python-learning-第二季-数据库编程

https://www.bjsxt.com/down/8468.html

代码实现：

#coding:utf-

#导入模块

import sqlite3

#创建connect连接

con = sqlite3.connect('./sqlitedb/demo.db')

print(con) #查看连接是否成功生成,<sqlite3.Connection object at 0x10ae6b3b0>

#创建游标对象

cur = con.cursor()

#编写创建表的sql语句

sql = '''create table t_person(

        pno INTEGER primary key autoincrement,

        pname VARCHAR not null,

        age INTEGER

    )'''

try:

    #执行说sql语句

    cur.execute(sql)

    print('创建表成功')

except Exception as e:

    print(e)

finally:

    #关闭游标

    cur.close()

    #关闭连接

    con.close()

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

<sqlite3.Connection object at 0x106ded3b0>

创建表成功

操作sqlite3数据库插入数据

#coding:utf-

#导入模块

import sqlite3

#创建connect连接

con = sqlite3.connect('./sqlitedb/demo.db')

print(con) #查看连接是否成功生成,<sqlite3.Connection object at 0x10ae6b3b0>

#创建游标对象

cur = con.cursor()

#pno是自增长的，可不赋值

#（?,?）表示占位符，在执行时会传入

sql = 'insert into t_person(pname, age) values (?,?)'

try:

    #执行说sql语句

    cur.execute(sql, ('张三', ))

    #提交事务

    con.commit()

    print('插入成功')

except Exception as e:

    print(e)

    #回滚

    con.rollback()

    print('插入数据失败')

finally:

    #关闭游标

    cur.close()

    #关闭连接

    con.close()

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

<sqlite3.Connection object at 0x10c6ac3b0>

插入成功

Process finished with exit code

插入多条数据：

#coding:utf-

#导入模块

import sqlite3

#创建connect连接

con = sqlite3.connect('./sqlitedb/demo.db')

print(con) #查看连接是否成功生成,<sqlite3.Connection object at 0x10ae6b3b0>

#创建游标对象

cur = con.cursor()

#pno是自增长的，可不赋值

#（?,?）表示占位符，在执行时会传入

sql = 'insert into t_person(pname, age) values (?,?)'

try:

    #执行插入多条sql语句

    cur.executemany(sql, [('小李', ), ('小明', ), ('小雨', )])

    #提交事务

    con.commit()

    print('插入多条数据成功')

except Exception as e:

    print(e)

    #回滚

    con.rollback()

    print('插入多条数据失败')

finally:

    #关闭游标

    cur.close()

    #关闭连接

    con.close()

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

<sqlite3.Connection object at 0x1019fd3b0>

插入多条数据成功

Process finished with exit code

操作sqlite3数据库查询数据

#coding:utf-

#导入模块

import sqlite3

#创建connect连接

con = sqlite3.connect('./sqlitedb/demo.db')

print(con) #查看连接是否成功生成,<sqlite3.Connection object at 0x10ae6b3b0>

#创建游标对象

cur = con.cursor()

sql = 'select * from t_person'

try:

    #执行查询所有sql内容

    cur.execute(sql)

    #获取所有数据

    person_all = cur.fetchall()

    #返回的是数组

    #遍历输出

    for p in person_all:

        print(p)

except Exception as e:

    print(e)

    print('查询失败')

finally:

    #关闭游标

    cur.close()

    #关闭连接

    con.close()

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

<sqlite3.Connection object at 0x105f903b0>

(, '张三', )

(, '小李', )

(, '小明', )

(, '小雨', )

Process finished with exit code

查询一条：

#coding:utf-

#导入模块

import sqlite3

#创建connect连接

con = sqlite3.connect('./sqlitedb/demo.db')

print(con) #查看连接是否成功生成,<sqlite3.Connection object at 0x10ae6b3b0>

#创建游标对象

cur = con.cursor()

sql = 'select * from t_person'

try:

    #执行查询所有数据sql语句

    cur.execute(sql)

    #获取一条数据

    person = cur.fetchone()

    print(person)

except Exception as e:

    print(e)

    print('查询失败')

finally:

    #关闭游标

    cur.close()

    #关闭连接

    con.close()

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

<sqlite3.Connection object at 0x1092793b0>

(, '张三', )

Process finished with exit code

修改数据：

#coding:utf-

#导入模块

import sqlite3

#创建connect连接

con = sqlite3.connect('./sqlitedb/demo.db')

print(con) #查看连接是否成功生成,<sqlite3.Connection object at 0x10ae6b3b0>

#创建游标对象

cur = con.cursor()

sql = 'update t_person set pname=? where pno=?'

try:

    #执行修改sql语句

    cur.execute(sql,('张四',))

    #提交事务

    con.commit()

    print('修改成功')

except Exception as e:

    print(e)

    #回滚

    con.rollback()

    print('修改失败')

finally:

    #关闭游标

    cur.close()

    #关闭连接

    con.close()

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

<sqlite3.Connection object at 0x10d4bb3b0>

修改成功

Process finished with exit code

查询可见修改成功：

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

<sqlite3.Connection object at 0x10ab113b0>

(, '张四', )

Process finished with exit code

删除数据：

#coding:utf-

#导入模块

import sqlite3

#创建connect连接

con = sqlite3.connect('./sqlitedb/demo.db')

print(con) #查看连接是否成功生成,<sqlite3.Connection object at 0x10ae6b3b0>

#创建游标对象

cur = con.cursor()

sql = 'delete from t_person where pno=?'

try:

    #执行删除sql语句

    cur.execute(sql,(,)) #元组仅有一个参数，必需有面加逗号，保证参数类型为元组

    #提交事务

    con.commit()

    print('删除成功')

except Exception as e:

    print(e)

    #回滚

    con.rollback()

    print('删除失败')

finally:

    #关闭游标

    cur.close()

    #关闭连接

    con.close()

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

<sqlite3.Connection object at 0x101ebb3b0>

删除成功

Process finished with exit code

此时查看第一条数据为：

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

<sqlite3.Connection object at 0x101e623b0>

(, '小李', )

Process finished with exit code

MySQL数据库的下载

我已经安装好了，这里省略，去官网下载即可，端口默认3306

安装对应的模块PyMySQL

以为之前的deeplearning中的可用在这，发现不行，所以就重新下载了：

(venv) (base) userdeMBP:python3 user$ pip install PyMySQL

Collecting PyMySQL

  Using cached https://files.pythonhosted.org/packages/ed/39/15045ae46f2a123019aa968dfcba0396c161c20f855f11dea6796bcaae95/PyMySQL-0.9.3-py2.py3-none-any.whl

Installing collected packages: PyMySQL

Successfully installed PyMySQL-0.9.

我已经下载好了

操作MySQL数据库创建表

先是创建了数据库python_db:

首先先连接：

#导入pymysql

import pymysql

#创建连接

con = pymysql.connect(host='localhost', user='root', password='user78', database='python_db', port=)

print(con)

成功连接：

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

<pymysql.connections.Connection object at 0x103d3f6a0>

Process finished with exit code

#导入pymysql

import pymysql

#创建连接

con = pymysql.connect(host='localhost', user='root', password='user78', database='python_db', port=)

#创建游标对象

cur = con.cursor()

#编写创建表的sql，score总共三位，小数点占一位

sql = '''

    create table t_student(

        sno int primary key auto_increment,

        sname varchar() not null,

        age int(),

        score float(,)

    )

'''

try:

    #执行创建表的sql

    cur.execute(sql)

    print('创建成功')

except Exception as e:

    print(e)

    print('创建失败')

finally:

    #关闭游标

    cur.close()

    #关闭连接

    con.close()

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

创建成功

Process finished with exit code

查看成功创建：

插入数据：

#导入pymysql

import pymysql

#创建连接

con = pymysql.connect(host='localhost', user='root', password='user78', database='python_db', port=)

#创建游标对象

cur = con.cursor()

#插入数据

sql = 'insert into t_student(sname, age, score) values(%s, %s, %s)'

try:

    #执行创建表的sql

    cur.execute(sql, ('王一', , ))

    #提交事务

    con.commit()

    print('插入成功')

except Exception as e:

    print(e)

    con.rollback()

    print('插入失败')

finally:

    #关闭游标

    cur.close()

    #关闭连接

    con.close()

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

插入成功

Process finished with exit code

查看：

插入多条数据：

#导入pymysql

import pymysql

#创建连接

con = pymysql.connect(host='localhost', user='root', password='user78', database='python_db', port=)

#创建游标对象

cur = con.cursor()

#插入数据

sql = 'insert into t_student(sname, age, score) values(%s, %s, %s)'

temp = [('王二', , ), ('王三', , )]

try:

    #执行创建表的sql

    cur.executemany(sql, temp)

    #提交事务

    con.commit()

    print('插入成功')

except Exception as e:

    print(e)

    con.rollback()

    print('插入失败')

finally:

    #关闭游标

    cur.close()

    #关闭连接

    con.close()

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

插入成功

Process finished with exit code

查看：

查询数据

#导入pymysql

import pymysql

#创建连接

con = pymysql.connect(host='localhost', user='root', password='user78', database='python_db', port=)

#创建游标对象

cur = con.cursor()

#查询多个数据

sql = 'select * from t_student where age >= 19'

try:

    #执行创建表的sql

    cur.execute(sql)

    students = cur.fetchall()

    print(students)

    print('查询成功')

except Exception as e:

    print(e)

    print('查询失败')

finally:

    #关闭游标

    cur.close()

    #关闭连接

    con.close()

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

((, '王二', , 70.0), (, '王三', , 80.0))

查询成功

Process finished with exit code

查询：

#导入pymysql

import pymysql

#创建连接

con = pymysql.connect(host='localhost', user='root', password='user78', database='python_db', port=)

#创建游标对象

cur = con.cursor()

#查询多个数据

sql = 'select * from t_student where age >= 19'

try:

    #执行创建表的sql

    cur.execute(sql)

    students = cur.fetchall()

    for student in students:

        print(student[], end = ' ,')

        print(student[], end=' ,')

        print(student[], end=' ,')

        print(student[])

except Exception as e:

    print(e)

    print('查询失败')

finally:

    #关闭游标

    cur.close()

    #关闭连接

    con.close()

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

 ,王二 , ,70.0

 ,王三 , ,80.0

Process finished with exit code

查询一个数据：

#导入pymysql

import pymysql

#创建连接

con = pymysql.connect(host='localhost', user='root', password='user78', database='python_db', port=)

#创建游标对象

cur = con.cursor()

#查询一个数据

sql = 'select * from t_student where age >= 19'

try:

    #执行创建表的sql

    cur.execute(sql)

    student = cur.fetchone()

    print(student)

except Exception as e:

    print(e)

    print('查询失败')

finally:

    #关闭游标

    cur.close()

    #关闭连接

    con.close()

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

(, '王二', , 70.0)

Process finished with exit code

更新数据：

#导入pymysql

import pymysql

#创建连接

con = pymysql.connect(host='localhost', user='root', password='user78', database='python_db', port=3306)

#创建游标对象

cur = con.cursor()

#查询一个数据

sql = 'update t_student set sname=%s where sno =%s'

try:

    #执行创建表的sql

    cur.execute(sql, ('王五', 1))

    #提交事务

    con.commit()

    print('更新成功')

except Exception as e:

    print(e)

    con.rollback()

    print('更新失败')

finally:

    #关闭游标

    cur.close()

    #关闭连接

    con.close()

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

更新成功

Process finished with exit code 0

查看：

删除数据：

#导入pymysql

import pymysql

#创建连接

con = pymysql.connect(host='localhost', user='root', password='user78', database='python_db', port=3306)

#创建游标对象

cur = con.cursor()

#查询一个数据

sql = 'delete from t_student  where sname =%s'

try:

    #执行创建表的sql

    cur.execute(sql, ('王五',))

    #提交事务

    con.commit()

    print('删除成功')

except Exception as e:

    print(e)

    con.rollback()

    print('删除失败')

finally:

    #关闭游标

    cur.close()

    #关闭连接

    con.close()

/Users/user/PycharmProjects/python3/venv/bin/python /Users/user/PycharmProjects/python3/test.py

更新成功

Process finished with exit code 0

查看：

python-learning-第二季-数据库编程的更多相关文章

python下的MySQL数据库编程
https://www.tutorialspoint.com/python/python_database_access.htm if you need to access an Oracle dat ...
python 教程第二十章、数据库编程
第二十章. 数据库编程环境设置 1).安装MySQL-python http://www.lfd.uci.edu/~gohlke/pythonlibs/ MySQL-python-1.2.3.win ...
小课堂week17 编程范式巡礼第二季并发那些事
编程范式巡礼第二季并发那些事继续上周的编程范式话题,今天想聊一下并发范式. 并发也算一种范式? 真正的并发式编程,绝不只是调用线程API或使用synchronized.lock之类的关键字那么简单 ...
运用Python语言编写获取Linux基本系统信息(三)：Python与数据库编程，把获取的信息存入数据库
运用Python语言编写获取Linux基本系统信息(三):Python与数据库编程有关前两篇的链接: 运用Python语言编写获取Linux基本系统信息(一):获得Linux版本.内核.当前时间运 ...
Python学习系列（七）( 数据库编程）
Python学习系列(七)( 数据库编程) Python学习系列(六)(模块) 一,MySQL-Python插件 Python里操作MySQL数据库,需要Python下安装访 ...
Python程序设计9——数据库编程
1 数据持久化持久化是将内存中的对象存储在关系数据库中,当然也可以存储在磁盘文件.XML数据文件中.实现数据持久化至少需要实现以下3个接口 void Save(object o):把一个对象保存到外 ...
python 闯关之路四（下）（并发编程与数据库编程）并发编程重点
python 闯关之路四(下)(并发编程与数据库编程) 并发编程重点: 1 2 3 4 5 6 7 并发编程:线程.进程.队列.IO多路模型操作系统工作原理介绍.线程.进程演化史.特点.区别 ...
python之数据库编程
python之数据库编程 sqlite 1.前期准备工作导入模块: import sqlite3 连接数据库 conn = sqlite3.connect("test.db") ...
python数据库编程_sqlite
原文请看:http://blog.csdn.net/jj_liuxin/article/details/3584448 sqlite是一个轻量级的数据库,与很多大型的数据库(例如DB2,Oracle, ...

随机推荐

K-D树详解
K-D树最近邻算法https://blog.csdn.net/image_fzx/article/details/80624968 一般说来,索引结构中相似性查询有两种基本的方式: 一种是范围查询,范 ...
linux系统编程之进程(三)
今天继续学习进程相关的东东,继上节最后简单介绍了用exec函数替换进程映像的用法,今天将来深入学习exec及它关联的函数,话不多说,正式进入正题: exec替换进程映象: 对于fork()函数,它 ...
The server time zone value '�й��׼ʱ��' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use
java.sql.SQLException: The server time zone value '�й��׼ʱ��' is unrecognized or represents more tha ...
vue-cli 3 按需引入 element-ui
1.安装按需引入必要插件 npm install babel-plugin-component --save-dev 2.修改babel.config.js 3.在main.js中引入用到的组件,例如 ...
vscode——设置自动保存
前言懒就一个字步骤打开设置第一项就是,选择焦点改变自动保存即可
关于Spring的常用注解和接口
接口 1. BeanPostProcessor 2. FactoryBean 3. Condition 4. ImportSelector 5. ImportBeanDefinitionRegitra ...
php获取时期时间信息函数
在正式学习日期函数前大家得了解几个概念: 1.时区 2.世界时 3.unix时间戳时区这个概念,之前大家听说过很多.我们来啰嗦两句,我们现实生活中使用的实区,在电脑里面也是一样有规定的.大理石机械 ...
IDEA设置提示生成序列化ID
背景: 实现Serializable接口的类,没有提示生成序列化ID 解决问题: 1.FIle->Settings->Editor->inspections 2.点击java-> ...
[C++11]C++可变参数模板
可变参数模板原文链接: http://blog.csdn.net/xiaohu2022/article/details/69076281 普通模板只可以采取固定数量的模板参数.然而,有时候我们希望模 ...
C# 线程小结
进程与线程什么是进程? 当一个程序开始运行时,它就是一个进程,进程包括运行中的程序和程序所使用到的内存和系统资源. 而一个进程又是由多个线程所组成的. 什么是线程? 线程是程序中的一个执行流,每个线 ...

python-learning-第二季-数据库编程

python-learning-第二季-数据库编程的更多相关文章

随机推荐

热门专题