小编wgf*_*242的帖子

我的数据是这样的，我想序列化它们而不为它们创建模型。

[
  {'form': 1, 'count': 1},
  {'form': 2, 'count': 3}
]

序列化到

[
  {'form': 'my form name 1', 'count': 1},
  {'form': 'my form name 2', 'count': 3}
]

我想用序列化器序列化它，通过 pk 获取表单名称表单模型。

[
  {'form': 1, 'count': 1},
  {'form': 2, 'count': 3}
]

一些错误，例如'int' object has no attribute 'pk'

在python控件中测试

[
  {'form': 'my form name 1', 'count': 1},
  {'form': 'my form name 2', 'count': 3}
]

模型.py

class Form(models.Model):
    no = models.IntegerField()
    finish_date = models.DateField(blank=True, null=True)

序列化程序.py

class FormSerializer(serializers.ModelSerializer):
    class Meta:
        model = Form
        fields = '__all__'

如果我尝试：

http http://127.0.0.1:8000/api/forms no=112 "finish_date"=""

它返回错误：

"finish_date": [
    "Date has wrong format. Use one of these formats instead: YYYY[-MM[-DD]]."
]

如果我将 "finish_date" 设置为 null ，则这篇文章有效。并且StringField(blank=True, null=True)不会得到错误。

怎么解决？

http://127.0.0.1:8000/app_restFramework/users/,返回文字

/ app_restFramework/users /'User'对象的AttributeError没有属性'books'

models.py

class User(models.Model):
    username = models.CharField(max_length=100)

class Book(models.Model):
    name = models.CharField(max_length=100)
    author = models.CharField(max_length=100)
    publisher = models.CharField(max_length=100)
    time = models.CharField(max_length=100)
    owner = models.ManyToManyField(User)

serializers.py

from app_restFramework.models import Book,User
class UserSerializer(serializers.ModelSerializer):
    books = serializers.PrimaryKeyRelatedField(many = True, read_only = True)

    class Meta:
        model = User
        fields = ('id', 'username', 'books')

views.py

class UserList(generics.ListCreateAPIView):
    queryset = User.objects.all()
    serializer_class = UserSerializer

urls.py

url(r'^app_restFramework/users/$', app_restFramework.views.UserList.as_view() ), 

月-detail.component.html

import ...
@Component({
  template: `{{month?.id}} <app-month-date [month]="month"></app-month-date>`
})
export class MonthDetailComponent implements OnInit {
  month: Month;
  ngOnInit(): void {
    this.route.params
      .switchMap((params: Params) => this.monthService.getMonth(+params["id"]))
      .subscribe(month => (this.month = month));
  }
}

月-日.component.html

<p>month-date works! {{month?.id}}</p>

月-日.component.ts

import { Component, OnInit, Input } from "@angular/core";
import { Month } from "app/attendance/month";

@Component({
  selector: "app-month-date",
  ...
})
export class MonthDateComponent implements OnInit {
  @Input() month: Month;
  ngOnInit() {
    //undefined --- here
    console.log(this.month);
  }}

month?.id 在 中正确显示month-detail.component.html，但app-month-date在 中带有标记的月份未定义 …

我尝试用接口解构赋值，但不能这样写。

interface TYPE {
  id?: number;
  type?: string;
}

const e =  {
  'id': 123,
  'type': 'type_x',
  'other': 'other_x'
}
const {...foo}: {foo: TYPE} = e;
console.log(foo.id, foo.type) // expected: 123, 'type_x'

[a,b] = [b, a+b] 在这里不起作用，ab始终为0和1。

如果使用临时变量交换值，则可以。

function fibonacciSequence() {
  let [a, b, arr] = [0, 1, []]
  while (a <= 255) {
    arr.concat(a)
    [a, b] = [b, a + b]
    console.log(a, b) // always 0 1
  }
}
console.log(fibonacciSequence())