增加
- 创建testInsert.py文件，向学生表中插入一条数据
import pymysql
try:
conn=MySQLdb.connect(host='localhost',port=3306,db='test1',user='root',passwd='mysql',charset='utf8')
cs1=conn.cursor()
count=cs1.execute("insert into students(sname) values('张良')")
print(count)
conn.commit()
cs1.close()
conn.close()
except Exception as e:
print(e)
修改
- 创建testUpdate.py文件，修改学生表的一条数据
import pymysql
try:
conn=MySQLdb.connect(host='localhost',port=3306,db='test1',user='root',passwd='mysql',charset='utf8')
cs1=conn.cursor()
count=cs1.execute("update students set sname='刘邦' where id=6")
print(count)
conn.commit()
cs1.close()
conn.close()
except Exception as e:
print(e)
删除
- 创建testDelete.py文件，删除学生表的一条数据
import pymysql
try:
conn=MySQLdb.connect(host='localhost',port=3306,db='test1',user='root',passwd='mysql',charset='utf8')
cs1=conn.cursor()
count=cs1.execute("delete from students where id=6")
print(count)
conn.commit()
cs1.close()
conn.close()
except Exception as e:
print(e)
sql语句参数化
- 创建testInsertParam.py文件，向学生表中插入一条数据
import pymysql
try:
conn=MySQLdb.connect(host='localhost',port=3306,db='test1',user='root',passwd='mysql',charset='utf8')
cs1=conn.cursor()
sname=raw_input("请输入学生姓名：")
params=[sname]
count=cs1.execute('insert into students(sname) values(%s)',params)
print(count)
conn.commit()
cs1.close()
conn.close()
except Exception as e:
print(e)
其它语句
cursor对象的execute()方法，也可以用于执行create table等语句
建议在开发之初，就创建好数据库表结构，不要在这里执行
查询一行数据
- 创建testSelectOne.py文件，查询一条学生信息
import pymysql
try:
conn=MySQLdb.connect(host='localhost',port=3306,db='test1',user='root',passwd='mysql',charset='utf8')
cur=conn.cursor()
cur.execute('select * from students where id=7')
result=cur.fetchone()
print(result)
cur.close()
conn.close()
except Exception as e:
print(e)
查询多行数据
- 创建testSelectMany.py文件，查询一条学生信息
import pymysql
try:
conn=MySQLdb.connect(host='localhost',port=3306,db='test1',user='root',passwd='mysql',charset='utf8')
cur=conn.cursor()
cur.execute('select * from students')
result=cur.fetchall()
print(result)
cur.close()
conn.close()
except Exception as e:
print(e)
封装
观察前面的文件发现，除了sql语句及参数不同，其它语句都是一样的
创建MysqlHelper.py文件，定义类
import pymysql
class MysqlHelper():
def __init__(self,host,port,db,user,passwd,charset='utf8'):
self.host=host
self.port=port
self.db=db
self.user=user
self.passwd=passwd
self.charset=charset
def connect(self):
self.conn=MySQLdb.connect(host=self.host,port=self.port,db=self.db,user=self.user,passwd=self.passwd,charset=self.charset)
self.cursor=self.conn.cursor()
def close(self):
self.cursor.close()
self.conn.close()
def get_one(self,sql,params=()):
result=None
try:
self.connect()
self.cursor.execute(sql, params)
result = self.cursor.fetchone()
self.close()
except Exception as e:
print(e)
return result
def get_all(self,sql,params=()):
list=()
try:
self.connect()
self.cursor.execute(sql,params)
list=self.cursor.fetchall()
self.close()
except Exception as e:
print(e)
return list
def insert(self,sql,params=()):
return self.__edit(sql,params)
def update(self, sql, params=()):
return self.__edit(sql, params)
def delete(self, sql, params=()):
return self.__edit(sql, params)
def __edit(self,sql,params):
count=0
try:
self.connect()
count=self.cursor.execute(sql,params)
self.conn.commit()
self.close()
except Exception as e:
print(e)
return count
添加
- 创建testInsertWrap.py文件，使用封装好的帮助类完成插入操作
from MysqlHelper import *
sql='insert into students(sname,gender) values(%s,%s)'
sname=raw_input("请输入用户名：")
gender=raw_input("请输入性别，1为男，0为女")
params=[sname,bool(gender)]
mysqlHelper=MysqlHelper('localhost',3306,'test1','root','mysql')
count=mysqlHelper.insert(sql,params)
if count==1:
print('ok')
else:
print('error')
查询一个
- 创建testGetOneWrap.py文件，使用封装好的帮助类完成查询最新一行数据操作
from MysqlHelper import *
sql='select sname,gender from students order by id desc'
helper=MysqlHelper('localhost',3306,'test1','root','mysql')
one=helper.get_one(sql)
print(one)
---
### 结束语
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