MySQL 使用连接池封装pymysql

备注：1，记得先修改连接的数据库哦，（用navicat更方便一点）；2，分开两个py文件写入，运行sqlhelper.py文件

一、在utils.py中写

import pymysql
from DBUtils.PooledDB import PooledDB

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=1,  # 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='',
    database='ziji',
    charset='utf8'
)

二、在sqlhelper.py中写入：

from utils import POOL
import pymysql

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

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

def select_one(sql, args):
    conn, cur = create_conn()
    cur.execute(sql, args)
    result = cur.fetchone()
    close_conn(conn, cur)
    return result

def select_all(sql, args):
    conn, cur = create_conn()
    cur.execute(sql, args)
    result = cur.fetchall()
    close_conn(conn, cur)
    return result

def insert_one(sql, args):
    conn, cur = create_conn()
    result = cur.execute(sql, args)
    conn.commit()
    close_conn(conn, cur)
    return result

def delete_one(sql,args):
    conn,cur = create_conn()
    result = cur.execute(sql,args)
    conn.commit()
    close_conn(conn,cur)
    return result

def update_one(sql,args):
    conn,cur = create_conn()
    result = cur.execute(sql,args)
    conn.commit()
    close_conn(conn,cur)
    return result

# sql = "insert into stu(id,name,age) VALUE (%s,%s,%s)"   #增加
# res = insert_one(sql, [2,"飞机", 28])
# print(res)

# sql = "delete from stu where name = %s"   #删除
# res = delete_one(sql, "哪吒")
# print(res)

# sql = "select * from stu"   #查询全部
# res = select_all(sql, [])
# print(res)

# sql = "select * from stu where name=%s"   #查询一条
# res = select_one(sql, "赵振伟")
# print(res)

# sql = " UPDATE stu set name=%s where name = %s"   #更新
# res = update_one(sql,("坦克","飞机"))
# print(res)

转载自：https://www.cnblogs.com/zzw731862651/articles/9605308.html