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带有Sequelize的Node.js数据库模块

require sequelize.js async-await node.js javascript

Nicolas Bouvrette · 技术社区 · 6 年前

为了提高代码的可读性,我尝试将所有与数据库相关的代码移到一个文件中。使用Sequelize作为ORM。我想这个文件,当包括提供一个随时可用的数据库。表模式也由Sequelize管理,这就是为什么我使用 sync()

文件:test.js

const database = require('./dbInit');

(async () => {

    await database.testTable.max('id').then((maxId) => {
        console.log(maxId);
    });

})();

文件:dbInit.js

const Sequelize = require('sequelize');

const sequelize = new Sequelize('mysql://root:root@localhost:3306/test');

const testTable = sequelize.import('testTable');

const database = {
    sequelize: sequelize,
    testTable: testTable,
};

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

sequelize.sync();

module.exports = database;

文件:testTable.js

const Sequelize = require('sequelize');

module.exports = (sequelize, DataTypes) => {
    return sequelize.define('testTable',
        {
            id: {
                type: Sequelize.BIGINT(19).UNSIGNED,
                primaryKey: true,
                autoIncrement: false,
            }
        }
    );
};

当我按原样运行代码时,在没有创建表的情况下,我可以从日志中看到查询是在数据库连接可用之前运行的:

> node .\test.js
Executing (default): SELECT 1+1 AS result
Executing (default): SELECT max(`id`) AS `max` FROM `testTables` AS `testTable`;
Connection to the database has been established successfully.
(node:1572) UnhandledPromiseRejectionWarning: SequelizeDatabaseError: Table 'test.testtables' doesn't exist

max('id') 电话):

await database.sequelize.sync();

调用所有其他需要数据库连接的文件?

1 回复 | 直到 6 年前

num8er 6 年前

由于异步行为,所有要执行的操作:

连接
同步

将模型文件放置到: db db/schemas/User.js

并为数据库生成模块文件: db/index.js

const Sequelize = require('sequelize');

const sequelize = new Sequelize('mysql://root:root@localhost:3306/test');

const connect = async () => {
  try {
    await sequelize.authenticate();
    await sequelize.sync();

    console.log('Connection to the database has been established successfully.');
  }
  catch (error) {
    console.error(error.message);
    process.exit(-1);
  }
});

const model = name => database.models[name];

const User = sequelize.import('./schemas/User');

const database = {
    sequelize: sequelize,
    models: {User},
    connect,
    model
};

module.exports = database;

test.js

const db = require('./db');

(async () => {
    await db.connect();

    const User = db.model('User');

    const id = await User.max('id');

    console.log(id);
})();

你的问题是不同的-你想做数据库查询立即,所以你必须确保连接和同步建立成功。

AxDu 5 年前

Sequelize-DemoApp . 它是一个完全工作的全栈应用程序,专门用来演示和理解Sequelize.js及其与nodejs的集成