cursor: :return: ‘‘‘ cursor.close() conn.close() def fetch_all(self,sql, args): ‘‘‘ 批量查询 :param sql: :param args: :return: ‘‘‘ conn, cursor = self.connect() cursor.execute(sql, args) record_list = cursor.fetchall() self.connect_close(conn, cursor) return record_list def fetch_one(self,sql, args): ‘‘‘ 查询单条数据 :param sql: :param args: :return: ‘‘‘ conn, cursor = self.connect() cursor.execute(sql, args) result = cursor.fetchone() self.connect_close(conn, cursor) return result def insert(self,sql, args): ‘‘‘ 插入数据 :param sql: :param args: :return: ‘‘‘ conn, cursor = self.connect() row = cursor.execute(sql, args) conn.commit() self.connect_close(conn, cursor) return row

 

操作

#实例化
mp=MysqlPool()
‘‘‘
查询单条
‘‘‘
username=‘admin‘
data = mp.fetch_one("select id,nickname from userinfo where user=%s",(username,))
print(data)
‘‘‘
批量读取

‘‘‘
data = mp.fetch_all("select * from record where user_id=%s",(1,))
print(data)
‘‘‘
插入数据
‘‘‘

data = mp.insert("insert into record(line,ctime,user_id)values(%s,%s,%s)",(22,‘2019-11-11‘,1))
print(data)

 

pymysql 连接池

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