python dbutils 簡介及准備工作
DBUtils是一套Python數據庫連接池包，並允許對非線程安全的數據庫接口進行線程安全包裝。DBUtils來自Webware for Python。
DBUtils提供兩種外部接口：
- PersistentDB ：提供線程專用的數據庫連接，並自動管理連接。
- PooledDB ：提供線程間可共享的數據庫連接，並自動管理連接。
需要庫
1、DBUtils pip install DBUtils
2、pymysql pip install pymysql/MySQLdb
創建DButils組件
db_config.py 配置文件
# -*- coding: UTF-8 -*-
import pymysql
# 數據庫信息
DB_TEST_HOST = "127.0.0.1"
DB_TEST_PORT = 3306
DB_TEST_DBNAME = "ball"
DB_TEST_USER = "root"
DB_TEST_PASSWORD = "123456"
# 數據庫連接編碼
DB_CHARSET = "utf8"
# mincached : 啟動時開啟的閑置連接數量(缺省值 0 開始時不創建連接)
DB_MIN_CACHED = 10
# maxcached : 連接池中允許的閑置的最多連接數量(缺省值 0 代表不閑置連接池大小)
DB_MAX_CACHED = 10
# maxshared : 共享連接數允許的最大數量(缺省值 0 代表所有連接都是專用的)如果達到了最大數量,被請求為共享的連接將會被共享使用
DB_MAX_SHARED = 20
# maxconnecyions : 創建連接池的最大數量(缺省值 0 代表不限制)
DB_MAX_CONNECYIONS = 100
# blocking : 設置在連接池達到最大數量時的行為(缺省值 0 或 False 代表返回一個錯誤<toMany......> 其他代表阻塞直到連接數減少,連接被分配)
DB_BLOCKING = True
# maxusage : 單個連接的最大允許復用次數(缺省值 0 或 False 代表不限制的復用).當達到最大數時,連接會自動重新連接(關閉和重新打開)
DB_MAX_USAGE = 0
# setsession : 一個可選的SQL命令列表用於准備每個會話，如["set datestyle to german", ...]
DB_SET_SESSION = None
# creator : 使用連接數據庫的模塊
DB_CREATOR = pymysql
db_dbutils_init.py 創建數據池初始化
from DBUtils.PooledDB import PooledDB
import db_config as config
"""
@功能：創建數據庫連接池
"""
class MyConnectionPool(object):
__pool = None
# def __init__(self):
# self.conn = self.__getConn()
# self.cursor = self.conn.cursor()
# 創建數據庫連接conn和游標cursor
def __enter__(self):
self.conn = self.__getconn()
self.cursor = self.conn.cursor()
# 創建數據庫連接池
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()
# 釋放連接池資源
def __exit__(self, exc_type, exc_val, exc_tb):
self.cursor.close()
self.conn.close()
# 關閉連接歸還給鏈接池
# def close(self):
# self.cursor.close()
# self.conn.close()
# 從連接池中取出一個連接
def getconn(self):
conn = self.__getconn()
cursor = conn.cursor()
return cursor, conn
# 獲取連接池,實例化
def get_my_connection():
return MyConnectionPool()
制作mysqlhelper.py
from db_dbutils_init import get_my_connection
"""執行語句查詢有結果返回結果沒有返回0；增/刪/改返回變更數據條數，沒有返回0"""
class MySqLHelper(object):
def __init__(self):
self.db = get_my_connection() # 從數據池中獲取連接
def __new__(cls, *args, **kwargs):
if not hasattr(cls, 'inst'): # 單例
cls.inst = super(MySqLHelper, cls).__new__(cls, *args, **kwargs)
return cls.inst
# 封裝執行命令
def execute(self, sql, param=None, autoclose=False):
"""
【主要判斷是否有參數和是否執行完就釋放連接】
:param sql: 字符串類型，sql語句
:param param: sql語句中要替換的參數"select %s from tab where id=%s" 其中的%s就是參數
:param autoclose: 是否關閉連接
:return: 返回連接conn和游標cursor
"""
cursor, conn = self.db.getconn() # 從連接池獲取連接
count = 0
try:
# count : 為改變的數據條數
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
# 執行多條命令
# def executemany(self, lis):
# """
# :param lis: 是一個列表，里面放的是每個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
# 釋放連接
def close(self, cursor, conn):
"""釋放連接歸還給連接池"""
cursor.close()
conn.close()
# 查詢所有
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
# 查詢單條
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() # 獲取當前插入數據的主鍵id，該id應該為自動生成為好
conn.commit()
self.close(cursor, conn)
return count
# 防止表中沒有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: 必須是元組或列表[(),()]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
# 刪除
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()
# # 查詢單條
# 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')
# 增加單條
# sql2 = 'insert into userinfo (name,password) VALUES (%s,%s)'
# ret = db.insertone(sql2, ('old2','22222'))
# print(ret)
# 增加多條
# sql3 = 'insert into userinfo (name,password) VALUES (%s,%s)'
# li = li = [
# ('分省', '123'),
# ('到達','456')
# ]
# ret = db.insertmany(sql3,li)
# print(ret)
# 刪除
# 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)