Mysql数据库工具类
新建MysqlHelper/DBUtils,实现操作数据库代码的 复用!
分析
数据库操作分为两类
非查询
增加,删,修改 都是非查询!
实现方法: execute(sql语句,不同参数列表)
增删改区别: sql语句不同, 参数个数不同!--->可以独一个共用方法,把sql和参数传过来! # 增删改功能都返回: 影响行数据!
def my_execute(sql,params):
,,,,
return num
查询
查询1条 游标.fetchone()
查询多条 游标.fetchall()
连接数据库相关参数所有功能都需要！–>放在类的初始化方法中init
获取数据库连接: 所有方法都需要!—>可以独立出来!
init方法,负责初始连接数据库需要各种参数!
class MysqlHelper():
# 初始化方法
def init(self,主机地址,端口,用户名,密码,字符集)
self.主机地址=主机地址
....
def my_execute(sql,prames):
pass
def connect():
......
使用
db = MysqlHelper(Ip地址,端口.用户名,密码.字符集)
增加
num =db.my_execute(sql语句,参数列表)
if num>0:
print('成功')
else:
print('失败')
代码实现
import pymysql # 导入数据库驱动模块!
class MysqlHelper():
#db = MysqlHelper('39.98.39.173',13306,'root','root','1909C2')
def init(self,host,port,user,passwd,db,charset='utf8'):
self.host= host
self.port = port
self.user = user
self.passwd = passwd
self.db = db
self.charset=charset
#self.conn = None
def connect(self):
'''功能1: 获取连接'''
self.conn = pymysql.connect(host=self.host,port=self.port,user=self.user,passwd=self.passwd,db=sel f.db,charset=self.charset)
self.cursor =self.conn.cursor()
def close(self):
'''功能2:释放资源'''
self.cursor.close() #关游标
self.conn.close()# 关连接
def my_execute(self,sql,params):
'''增删改通用功能
:param sql: sql语句
:param params: 参数列表
:return: num 影响行数 '''
num =0
# 1. 打开连接
self.connect()
num = self.cursor.execute(sql,params)
self.conn.commit()
self.close() #释放资源
return num
def get_one(self,sql,params):
''' 查询1条
:param sql: sql语句
:param params: 参数列表
:return: 1条结果 '''
result =None
#1.打开链接
self.connect()
# 2.执行查询
self.cursor.execute(sql,params)
# 3 逐行抓取
result = self.cursor.fetchone()
#4.释放资源
self.close()
return result
def get_all(self, sql, params):
''' 查询所有
:param sql: sql语句
:param params: 参数列表
:return: 1条结果 '''
result = ()
self.connect()
self.cursor.execute(sql, params)
result = self.cursor.fetchall()
self.close()
return result
if name == 'main':
# 实例化对象
db = MysqlHelper('39.98.39.173',13306,'root','root','1909C2')
#增加
#insert into students values(default,'张A','男',20,'2020-11-05','176','山西')
''' sql = 'insert into students values(default,%s,%s,%s,%s,%s,%s)'
params=['张B','男',20,'2020-11-05','176','山西']
num = db.my_execute(sql,params)
print(num) '''
# 查1条
sql = 'select * from students where age =%s'
params=(12)
result =db.get_one(sql,params) #((),())
print(result)
studetns = db.get_all(sql,params)
for stu in studetns:
print(f'名字:{stu[1]}')
错误
[SQL] insert into students values(default,'张三','男',20,'2020-11-05','176','山西')
[Err] 1062 - Duplicate entry '张三' for key 'name' # 名字重复! Duplicate:重复!
学生管理系统
from MysqlHelper import MysqlHelper #导入mysql工具类
from datetime import datetime #导入日期模块
def add_stu():
# 1.实例化工具类
db = MysqlHelper('39.98.39.173', 13306, 'root', 'root', '1909C2')
# 2. 调用增加方法
#insert into students values(default,'张A','男',20,'2020-11-05','176','山西')
sql = 'insert into students values(default,%s,%s,%s,%s,%s,%s)'
params=['张D','男',20,datetime.now(),'176','山西']
num =db.my_execute(sql,params)
return num
def del_stu(name):
'''删除'''
db = MysqlHelper('39.98.39.173', 13306, 'root', 'root', '1909C2')
sql = 'delete from students where name =%s'
params=[name]
num = db.my_execute(sql,params)
return num
def update_stu(oldName,name,age,sex,phone,addr):
db = MysqlHelper('39.98.39.173', 13306, 'root', 'root', '1909C2')
sql ='update students set name =%s,age=%s,sex=%s,phone=%s,addr=%s where name = %s'
params = (name,age,sex,phone,addr,oldName)
return db.my_execute(sql,params)
def get_all():
db = MysqlHelper('39.98.39.173', 13306, 'root', 'root', '1909C2')
sql = 'select * from students'
students = db.get_all(sql,None)
for stu in students:
print(f'名字:{stu[1]},性别:{stu[2]}')
def get_by_name(name):
db = MysqlHelper('39.98.39.173', 13306, 'root', 'root', '1909C2')
sql = 'select * from students where name =%s'
params = (name) students = db.get_all(sql,params)
for stu in students:
print(f'名字:{stu[1]},性别:{stu[2]}')
if name == 'main':
'''增加
if add_stu() > 0:
print('成功')
else:
print('失败') '''
''' 删除
if del_stu('张D') >0:
print('成功')
else:
print('失败') '''
'''修改
if update_stu('zhang',"张小三",40,'女','110110','陕西')>0:
print('修改成功')
else:print('失败')
'''
get_all()