pymysql 連接池

pymysql連接池

import pymysql
from DBUtils.PooledDB import PooledDB, SharedDBConnection
'''
連接池
'''
class MysqlPool(object):

    def __init__(self):
        self.POOL = PooledDB(
            creator=pymysql,  # 使用鏈接數據庫的模塊
            maxconnections=6,  # 連接池允許的最大連接數，0和None表示不限制連接數
            mincached=2,  # 初始化時，鏈接池中至少創建的空閑的鏈接，0表示不創建
            maxcached=5,  # 鏈接池中最多閑置的鏈接，0和None不限制
            maxshared=3,
            # 鏈接池中最多共享的鏈接數量，0和None表示全部共享。PS: 無用，因為pymysql和MySQLdb等模塊的 threadsafety都為1，所有值無論設置為多少，_maxcached永遠為0，所以永遠是所有鏈接都共享。
            blocking=True,  # 連接池中如果沒有可用連接后，是否阻塞等待。True，等待；False，不等待然后報錯
            maxusage=None,  # 一個鏈接最多被重復使用的次數，None表示無限制
            setsession=[],  # 開始會話前執行的命令列表。如：["set datestyle to ...", "set time zone ..."]
            ping=0,
            # ping MySQL服務端，檢查是否服務可用。# 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):
        '''
        啟用單例模式
        :param args:
        :param kw:
        :return:
        '''
        if not hasattr(cls, '_instance'):
            cls._instance = object.__new__(cls)
        return cls._instance

    def connect(self):
        '''
        啟動連接
        :return:
        '''
        conn = self.POOL.connection()
        cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)
        return conn, cursor

    def connect_close(self,conn, cursor):
        '''
        關閉連接
        :param conn:
        :param cursor:
        :return:
        '''
        cursor.close()
        conn.close()

    def fetch_all(self,sql, args):
        '''
        批量查詢
        :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):
        '''
        查詢單條數據
        :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):
        '''
        插入數據
        :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

#實例化
mp=MysqlPool()
'''
查詢單條
'''
username='admin'
data = mp.fetch_one("select id,nickname from userinfo where user=%s",(username,))
print(data)
'''
批量讀取

'''
data = mp.fetch_all("select * from record where user_id=%s",(1,))
print(data)
'''
插入數據
'''

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