Python MySQL database connection pool DBUtils

Not much, just go directly to the code.

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)

the above.

Refer to the use of DBUtils:

Python uses PyMysql and DBUtils to create connection pools to improve performance

DBUtils-Python database connection pool

Python database connection pool DBUtils (based on pymysql module to connect to the database)

The code of this blog post belongs to the blogger of this article, please indicate the source of the blog post.