python3 实现mysql数据库连接池的示例代码

# -*- coding: UTF-8 -*-
import pymysql

# 数据库信息
DB_TEST_HOST = "127.0.0.1"
DB_TEST_PORT = 3306
DB_TEST_DBNAME = "ball"
DB_TEST_USER = "root"
DB_TEST_PASSWORD = "123456"

# 数据库连接编码
DB_CHARSET = "utf8"

# mincached : 启动时开启的闲置连接数量(缺省值 0 开始时不创建连接)
DB_MIN_CACHED = 10

# maxcached : 连接池中允许的闲置的最多连接数量(缺省值 0 代表不闲置连接池大小)
DB_MAX_CACHED = 10

# maxshared : 共享连接数允许的最大数量(缺省值 0 代表所有连接都是专用的)如果达到了最大数量,被请求为共享的连接将会被共享使用
DB_MAX_SHARED = 20

# maxconnecyions : 创建连接池的最大数量(缺省值 0 代表不限制)
DB_MAX_CONNECYIONS = 100

# blocking : 设置在连接池达到最大数量时的行为(缺省值 0 或 False 代表返回一个错误<toMany......> 其他代表阻塞直到连接数减少,连接被分配)
DB_BLOCKING = True

# maxusage : 单个连接的最大允许复用次数(缺省值 0 或 False 代表不限制的复用).当达到最大数时,连接会自动重新连接(关闭和重新打开)
DB_MAX_USAGE = 0

# setsession : 一个可选的SQL命令列表用于准备每个会话，如["set datestyle to german", ...]
DB_SET_SESSION = None

# creator : 使用连接数据库的模块
DB_CREATOR = pymysql

from DBUtils.PooledDB import PooledDB
import db_config as config

"""
@功能：创建数据库连接池
"""


class MyConnectionPool(object):
    __pool = None

    # def __init__(self):
    #     self.conn = self.__getConn()
    #     self.cursor = self.conn.cursor()

    # 创建数据库连接conn和游标cursor
    def __enter__(self):
        self.conn = self.__getconn()
        self.cursor = self.conn.cursor()

    # 创建数据库连接池
    def __getconn(self):
        if self.__pool is None:
            self.__pool = PooledDB(
                creator=config.DB_CREATOR,
                mincached=config.DB_MIN_CACHED,
                maxcached=config.DB_MAX_CACHED,
                maxshared=config.DB_MAX_SHARED,
                maxconnections=config.DB_MAX_CONNECYIONS,
                blocking=config.DB_BLOCKING,
                maxusage=config.DB_MAX_USAGE,
                setsession=config.DB_SET_SESSION,
                host=config.DB_TEST_HOST,
                port=config.DB_TEST_PORT,
                user=config.DB_TEST_USER,
                passwd=config.DB_TEST_PASSWORD,
                db=config.DB_TEST_DBNAME,
                use_unicode=False,
                charset=config.DB_CHARSET
            )
        return self.__pool.connection()

    # 释放连接池资源
    def __exit__(self, exc_type, exc_val, exc_tb):
        self.cursor.close()
        self.conn.close()

    # 关闭连接归还给链接池
    # def close(self):
    #     self.cursor.close()
    #     self.conn.close()

    # 从连接池中取出一个连接
    def getconn(self):
        conn = self.__getconn()
        cursor = conn.cursor()
        return cursor, conn


# 获取连接池,实例化
def get_my_connection():
    return MyConnectionPool()

from db_dbutils_init import get_my_connection

"""执行语句查询有结果返回结果没有返回0；增/删/改返回变更数据条数，没有返回0"""


class MySqLHelper(object):
    def __init__(self):
        self.db = get_my_connection()  # 从数据池中获取连接

    def __new__(cls, *args, **kwargs):
        if not hasattr(cls, 'inst'):  # 单例
            cls.inst = super(MySqLHelper, cls).__new__(cls, *args, **kwargs)
        return cls.inst

    # 封装执行命令
    def execute(self, sql, param=None, autoclose=False):
        """
        【主要判断是否有参数和是否执行完就释放连接】
        :param sql: 字符串类型，sql语句
        :param param: sql语句中要替换的参数"select %s from tab where id=%s" 其中的%s就是参数
        :param autoclose: 是否关闭连接
        :return: 返回连接conn和游标cursor
        """
        cursor, conn = self.db.getconn()  # 从连接池获取连接
        count = 0
        try:
            # count : 为改变的数据条数
            if param:
                count = cursor.execute(sql, param)
            else:
                count = cursor.execute(sql)
            conn.commit()
            if autoclose:
                self.close(cursor, conn)
        except Exception as e:
            pass
        return cursor, conn, count

    # 执行多条命令
    # def executemany(self, lis):
    #     """
    #     :param lis: 是一个列表，里面放的是每个sql的字典'[{"sql":"xxx","param":"xx"}....]'
    #     :return:
    #     """
    #     cursor, conn = self.db.getconn()
    #     try:
    #         for order in lis:
    #             sql = order['sql']
    #             param = order['param']
    #             if param:
    #                 cursor.execute(sql, param)
    #             else:
    #                 cursor.execute(sql)
    #         conn.commit()
    #         self.close(cursor, conn)
    #         return True
    #     except Exception as e:
    #         print(e)
    #         conn.rollback()
    #         self.close(cursor, conn)
    #         return False

    # 释放连接
    def close(self, cursor, conn):
        """释放连接归还给连接池"""
        cursor.close()
        conn.close()

    # 查询所有
    def selectall(self, sql, param=None):
        try:
            cursor, conn, count = self.execute(sql, param)
            res = cursor.fetchall()
            return res
        except Exception as e:
            print(e)
            self.close(cursor, conn)
            return count

    # 查询单条
    def selectone(self, sql, param=None):
        try:
            cursor, conn, count = self.execute(sql, param)
            res = cursor.fetchone()
            self.close(cursor, conn)
            return res
        except Exception as e:
            print("error_msg:", e.args)
            self.close(cursor, conn)
            return count

    # 增加
    def insertone(self, sql, param):
        try:
            cursor, conn, count = self.execute(sql, param)
            # _id = cursor.lastrowid()  # 获取当前插入数据的主键id，该id应该为自动生成为好
            conn.commit()
            self.close(cursor, conn)
            return count
            # 防止表中没有id返回0
            # if _id == 0:
            #     return True
            # return _id
        except Exception as e:
            print(e)
            conn.rollback()
            self.close(cursor, conn)
            return count

    # 增加多行
    def insertmany(self, sql, param):
        """
        :param sql:
        :param param: 必须是元组或列表[(),()]或（（），（））
        :return:
        """
        cursor, conn, count = self.db.getconn()
        try:
            cursor.executemany(sql, param)
            conn.commit()
            return count
        except Exception as e:
            print(e)
            conn.rollback()
            self.close(cursor, conn)
            return count

    # 删除
    def delete(self, sql, param=None):
        try:
            cursor, conn, count = self.execute(sql, param)
            self.close(cursor, conn)
            return count
        except Exception as e:
            print(e)
            conn.rollback()
            self.close(cursor, conn)
            return count

    # 更新
    def update(self, sql, param=None):
        try:
            cursor, conn, count = self.execute(sql, param)
            conn.commit()
            self.close(cursor, conn)
            return count
        except Exception as e:
            print(e)
            conn.rollback()
            self.close(cursor, conn)
            return count


if __name__ == '__main__':
    db = MySqLHelper()
    # # 查询单条
    # sql1 = 'select * from userinfo where name=%s'
    # args = 'python'
    # ret = db.selectone(sql=sql1, param=args)
    # print(ret)  # (None, b'python', b'123456', b'0')
    # 增加单条
    # sql2 = 'insert into userinfo (name,password) VALUES (%s,%s)'
    # ret = db.insertone(sql2, ('old2','22222'))
    # print(ret)
    # 增加多条
    # sql3 = 'insert into userinfo (name,password) VALUES (%s,%s)'
    # li = li = [
    #     ('分省', '123'),
    #     ('到达','456')
    # ]
    # ret = db.insertmany(sql3,li)
    # print(ret)
    # 删除
    # sql4 = 'delete from  userinfo WHERE name=%s'
    # args = 'xxxx'
    # ret = db.delete(sql4, args)
    # print(ret)
    # 更新
    # sql5 = r'update userinfo set password=%s WHERE name LIKE %s'
    # args = ('993333993', '%old%')
    # ret = db.update(sql5, args)
    # print(ret)

pip3 install DBUtils

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import pymysql, os, configparser
from pymysql.cursors import DictCursor
from DBUtils.PooledDB import PooledDB


class Config(object):
    """
    # Config().get_content("user_information")

    配置文件里面的参数
    [notdbMysql]
    host = 192.168.1.101
    port = 3306
    user = root
    password = python123
    """

    def __init__(self, config_filename="myProjectConfig.cnf"):
        file_path = os.path.join(os.path.dirname(__file__), config_filename)
        self.cf = configparser.ConfigParser()
        self.cf.read(file_path)

    def get_sections(self):
        return self.cf.sections()

    def get_options(self, section):
        return self.cf.options(section)

    def get_content(self, section):
        result = {}
        for option in self.get_options(section):
            value = self.cf.get(section, option)
            result[option] = int(value) if value.isdigit() else value
        return result


class BasePymysqlPool(object):
    def __init__(self, host, port, user, password, db_name=None):
        self.db_host = host
        self.db_port = int(port)
        self.user = user
        self.password = str(password)
        self.db = db_name
        self.conn = None
        self.cursor = None


class MyPymysqlPool(BasePymysqlPool):
    """
    MYSQL数据库对象，负责产生数据库连接 , 此类中的连接采用连接池实现获取连接对象：conn = Mysql.getConn()
            释放连接对象;conn.close()或del conn
    """
    # 连接池对象
    __pool = None

    def __init__(self, conf_name=None):
        self.conf = Config().get_content(conf_name)
        super(MyPymysqlPool, self).__init__(**self.conf)
        # 数据库构造函数，从连接池中取出连接，并生成操作游标
        self._conn = self.__getConn()
        self._cursor = self._conn.cursor()

    def __getConn(self):
        """
        @summary: 静态方法，从连接池中取出连接
        @return MySQLdb.connection
        """
        if MyPymysqlPool.__pool is None:
            __pool = PooledDB(creator=pymysql,
                              mincached=1,
                              maxcached=20,
                              host=self.db_host,
                              port=self.db_port,
                              user=self.user,
                              passwd=self.password,
                              db=self.db,
                              use_unicode=False,
                              charset="utf8",
                              cursorclass=DictCursor)
        return __pool.connection()

    def getAll(self, sql, param=None):
        """
        @summary: 执行查询，并取出所有结果集
        @param sql:查询ＳＱＬ，如果有查询条件，请只指定条件列表，并将条件值使用参数[param]传递进来
        @param param: 可选参数，条件列表值（元组/列表）
        @return: result list(字典对象)/boolean 查询到的结果集
        """
        if param is None:
            count = self._cursor.execute(sql)
        else:
            count = self._cursor.execute(sql, param)
        if count > 0:
            result = self._cursor.fetchall()
        else:
            result = False
        return result

    def getOne(self, sql, param=None):
        """
        @summary: 执行查询，并取出第一条
        @param sql:查询ＳＱＬ，如果有查询条件，请只指定条件列表，并将条件值使用参数[param]传递进来
        @param param: 可选参数，条件列表值（元组/列表）
        @return: result list/boolean 查询到的结果集
        """
        if param is None:
            count = self._cursor.execute(sql)
        else:
            count = self._cursor.execute(sql, param)
        if count > 0:
            result = self._cursor.fetchone()
        else:
            result = False
        return result

    def getMany(self, sql, num, param=None):
        """
        @summary: 执行查询，并取出num条结果
        @param sql:查询ＳＱＬ，如果有查询条件，请只指定条件列表，并将条件值使用参数[param]传递进来
        @param num:取得的结果条数
        @param param: 可选参数，条件列表值（元组/列表）
        @return: result list/boolean 查询到的结果集
        """
        if param is None:
            count = self._cursor.execute(sql)
        else:
            count = self._cursor.execute(sql, param)
        if count > 0:
            result = self._cursor.fetchmany(num)
        else:
            result = False
        return result

    def insertMany(self, sql, values):
        """
        @summary: 向数据表插入多条记录
        @param sql:要插入的ＳＱＬ格式
        @param values:要插入的记录数据tuple(tuple)/list[list]
        @return: count 受影响的行数
        """
        count = self._cursor.executemany(sql, values)
        return count

    def __query(self, sql, param=None):
        if param is None:
            count = self._cursor.execute(sql)
        else:
            count = self._cursor.execute(sql, param)
        return count

    def update(self, sql, param=None):
        """
        @summary: 更新数据表记录
        @param sql: ＳＱＬ格式及条件，使用(%s,%s)
        @param param: 要更新的  值 tuple/list
        @return: count 受影响的行数
        """
        return self.__query(sql, param)

    def insert(self, sql, param=None):
        """
        @summary: 更新数据表记录
        @param sql: ＳＱＬ格式及条件，使用(%s,%s)
        @param param: 要更新的  值 tuple/list
        @return: count 受影响的行数
        """
        return self.__query(sql, param)

    def delete(self, sql, param=None):
        """
        @summary: 删除数据表记录
        @param sql: ＳＱＬ格式及条件，使用(%s,%s)
        @param param: 要删除的条件 值 tuple/list
        @return: count 受影响的行数
        """
        return self.__query(sql, param)

    def begin(self):
        """
        @summary: 开启事务
        """
        self._conn.autocommit(0)

    def end(self, option='commit'):
        """
        @summary: 结束事务
        """
        if option == 'commit':
            self._conn.commit()
        else:
            self._conn.rollback()

    def dispose(self, isEnd=1):
        """
        @summary: 释放连接池资源
        """
        if isEnd == 1:
            self.end('commit')
        else:
            self.end('rollback')
        self._cursor.close()
        self._conn.close()


if __name__ == '__main__':
    mysql = MyPymysqlPool("notdbMysql")

    sqlAll = "select * from myTest.aa;"
    result = mysql.getAll(sqlAll)
    print(result)

    sqlAll = "select * from myTest.aa;"
    result = mysql.getMany(sqlAll, 2)
    print(result)

    result = mysql.getOne(sqlAll)
    print(result)

    # mysql.insert("insert into myTest.aa set a=%s", (1))

    # 释放资源
    mysql.dispose()