pymysql连接池操作MySQL

pymysql连接池操作MySQL

安装：

pip install PyMySQL
pip install DBUtils

实例：

import logging
import pymysql
from dbutils.pooled_db import PooledDB


class MysqlPool:
	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
			# 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。
			maxshared=3,
			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 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
			ping=0,
			host='127.0.0.1',
			port=3306,
			user='root',
			password='123456',
			database='play_open',
			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:
		"""
		try:
			conn = self.POOL.connection()
			cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)
			return conn, cursor
		except Exception as e:
			logging.error(f'mysql connect error: {e}')

	@staticmethod
	def connect_close(conn, cursor):
		"""
		关闭连接
		:param conn:
		:param cursor:
		:return:
		"""
		try:
			cursor.close()
			conn.close()
		except Exception as e:
			logging.error(f'mysql close error: {e}')

	def fetch_all(self, sql, args=None):
		"""
		批量查询
		:param sql:
		:param args:
		:return:
		"""
		try:
			conn, cursor = self.connect()
			cursor.execute(sql, args)
			record_list = cursor.fetchall()
			self.connect_close(conn, cursor)

			return record_list
		except Exception as e:
			logging.error(f'fetchall error: {e}')

	def fetch_one(self, sql, args=None):
		"""
		查询单条数据
		:param sql:
		:param args:
		:return:
		"""
		try:
			conn, cursor = self.connect()
			cursor.execute(sql, args)
			result = cursor.fetchone()
			self.connect_close(conn, cursor)
			return result
		except Exception as e:
			logging.error(f'fetchone error: {e}')

	def insert(self, sql, args=None):
		"""
		插入数据
		:param sql:
		:param args:
		:return:
		"""
		conn, cursor = self.connect()
		try:
			row = cursor.execute(sql, args)
			conn.commit()
		except Exception as e:
			logging.error(f'insert error: {e}')
			conn.rollback()
			row = {}
		self.connect_close(conn, cursor)
		return row

	# 增加多行
	def insertmany(self, sql, param):
		"""
		:param sql:
		:param param: 必须是元组或列表[(),()]或（（），（））
		:return:
		"""
		conn, cursor = self.connect()
		try:
			row = cursor.executemany(sql, param)
			conn.commit()
		except Exception as e:
			logging.error(f'insertmany error: {e}')
			conn.rollback()
			row = "更新失败"
		self.connect_close(cursor, conn)
		return row

	# 删除
	def delete(self, sql, param=None):
		conn, cursor = self.connect()
		try:
			row = cursor.execute(sql, param)
			# conn.commit()
		except Exception as e:
			logging.error(f'delete error: {e}')
			conn.rollback()
			row = "更新失败"
		self.connect_close(cursor, conn)
		return row

	# 更新
	def update(self, sql, param=None):
		conn, cursor = self.connect()
		try:
			row = cursor.execute(sql, param)
			conn.commit()
		except Exception as e:
			logging.error(f'update error: {e}')
			conn.rollback()
			row = "更新失败"
		self.connect_close(cursor, conn)
		return row


if __name__ == '__main__':
	# 实例化
	mp = MysqlPool()
	# """
	# 查询单条
	# """
	data = mp.fetch_all("select * from domain_list where cloud='bs' and app_name!='offline' limit 10;")
	data = mp.fetch_one("select * from domain_list where cloud='bs' and app_name!='offline' limit 10;")
	print(data)

	# """
	# 批量读取
	# """
	# data = mp.fetch_all("select * from domain_list where id=%s", (1,))
	# print(data)

	# """
	# 插入数据
	# """
	# data = mp.insert("insert into domain_list(domain,status,cloud,app_name)values(%s,%s,%s,%s)", ('www.testlbl.com',"online", 'test-tx', 'damao-test'))
	# print(data)

	# 增加多条
	# sql3 = 'insert into domain_list (domain,status,cloud,app_name) VALUES (%s,%s,%s,%s)'
	# li = [
	#     ('www.testlbl1.com',"online", 'test-tx', 'damao-test'),
	#     ('www.testlbl2.com',"online", 'test-tx', 'damao-test'),
	#     ('www.testlbl3.com', "online", 'test-tx', 'damao-test')
	# ]
	# ret = mp.insertmany(sql3,li)
	# print(ret)

	# 删除(commit 注释了，如需删除取消注释)
	# sql4 = 'delete from domain_list WHERE id > %s'
	# args = 1487
	# ret = mp.delete(sql4, args)
	# print(ret)

	# 更新
	# sql5 = r'update domain_list set Code_Success_rate=%s WHERE domain=%s and app_name=%s'
	# args = ('yes', 'www.testlbl.com', 'damao-test')
	# ret = mp.update(sql5, args)
	# print(ret)

参考来源：

https://blog.csdn.net/weixin_45389126/article/details/115859808