pymysql中DButils的使用

# settings.py文件

import pymysql
from DBUtils.PooledDB import PooledDB

class Config(object):
    SALT = b"sdf1123df"
    SECRET_KEY = ‘asdf123sdfsdfsdf‘

    MAX_CONTENT_LENGTH = 1024 * 1024 * 7

    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=‘127.0.0.1‘,
        port=3306,
        user=‘root‘,
        password=‘123456‘,
        database=‘homework‘,
        charset=‘utf8‘
    )

# 在蓝图中的__init.py__文件中

from flask import Flask

def create_app():
    app = Flask(__name__)

    app.config.from_object(‘settings.Config‘)

    return app

import pymysql
from settings import Config

def connect():
    conn = Config.POOL.connection()
    cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)
    return conn,cursor

def connect_close(cursor, conn):
    cursor.close()
    conn.close()


def fetch_one(sql, args):
    conn,cursor = connect()
    cursor.execute(sql,args)
    data = cursor.fetchone()
    connect_close(cursor, conn)

    return data

def fetch_all(sql, args):
    conn,cursor = connect()
    cursor.execute(sql,args)
    data_list = cursor.fetchall()
    connect_close(cursor, conn)

    return data_list

def insert(sql,args):
    conn, cursor = connect()
    row = cursor.execute(sql, args)
    conn.commit()
    connect_close(cursor, conn)

    return row