通过将模型逻辑与模型配置分离来解决问题

Question

我通过连接到主机并将所有模型导入一个文件然后在与模型交互时调用该文件来遵循 sequelize 最佳实践。出于某种原因，这似乎导致了一个问题，因为我在对 sequelize 变量使用 define 方法时遇到错误，我运行使用包含两个逻辑的文件进行测试，我是能够添加用户。

错误：

TypeError: Cannot read property 'define' of undefined
    at new module.exports (/Users/user/Desktop/Projects/node/ann/app/models/ann-model.js:3:27)
    at /Users/user/Desktop/Projects/node/ann/app/controllers/appRoutes.js:13:20

这是我的包含数据库连接的文件 (dbIndex.js)：

var Sequelize = require('sequelize');
var sequelize = new Sequelize('dbname', 'user', 'pwd', {
    host:'localhost',
    port:'3306',
    dialect: 'mysql'
});

sequelize
        .authenticate()
        .then(function(err) {
            if (!!err) {
                console.log('Unable to connect to the database:', err)
            } else {
                console.log('Connection has been established successfully.')
            }
        });

var db = {}

db.Ann = sequelize.import(__dirname + "/ann-model");

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

module.exports = db;

这是模型文件(ann-model.js):

module.exports = function(sequelize, DataTypes) {

var Ann = sequelize.define('ann', {
    ann_id: {
        type: DataTypes.INTEGER,
        primaryKey: true
    },
    ann_date: DataTypes.DATE,
}, {
    freezeTableName: true
});
    return Ann;
}

这是我使用 POST 方法调用模型的地方。

(appRoutes.js):

var express = require('express');
var appRoutes   = express.Router();
var Annotation = require('../models/ann-model');

appRoutes.route('/') 

    .get(function(req, res){
        res.render('pages/activity-feed.hbs');
    })

    .post(function(req, res){

        var ann = new Ann();

        ann.ann_date = req.body.ann-date;


        annotation.save(function(err){
            if (err)
                res.send(err);
        });
    });

module.exports = appRoutes;

在一个文件中结合逻辑和建模的测试文件：

var Sequelize = require('sequelize');
var sequelize = new Sequelize('dbname', 'user', 'pwd', {
    host:'localhost',
    port:'3306',
    dialect: 'mysql'
});


var Ann = sequelize.define('ann', {
    ann_id: {
        type: Sequelize.INTEGER,
        primaryKey: true
    },
    ann_date: Sequelize.DATE,
}, {
    freezeTableName: true
});

sequelize.sync().then(function(){
    return Ann.create({
        ann_id: 3,
        discovery: 'This is a test.'
    });
}).then(function(tation) {
    console.log(tation.get({
        plain: true
    }));
});

Answer 1

我认为你的 post 方法有问题，但是结构真的很混乱所以你可以这样做

models/index.js

"use strict";

var fs        = require("fs");
var path      = require("path");
var Sequelize = require("sequelize");
var env       = process.env.NODE_ENV || "development";
var config    = require(__dirname + '/../config/config.json')[env];
var sequelize = new Sequelize(config.database, config.username, config.password, config);
var db        = {};

fs
  .readdirSync(__dirname)
  .filter(function(file) {
    return (file.indexOf(".") !== 0) && (file !== "index.js");
  })
  .forEach(function(file) {
    var model = sequelize.import(path.join(__dirname, file));
    db[model.name] = model;
  });

Object.keys(db).forEach(function(modelName) {
  if ("associate" in db[modelName]) {
    db[modelName].associate(db);
  }
});
db.sequelize = sequelize;
db.Sequelize = Sequelize;

module.exports = db;

models/ann-model.js

"use strict";

module.exports = function(sequelize, DataTypes) {

var Ann = sequelize.define('ann', {
    ann_id: {
        type: DataTypes.INTEGER,
        primaryKey: true
    },
    ann_date: DataTypes.DATE,
}, {
    freezeTableName: true
});
    return Ann;
}

routes/index.js

var express = require('express');
var appRoutes   = express.Router();
var models = require('../models');

appRoutes.route('/') 

    .get(function(req, res){
        res.send('ok');
    })

    .post(function(req, res){

      models.ann
      .build({ ann_id: 55, ann_date: new Date() })
      .save()
      .then(function(anotherTask) {
        res.send("POST OK"); 
      }).catch(function(error) {
        res.send(error);
      })

    });

module.exports = appRoutes;

通过将模型逻辑与模型配置分离来解决问题

Sequelize Issue By Separating Model Logic from Model Configuration

node.js

sequelize.js