python基础学习-python操作sqlite数据库

'''

python使用sqlite数据库

'''

import sqlite3

con = sqlite3.connect("./test.db")#在磁盘上创建数据库

# con = sqlite3.connect(":memory:")#在内存中创建数据库

cu=con.cursor()#创建一个游标

returnCu = cu.execute("select count(*) from sqlite_master where type='table' and name='user'")

returnTuple = returnCu.fetchone()

#如果表存在则删除表

if returnTuple[0]==1:
cu.execute("drop table user")

#创建表

cu.execute("create table user(id integer primary key,username varchar(20),password varchar(20))")

#插入数据

cu.execute("insert into user values(?,?,?)",(1,"xiaobing","123"))

cu.execute("insert into user values(?,?,?)",(2,"xiaoming","123"))

con.commit()#提交

#查询表数据

returnCu = cu.execute("select * from user")

for (userid,username,password) in returnCu:
print userid,username,password

#修改数据

cu.execute("update user set password=? where id=?",("123456",1))

con.commit()

returnCu = cu.execute("select * from user where id=?",(1,))

getUserCu = returnCu.fetchone()

print getUserCu[2]

#删除数据

cu.execute("delete from user where id=?",(2,))

con.commit()

returnCu = cu.execute("select * from user")

for (userid,username,password) in returnCu:
print userid,username,password

con.close()