javascript - 从 postgres 获得对 sequelize findall 的空响应

问题描述

我是 node js 环境的新手，目前我正在练习一个 crud 应用程序我正在使用 sequelize 作为 ORM 并且我使用了 mvc 结构

npm install --save sequelize
$ npm install --save pg pg-hstore

我正在使用续集 cli

npm install --save-dev sequelize-cli

npx sequelize-cli init

这是我的迁移

'use strict';
module.exports = {
  up: async (queryInterface, Sequelize) => {
    await queryInterface.createTable('Books', {
      id: {
        allowNull: false,
        autoIncrement: true,
        primaryKey: true,
        type: Sequelize.INTEGER
      },
      firstName: {
        type: Sequelize.STRING
      },
      lastName: {
        type: Sequelize.STRING
      },
      email: {
        type: Sequelize.STRING
      },
      createdAt: {
        allowNull: false,
        type: Sequelize.DATE
      },
      updatedAt: {
        allowNull: false,
        type: Sequelize.DATE
      }
    });
  },
  down: async (queryInterface, Sequelize) => {
    await queryInterface.dropTable('Books');
  }
};

我的模型：

'use strict';
const {
  Model
} = require('sequelize');
module.exports = (sequelize, DataTypes) => {
  class Books extends Model {
    /**
     * Helper method for defining associations.
     * This method is not a part of Sequelize lifecycle.
     * The `models/index` file will call this method automatically.
     */
    static associate(models) {
      // define association here
    }
  };
  Books.init({
    firstName: DataTypes.STRING,
    lastName: DataTypes.STRING,
    email: DataTypes.STRING
  }, {
    sequelize,
    modelName: 'Books',
  });
  return Books;
};

我的控制器：

exports.allBooks = (req,res)=>{
const bookme = Books(**how to pass sequelize**,**how to pass sequelize datatype**)
    var booksJSON = bookme.findAll()
res.json(booksJSON)
console.log(JSON.stringify(booksJSON))
}

如果我通过手动创建与数据库的连接并使用 sequelize 将续集传递给书籍模型来自定义传递数据类型，我会得到空响应我认为我的错误在于传递这些参数。我应该将什么以及如何传递给 Books 模型

我在我的控制器中导入书籍模型如下：

const Books = require('../models/books.js');

同样，当我运行创建迁移、模型、种子文件夹的引导时，它还在模型文件夹中创建了一个 index.js 文件，我也尝试在参数中将它传递给 Books 模型，但它给出了错误

由 sequelize cli 包本身创建的模型文件夹中的 index.js

'use strict';

const fs = require('fs');
const path = require('path');
const Sequelize = require('sequelize');
const basename = path.basename(__filename);
const env = process.env.NODE_ENV || 'development';
const config = require(__dirname + '/../config/config.json')[env];
const db = {};

let sequelize;
if (config.use_env_variable) {
  sequelize = new Sequelize(process.env[config.use_env_variable], config);
} else {
  sequelize = new Sequelize(config.database, config.username, config.password, config);
}

fs
  .readdirSync(__dirname)
  .filter(file => {
    return (file.indexOf('.') !== 0) && (file !== basename) && (file.slice(-3) === '.js');
  })
  .forEach(file => {
    const model = require(path.join(__dirname, file))(sequelize, Sequelize.DataTypes);
    db[model.name] = model;
  });

Object.keys(db).forEach(modelName => {
  if (db[modelName].associate) {
    db[modelName].associate(db);
  }
});

db.sequelize = sequelize;
db.Sequelize = Sequelize;

module.exports = db;

当我尝试将此数据库从 index.js 传递到控制器中的 Books 模型时，我得到的错误是：

 const model = require(path.join(__dirname, file))(sequelize, Sequelize.DataTypes);
                                                     ^

TypeError: Class constructor model cannot be invoked without 'new'

我应该将什么传递给参数以及从哪里传递？

标签： javascriptnode.jsexpresssequelize.js

javascript - 从 postgres 获得对 sequelize findall 的空响应

问题描述

解决方案

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