javascript - Node 应用程序无法识别 Sequelize 中间件代码

Question

我是sequelize的新手，我创建了一个名为“db.js”的中间件，它连接到一个名为“users”的mysql表。每次我尝试运行 app.js 时，都会收到此错误:“TypeError:app.use() 需要中间件函数”。

但是，我有一个中间件功能。请参阅下面的代码:我错过了什么吗？我最后有 module.exports 对象。

我应该初始化sequelize吗？

db.js 文件

const Sequelize = require("sequelize");
const mysql = require("mysql");
const mysql2 = require("mysql2");

const db = {}
const sequelize = new Sequelize("smalldata", "root", "xxxx", {
    host: "localhost",
    dialect: "mysql",
    operatorsAliases: false,

    pool: {
        max: 5,
        min: 0,
        acquire: 30000,
        idle: 90000
    }
})

sequelize
    .authenticate()
    .then(() => {
        console.log('Connection has been established successfully.');
    })
    .catch(err => {
        console.error('Unable to connect to the database:', err);
    });

db.sequelize = sequelize
db.Sequelize = Sequelize

module.exports = db;

app.js 文件

const sequelize = require("sequelize");
const db = require("./middleware/db");
const express = require("express");

//Initialize Middleware
app.use(cors());
app.use(expressLayouts);
app.use(logger);
app.use(db);

user.js 文件

const Sequelize = require("sequelize");
const db = require("./db");

const User = db.sequelize.define(
    'users',
    {
        id: {
            type: Sequelize.INTEGER,
            primaryKey: true,
            autoIncrement: true
        },

        first_name: {
            type: Sequelize.STRING
        },

        last_name: {
            type: Sequelize.STRING
        },

        email: {
            type: Sequelize.STRING
        },

        password: {
            type: Sequelize.STRING
        }
    },

    {
        timestamps: true
    },
)

// Note: using `force: true` will drop the table if it already exists
User.sync({ force: true }).then(() => {
    // Now the `users` table in the database corresponds to the model 
    definition
    return User.create({
        first_name: 'John',
        last_name: 'Hancock',
        email:'johnhancock@gmail.com',
        password:'johnny'
    });
});

module.exports = User

Answer 1

我发现错误:app.js 文件中大写错误:const Sequelize = require("sequelize");

而不是:const Sequelize = require("sequelize");