二.MySQL数据驱动

1.数据库查询

#!/user/bin/env python
# coding:utf-8
# Author:shenqiang
import pymysql
def connectMysql():
    try:
        '''链接数据库'''
        connect = pymysql.connect(
            host='127.0.0.1',
            user='root',
            password='shen6409175',
            db='students'
        )
    except Exception as  e:
        return e.args
    else:
        '''创建游标'''
        cur = connect.cursor()
        '''SQL语句分离'''
        # sql = 'select * from student where id = %s'
        # params = (2,)
        # '''查重'''
        # cur.execute(sql,params)
        # '''单条数据的查询'''
        # data = cur.fetchone()
        # return datas
        sql = 'select * from student'
        '''查重'''
        cur.execute(sql)
        '''多条数据查询'''
        datas = cur.fetchall()
        '''方法一，遍历'''
        # for data in datas:
        #     print(data)
        '''方法二，列表推倒式'''
        db = [data for data in datas]
        return db
    finally:
        # 关闭游标和链接
        cur.close()
        connect.close()
print(connectMysql())

　　

2.数据库插入数据

#!/user/bin/env python
#coding:utf-8
#Author:shenqiang
import pymysql
def connectMysql():
    try:
        '''链接数据库'''
        connect = pymysql.connect(
            host='127.0.0.1',
            user='root',
            password='shen6409175',
            db='students'
        )
    except Exception as  e:
        return e.args
    else:
        '''创建游标'''
        cur = connect.cursor()
        '''导入数据'''
        # 单条语句的插入
        # sql = 'insert into student values(%s,%s,%s,%s);'
        # params = (6,'沈～','24','南京')
        '''批量插入数据'''
        sql = 'insert into student values(%s,%s,%s,%s);'
        params = [
            (7, '沈～', '24', '南京'),
            (8, '沈～', '24', '南京')
            ]
        cur.executemany(sql,params)
        '''insert后必须要commit()'''
        connect.commit()
    finally:
        # 关闭游标和链接
        cur.close()
        connect.close()
connectMysql()

　　

3.数据库删除数据

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Author : shenqiang
import pymysql
def connectMysqlDelect():
    try:
        '''连接数据库'''
        connectMysqlDelect = pymysql.Connect(
            host = '127.0.0.1',
            user = 'root',
            password = 'shen6409175',
            db = 'students',
        )
    except Exception as  e:
        print(e.args)
    else:
        '''创建游标'''
        cur = connectMysqlDelect.cursor()
        '''执行sql'''
        mysql = 'delete from student order by id desc limit 1'
        cur.execute(mysql)
        '''提交事务'''
        connectMysqlDelect.commit()
        print('success')
    finally:
        '''关闭游标和数据库'''
        cur.close()
        connectMysqlDelect.close()
connectMysqlDelect()

　　

4.一个完整的Mysql数据驱动方式

#!/user/bin/env python
#coding:utf-8
#Author:shenqiang
import pymysql
class MysqlTry:
    '''链接数据库'''
    def connectMysql(self):
        '''尝试链接数据库'''
        try:
            connect =pymysql.connect(
                host = '127.0.0.1',
                user='root',
                password='shen6409175',
                db='students'
            )
        except Exception as e:
            print(e.args)
        return connect
    def selectMysql(self,sql,params):
        '''创建游标'''
        cur = self.connectMysql().cursor()
        '''查重'''
        cur.execute(sql,params)
        '''查询'''
        result = cur.fetchall()
        '''删除游标'''
        cur.close()
        return result
def checkValid(username,age):
    opera = MysqlTry()
    sql = "select * from student where name = %s and age = %s"
    params=(username,age)
    return opera.selectMysql(sql=sql,params=params)
def checkinfo():
    username = input('请输入用户名 
')
    age = input('请输入用户年龄 
')
    result = checkValid(username,age)
    if result:
        '''关闭数据库'''
        MysqlTry().connectMysql().close()
        print('该用户在数据库中，测试通过！')
    else:
        print('该用户不在数据库中，存在bug！')
if __name__ == '__main__':
    checkinfo()