sequelize.js - Sequelize : Column not found immediately after creation

Question

在同一个发布 route ，我试图创建一个新类(class)，然后通过 findAll() 方法选择该类(class)。我这样做是因为我想将位置 header 设置为 jsut 创建的类(class)的正确 URI。为此，我需要访问其自动生成的 ID。问题是，当我调用 findAll() 方法时，它说找不到我刚刚创建的类(class)。

app.post('/api/courses', async (req, res) => {
    try {

        const newCourse = req.body;


        await Course.create({
            title: newCourse.title,
            description: newCourse.description,
            estimatedTime: newCourse.estimatedTime,
            materialsNeeded: newCourse.materialsNeeded,
            userId: 1

        })
        const course = await Course.findAll({
            attributes: [newCourse.title]
        })


        res.location('/api/courses/' + course.id)
        res.status(201); 
    }catch(error) {
        console.warn(error);
    }

})

app.get('/api/courses/:id', async (req, res) => {
    try {
        const courseRequest = req.params.id;

        const course = await Course.findAll({
            where: {
                id: courseRequest
            },
            attributes: ['title', 'userId']
        })

         res.json({
            course
        }); 
    }catch(error) {
        console.error(error);
    }

})

Naor Levi 发表评论后更新
我将新创建的类(class)记录到控制台，它返回以下内容:

Course {
  dataValues:
   { id: 11,
     title: 'Investing for beginners',
     description: 'Learn to invest your money wisely',
     estimatedTime: '3 weeks',
     materialsNeeded: 'pen and paper',
     userId: 1,
     updatedAt: 2020-01-13T23:50:53.748Z,
     createdAt: 2020-01-13T23:50:53.748Z },
  _previousDataValues:
   { title: 'Investing for beginners',
     description: 'Learn to invest your money wisely',
     estimatedTime: '3 weeks',
     materialsNeeded: 'pen and paper',
     userId: 1,
     id: 11,
     createdAt: 2020-01-13T23:50:53.748Z,
     updatedAt: 2020-01-13T23:50:53.748Z },
  _changed:
   { title: false,
     description: false,
     estimatedTime: false,
     materialsNeeded: false,
     userId: false,
     id: false,
     createdAt: false,
     updatedAt: false },
  _modelOptions:
   { timestamps: true,
     validate: {},
     freezeTableName: false,
     underscored: false,
     paranoid: false,
     rejectOnEmpty: false,
     whereCollection: null,
     schema: null,
     schemaDelimiter: '',
     defaultScope: {},
     scopes: {},
     indexes: [],
     name: { plural: 'Courses', singular: 'Course' },
     omitNull: false,
     sequelize:
      Sequelize {
        options: [Object],
        config: [Object],
        dialect: [SqliteDialect],
        queryInterface: [QueryInterface],
        models: [Object],
        modelManager: [ModelManager],
        connectionManager: [ConnectionManager],
        importCache: [Object] },
     hooks: {} },
  _options:
   { isNewRecord: true,
     _schema: null,
     _schemaDelimiter: '',
     attributes: undefined,
     include: undefined,
     raw: undefined,
     silent: undefined },
  isNewRecord: false }
Executing (default): SELECT `Investing for beginners` FROM `Courses` AS `Course`;
{ SequelizeDatabaseError: SQLITE_ERROR: no such column: Investing for beginners

它告诉我我刚刚创建的类(class)不存在，我不知道为什么。

Answer 1

您可以在 dataValues 下看到刚刚创建了一个带有 id: 11 的新行。

您的问题是 findAll 的 Sequelize.Model 返回一个模型实例数组，而您尝试访问单个实例。
此外，您只要求提供 title 属性，然后您尝试访问 course.id。即，即使您正确访问了 findAll 的返回值，也不会在结果中找到 id 属性。

尝试根据以下示例修复您的代码:

app.post('/api/courses', async (req, res) => {
    try {
        const newCourse = req.body;
        let course = await Course.create({
            title: newCourse.title,
            description: newCourse.description,
            estimatedTime: newCourse.estimatedTime,
            materialsNeeded: newCourse.materialsNeeded,
            userId: 1
        });

        // This is redundant and wrong.
        // const course = await Course.findAll({
        //    attributes: [newCourse.title]
        // })

        const courseParam = course.dataValues.id;
        res.location(`/api/courses/${courseParam}`);
        res.status(201); 
    }catch(error) {
        console.warn(error);
    }

});