Question

我正在使用vue js进行前端开发，并且我使用loopback api进行后端。当我制作请求表单回送api时，它工作正常，但是当我尝试从网页插入数据时，控制台窗口出现以下错误。

HTMLPage2.html：101 POST http://localhost:3000/api/Cat/ 422（不可处理实体）

这是我的代码。

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title></title>
  <meta name="description" content="">
  <meta name="viewport" content="width=device-width">

  <script src="./server.js"></script>
  <script src="https://cdn.jsdelivr.net/npm/vue"></script>
  <script src="https://cdn.jsdelivr.net/npm/vue@2.6.10/dist/vue.js"></script>





</head>
<body>

  <div id="catApp">

    <h1>Cats</h1>
    <table>
      <thead>
        <tr>
          <th>Name</th>
          <th>Age</th>
          <th>Gender</th>
          <th>Breed</th>
          <td>&nbsp;</td>
        </tr>
      </thead>
      <tbody>
        <tr v-for="cat in cats">
          <td @click="editCat(cat)" class="catItem" title="Click to Edit">{{cat.name}}</td>
          <td>{{cat.age}}</td>
          <td>{{cat.gender}}</td>
          <td>{{cat.breed}}</td>
          <td @click="deleteCat(cat)" class="deleteCat" title="Click to Delete">Delete</td>
        </tr>
      </tbody>
    </table>

    <form @submit.prevent="storeCat">
      <p>
        <label for="name">Name</label>
        <input type="text" id="name" v-model="cat.name">
      </p>
      <p>
        <label for="age">Age</label>
        <input type="number" id="age" v-model="cat.age">
      </p>
      <p>
        <label for="breed">Breed</label>
        <input type="text" id="breed" v-model="cat.breed">
      </p>
      <p>
        <label for="gender">Gender</label>
        <input type="text" id="gender" v-model="cat.gender">
      </p>
      <input type="reset" value="Clear" @click="reset">
      <input type="submit" value="Save Cat ?">
    </form>
  </div>

  <script>
    const API = 'http://localhost:3000/api/Cat/';
    let catApp = new Vue({
      el: '#catApp',
      data: {
        cats: [],
        cat: {
          id: '',
          name: '',
          age: '',
          gender: '',
          breed: ''
        }
      },
      created: function () {
        this.getCats();
      },
      methods: {
        getCats: function () {
          fetch(API)
            .then(res => res.json())
            .then(res => this.cats = res);
        },
        storeCat: function () {
          let method;
          console.log('storeCat', this.cat);
          // Handle new vs old
          if (this.cat.id === '') {
            delete this.cat.id;
            method = 'POST';
          } else {
            method = 'PUT';
          }
          fetch(API, {
            headers: {
              'Content-Type': 'application/json'
            },
            method: method,
            body: JSON.stringify(this.cat)
          })
            .then(res => res.json())
            .then(res => {
              this.getCats();
              this.reset();
            });
        },
        deleteCat: function (c) {
          fetch(API + c.id, {
            headers: {
              'Content-Type': 'application/json'
            },
            method: 'DELETE'
          })
            .then(res => res.json())
            .then(res => {
              this.getCats();
            });

          // call reset cuz the cat could be 'active'
          this.reset();
        },
        editCat: function (c) {
          /*
          This line was bad as it made a reference, and as you typed, it updated
          the list. A user may think they don't need to click save.
          this.cat = c;
          */
          this.cat.id = c.id;
          this.cat.name = c.name;
          this.cat.age = c.age;
          this.cat.breed = c.breed;
          this.cat.gender = c.gender;
        },
        reset: function () {
          this.cat.id = '';
          this.cat.name = '';
          this.cat.age = '';
          this.cat.breed = '';
          this.cat.gender = '';
        }
      }
    });
  </script>
</body>
</html>

这是错误的屏幕截图。

Answer 1

请执行以下步骤：

1）只需将您的API端点更新为“ http://localhost:3000/api/Cats/”。

2）刷新您的html文件。

Answer 2

422（不可处理实体）表示您对数据请求进行验证并且失败，或者您尝试将数据直接插入数据库中，但是发生错误，原因是数据为null，并且您的列不允许为null或其他。.

确保您的数据正确无误如果您单击控制台中的最后一个链接（如图所示），您将在网络数据中看到请求的响应

环回引发错误无法处理的实体

2 个答案: