Python之MySQL数据库连接池DBUtils

话不多少，直接上代码。

import time
import pymysql
from DBUtils.PooledDB import PooledDB, SharedDBConnection
from log import logger
from config import configs, APP_ENV


DB_HOST = configs[APP_ENV].DB_HOST
DB_PORT = configs[APP_ENV].DB_PORT
DB_USER = configs[APP_ENV].DB_USER
DB_PASSWORD = configs[APP_ENV].DB_PASSWORD
DB_DEFAULT = configs[APP_ENV].DB_DEFAULT
DB_CHARSET = configs[APP_ENV].DB_CHARSET


def exe_time(func):
	def new_func(*args, **args2):
		t0 = time.time()
		t0local = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime())
		back = func(*args, **args2)
		t1 = time.time()
		t1local = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime())
		msg = "Function: %s, start: @%s, end: @%s,  elapsed: @%.4fs." % (func.__name__, t0local, t1local, t1 - t0)
		logger.info(msg)
		return back
	return new_func


class MSC(object):

	"""the class to connect mysql database and execute sql"""
	def __init__(self, host, port, dbuser, password, db, charset):
		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=host,
			port=int(port),
			user=dbuser,
			password=password,
			database=db,
			charset=charset
		)

	def get_cursor(self):
		try:
			conn = self.pool.connection()
			cursor = conn.cursor()
		except Exception as e:
			logger.error("Database Connection error: " + str(e))
			return None
		return conn, cursor

	def get_cursor2(self):
		try:
			conn = self.pool.connection()
			cursor = conn.cursor(pymysql.cursors.SSDictCursor)
		except Exception as e:
			logger.error("Database Connection error: " + str(e))
			return None
		return conn, cursor

	@exe_time
	def execute(self, sql, param=None):
		"""执行单条SQL。用于：delete、update、insert。

		:param sql: 标准SQL
		:param param: SQL参数
		:return: 影响行数
		"""
		logger.info(sql)
		conn, cursor = self.get_cursor()
		try:
			cursor.execute(sql, param)
			conn.commit()
			affected_row = cursor.rowcount
		except Exception as e:
			logger.error("mysql execute error: " + str(e))
			raise Exception("mysql execute error: " + str(e))
		finally:
			cursor.close()
			conn.close()
		return affected_row

	@exe_time
	def executemany(self, sql, param=None):
		"""执行多条SQL。

		:param sql: 标准SQL
		:param param: SQL参数
		:return: 影响行数
		"""
		logger.info(sql)
		conn, cursor = self.get_cursor()
		try:
			cursor.executemany(sql, param)
			conn.commit()
			affected_row = cursor.rowcount
		except Exception as e:
			logger.error("mysql execute error: " + str(e))
			raise Exception("mysql execute error: " + str(e))
		finally:
			cursor.close()
			conn.close()
		return affected_row

	@exe_time
	def query(self, sql):
		"""查询SQL。执行select语句。

		:param sql: 标准SQL
		:return: 返回元组类型的结构
		"""
		logger.info(sql)
		conn, cursor = self.get_cursor()
		try:
			cursor.execute(sql, None)
			result = cursor.fetchall()
		except Exception as e:
			logger.error("mysql query error: " + str(e))
			return None
		finally:
			cursor.close()
			conn.close()
		return result

	@exe_time
	def query2(self, sql):
		"""查询SQL。执行select语句。

		:param sql: 标准SQL
		:return: 返回SQL执行的记录，列表类型的结构，键值对形式
		"""
		logger.info(sql)
		conn, cursor = self.get_cursor2()
		try:
			cursor.execute(sql, None)
			result = cursor.fetchall()
		except Exception as e:
			logger.error("database query error: " + str(e))
			return None
		finally:
			cursor.close()
			conn.close()
		return result


cursor_mysql = MSC(DB_HOST, DB_PORT, DB_USER, DB_PASSWORD, DB_DEFAULT, DB_CHARSET)  # 实例化对象

insert_sql = """insert into users(username, password) values('zhangsan', '123456');"""
print(insert_sql)
cursor_mysql.execute(insert_sql)

select_sql = """select * from users;"""
res = cursor_mysql.query(select_sql)
print(res)

select_sql = """select * from users;"""
res2 = cursor_mysql.query2(select_sql)
print(res2)

以上。

参考大佬DBUtils使用：

Python 使用 PyMysql、DBUtils 创建连接池，提升性能

DBUtils - Python数据库连接池

Python数据库连接池DBUtils（基于pymysql模块连接数据库）

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