python同时连接两个数据库，信息进行相互补充。

需求分析：

连接外网的sf数据库，对本机的已经配准单号图片的数据库进行信息补全。外网数据库要求性能，及时释放连接。

方案：

pymysql释放连接不彻底，外网数据库使用DBUtils
本机使用pysql简单连接。

"""
数据库工具类
# """
import pymysql
from DBUtils.PooledDB import PooledDB, SharedDBConnection
from DBUtils.PersistentDB import PersistentDB, PersistentDBError, NotSupportedError

config = {
     
    'host': '192.168******',
    'port': 3308,
    'database': '******',
    'user': 'root',
    'password': '********',
    'charset': 'utf8'
}

#链接1 需要同步的数据库
connect1 = pymysql.Connect(
    host='localhost',
    port=3306,
    user='root',
    passwd='****',
    db='******',
    charset='utf8'
)


def get_db_pool(is_mult_thread):
    if is_mult_thread:
        poolDB = PooledDB(
            # 指定数据库连接驱动
            creator=pymysql,
            # 连接池允许的最大连接数,0和None表示没有限制
            maxconnections=3,
            # 初始化时,连接池至少创建的空闲连接,0表示不创建
            mincached=2,
            # 连接池中空闲的最多连接数,0和None表示没有限制
            maxcached=5,
            # 连接池中最多共享的连接数量,0和None表示全部共享(其实没什么卵用)
            maxshared=3,
            # 连接池中如果没有可用共享连接后,是否阻塞等待,True表示等等,
            # False表示不等待然后报错
            blocking=True,
            # 开始会话前执行的命令列表
            setsession=[],
            # ping Mysql服务器检查服务是否可用
            ping=0,
            **config
        )
    else:
        poolDB = PersistentDB(
            # 指定数据库连接驱动
            creator=pymysql,
            # 一个连接最大复用次数,0或者None表示没有限制,默认为0
            maxusage=1000,
            **config
        )
    return poolDB

def start_syg(count):
    #添加信息，发件人没有
    sql = "SELECT * FROM logistics where sender_name is null"
    try:
        cursor1.execute(sql)
        # print(type(cursor1.fetchall()))
        if cursor1.fetchall:
            for row in cursor1.fetchall():
                #print(row)
                #待插入数据
                package_id = row[1]
                # package_pro = row[5]
                # send_time =row[6]
                # sender_name =row[7]
                # sender_addr =row[8]
                # sender_phone =row[9]
                # receiver_name =row[10]
                # receiver_addr =row[11]
                # receiver_phone =row[12]

                #查询表2信息
                sql2="SELECT * FROM widetable where billNo = '%s'" % (package_id)
                print(sql2)
                try:
                    cursor2.execute(sql2)

                    if cursor2.fetchone:
                        row2 = cursor2.fetchone()
                        print(row2)
                        package_pro =str(row2[6])
                        send_time =str(row2[1])
                        sender_name =str(row2[8])
                        sender_addr =str(row2[12])
                        sender_phone =str(row2[9])
                        receiver_name =str(row2[13])
                        receiver_addr =str(row2[15])
                        receiver_phone =str(row2[17])
                        print(package_pro,sender_phone,sender_addr,sender_name,send_time,receiver_phone,receiver_addr,receiver_name)
                        #更新不用写括号！改了半天
                        sql3 = "UPDATE logistics SET package_property='%s',package_send_time='%s',sender_name='%s',sender_address='%s',sender_phone='%s',receiver_name ='%s',receiver_address='%s',receiver_phone='%s'where package_id = '%s'" % (package_pro,send_time,sender_name,sender_addr,sender_phone,receiver_name,receiver_addr,receiver_phone,package_id)
                        #print(sql3)
                        #是否抓取一下异常？
                        cursor1.execute(sql3)
                        connect1.commit()
                        print(11121212211111111)
                        count+=1
                        print("########################表1已更新",count,"条数据#########################")

                        #connect1.rollback()

                except:
                    print("表2无匹配数据")
        else:
            print('目前待同步表没有内容')
    except:
        pass

if __name__ == '__main__':
    # 以单线程的方式初始化数据库连接池
    db_pool = get_db_pool(False)
    # 从数据库连接池中取出一条连接
    connect2 = db_pool.connection()
    #两个执行体
    cursor1 = connect1.cursor()
    cursor2 = connect2.cursor()
    #记录添加数据
    count = 0
    print('开始执行')
    start_syg(count)
    print('执行结束')

    cursor1.close()
    connect1.close()
    cursor2.close()
    connect2.close()

执行结果