python操作三大主流数据库(2)python操作mysql②python对mysql进行简单的增删改查

python操作mysql②python对mysql进行简单的增删改查

1.设计mysql的数据库和表

id:新闻的唯一标示
title:新闻的标题
content:新闻的内容
created_at:新闻添加的时间
types:新闻的类型
image:新的缩略图
author:作者
view_count:浏览量
is_valid:删除标记

# 创建新闻数据库
create database news charset=utf8;

# 创建新闻表
create table news(
    id int primary key auto_increment,
    title varchar(200) not null,
    content varchar(2000) not null,
    types varchar(10) not null,
    image varchar(300) null,
    author varchar(20) null,
    view_count int default 0,
    created_at datetime null,
    is_valid smallint default 1
) default charset="utf8";
'''

插入数据
INSERT INTO `news` VALUES ('1', '朝鲜特种部队视频公布 展示士兵身体素质与意志', '新闻内容', '推荐', '/static/img/news/01.png', null, '0', null, '1');
INSERT INTO `news` VALUES ('2', '男子长得像"祁同伟"挨打 打人者:为何加害检察官', '新闻内容', '百家', '/static/img/news/02.png', null, '0', null, '1');
INSERT INTO `news` VALUES ('3', '导弹来袭怎么办？日本政府呼吁国民堕入地下通道', '新闻内容', '本地', '/static/img/news/03.png', null, '0', null, '1');
INSERT INTO `news` VALUES ('4', '美监:朝在建能发射3发以上导弹的3000吨级新潜艇', '新闻内容', '推荐', '/static/img/news/04.png', null, '0', null, '1');
INSERT INTO `news` VALUES ('5', '证监会：前发审委员冯小树违法买卖股票被罚4.99亿', '新闻内容', '百家', '/static/img/news/08.png', null, '0', null, '1');
INSERT INTO `news` VALUES ('6', '外交部回应安倍参拜靖国神社:同军国主义划清界限', '新闻内容', '推荐', '/static/img/news/new1.jpg', null, '0', null, '1');
INSERT INTO `news` VALUES ('7', '"萨德"供地违法？韩民众联名起诉要求撤回供地', '新闻内容', '百家', '/static/img/news/new2.jpg', null, '0', null, '1');
INSERT INTO `news` VALUES ('10', '标题1', '新闻内容1', '推荐', '/static/img/news/01.png', null, '0', null, '1');


2.python简单操作mysql之数据库的连接和简单获取数据
#encoding:utf-8

import MySQLdb

'''
# 简单的连接
# 获取连接
conn = MySQLdb.connect(
    host = '127.0.0.1',
    user = 'root',
    password = '',
    db = 'news',
    port = 3306,
    charset = 'utf8'
)

# 获取数据
cursor = conn.cursor()
cursor.execute('select * from news order by created_at desc')
rest = cursor.fetchone()
print(rest)

# 关闭连接
conn.close()

3.python简单操作mysql之数据库的连接和简单获取数据改进之捕获异常

# 捕获异常
# 获取连接
try:
    conn = MySQLdb.connect(
        host = '127.0.0.1x',
        user = 'root',
        password = '',
        db = 'news',
        port = 3306,
        charset = 'utf8'
    )

    # 获取数据
    cursor = conn.cursor()
    cursor.execute('select * from news order by created_at desc')
    rest = cursor.fetchone()
    print(rest)

    # 关闭连接
    conn.close()
except MySQLdb.Error as e:
    print('mysql error:%s' % e)


4.python简单操作mysql之数据库的连接和单获取所有数据
# 获取连接
try:
    conn = MySQLdb.connect(
        host = '127.0.0.1',
        user = 'root',
        password = '',
        db = 'news',
        port = 3306,
        charset = 'utf8'
    )

    # 获取数据
    cursor = conn.cursor()
    cursor.execute('select * from news')
    rows = cursor.fetchall()
    print(cursor.description)

    for row in rows:
        print(row)

    # 关闭连接
    conn.close()
except MySQLdb.Error as e:
    print('mysql error:%s' % e)


5.python简单操作mysql之数据库的操作类

class MysqlConnection(object):

    # 初始化
    def __init__(self, host = '127.0.0.1', port = 3306, user = 'root', password = '', db = 'news',charset='utf8'):
        self._host = host
        self._port = port
        self._user = user
        self._password = password
        self._db = db
        self._charset = charset
        self._conn = None
        self._cursor = None
        self.get_conn()

    # 关闭数据库连接
    def close(self):
        if self._cursor:
            self._cursor.close()
            self._cursor = None

        if self._conn:
            self._conn.close()
            self._conn = None

    def commit(self):
        self._conn.commit()

    # 获取数据库连接
    def get_conn(self):
        try:
            self._conn = MySQLdb.connect(
                host = self._host,
                user = self._user,
                password = self._password,
                db = self._db,
                port = self._port,
                charset = self._charset
            )

            self._cursor = self._conn.cursor()
        except MySQLdb.Error as e:
            print('mysql error:%s' % e)


    # 获取单条新闻
    def get_one(self):

        sql = 'select * from news where types = %s order by created_at desc'
        # 获取数据
        self._cursor.execute(sql,('百家',))
        rest = dict(zip([k[0] for k in self._cursor.description], self._cursor.fetchone()))

        # 关闭连接
        self.close()
        return rest

    # 获取多条新闻
    def get_more(self):

        sql = 'select * from news where types = %s order by created_at desc'
        # 获取数据
        self._cursor.execute(sql,('百家',))
        rest = [dict(zip([k[0] for k in self._cursor.description], row)) 
        for row in self._cursor.fetchall()]

        # 关闭连接
        self.close()
        return rest

    def add_one(self):
        sql = 'insert into news(title,image,content,types,is_valid) values(%s, %s, %s, %s, %s)'
        self._cursor.execute(sql, ('标题1','/static/img/news/01.png', '新闻内容1','推荐',1))
        self.commit()
        self.close()

def main():
    obj = MysqlConnection()
    # rst = obj.get_more()
    # rst = obj.get_one()
    # print(rst)
    obj.add_one()

if __name__ == "__main__":
    main()