PYTHON第六十九天笔记11.30星期四

一、课上笔记

day69

今日内容：
    老师信息（任教班级）的增删改查
        
        
    模板语言for循环：
    {% for teacher in  teacher_list %}
        要做的事儿
    {% empty %}
        要做的事儿
    {% endfor %}
    
    
    查询老师表和teacher2class
    select teacher.id, teacher.name, teacher2class.class_id from teacher LEFT JOIN teacher2class ON teacher.id = teacher2class.teacher_id;
    查询老师表和teacher2class和class表（你们有更好的方法）
    select teacher.id, teacher.name, class.name from teacher LEFT JOIN teacher2class ON teacher.id = teacher2class.teacher_id LEFT JOIN class ON teacher2class.class_id = class.id;
    
    
    select t2.td ,t2.tn,group_concat(class.name) as cn ,group_concat(class.id) as cd from class INNER join
    (select t1.id as td,t1.name as tn,class_id  from teacher2class inner join
    (select teacher.id,teacher.name from teacher)t1 ON teacher2class.teacher_id=t1.id)t2 on t2.class_id=class.id GROUP by t2.td

    
    [
        {'id': 1, 'name': 'Alex', 'cname': '全栈99999期'},
        {'id': 2, 'name': 'Egon', 'cname': '全栈99999期'},
        {'id': 3, 'name': 'Yuan', 'cname': '全栈99999期'},
        {'id': 1, 'name': 'Alex', 'cname': '全栈9期'},
        {'id': 1, 'name': 'Alex', 'cname': '全栈10期'},
        {'id': 3, 'name': 'Yuan', 'cname': '全栈10期'}
    ]
    
    [
        
    ]
    
    request.POST.get()  --> 只能取一个值
    当前端（多选的select）提交的时候，用request.POST.get()不行
    request.POST.getlist()   --> 用这个可以取到一个列表
    
    
    取到刚插入的那条数据的ID：
        -ret = cursor.lastrowid  # 取到刚才创建的记录的ID
        
    AJAX发送数据：
        data：{“name”: "alex", "habit": ["抽烟", "喝酒“, "烫头"]}  这样不行
        data：{“name”: "alex", "habit": JSON.stringify(["抽烟", "喝酒“, "烫头"])} 这样可以
    

二、课堂图片

1

2

 3 知识点

 4 知识点