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  • pymysql模块及mysql备份

    pymysql模块及mysql备份

    #配置
    conn = pymysql.connect(host='127.0.0.1',
                           user='root',
                           password="123",
                           database='homework')
    #cur = conn.cursor(cursor=pymysql.cursors.DictCursor)  # 查询返回字典
    cur = conn.cursor()  # cursor游标
    cur.execute('select * from student;')
    print(cur.rowcount)   # 获取查出多少行,便于使用fetchone取所有结果
    for i in range(cur.rowcount):
        ret = cur.fetchone()      # 获取一条结果
        print(ret)
    
    try:
        cur.execute('select * from student;')
        ret = cur.fetchone()      # 获取一条结果
        print(ret)
        ret2 = cur.fetchmany(10)  # 获取多条结果
        print(ret2)
        ret3 = cur.fetchall()     # 获取全部结果
        print(ret3)
    except pymysql.err.ProgrammingError as e:
        print(e)
    cur.close()
    conn.close()
    
    # 增加 删除 修改
    conn = pymysql.connect(host='127.0.0.1',
                           user='root',
                           password="123",
                           database='homework')
    cur = conn.cursor()  # cursor游标
    try:
        # cur.execute('insert into student values(18,"男",3,"大壮")')
        # cur.execute('update student set gender = "女" where sid = 17')
        cur.execute('delete from student where sid = 17')
        conn.commit()
    except Exception as e:
        print(e)
        conn.rollback()     # 可以试一下 myisam
    cur.close()
    conn.close()
    
    # 结合数据库 和python 写一个登录
    user = input('username :')
    pwd = input('password :')
    conn = pymysql.connect(host='127.0.0.1',
                           user='root',
                           password="123",
                           database='day42')
    sql = 'select * from userinfo where user = %s and password = %s'
    cur = conn.cursor()
    cur.execute(sql,(user,pwd))
    print(cur.fetchone())
    # sql注入
    # select * from userinfo where user = "1869" or 1=1;-- " and password = "3714";
    #用户名任意 后面密码失效
    
    表和数据的备份
        备份数据 在cmd命令行直接执行
        mysqldump -uroot -p123 -h127.0.0.1 homework > D:python_22day42	mp.sql
    
        恢复数据 在mysql中执行命令
        切换到一个要备份的数据库中
        source D:python_22day42	mp.sql
    
    备份库
        备份
        mysqldump -uroot -p123 --databases homework > D:python_22day42	mp2.sql
        恢复
        source D:python_22day42	mp2.sql
    
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  • 原文地址:https://www.cnblogs.com/wyh0717/p/13429793.html
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