'use strict';
const Sequelize = require('sequelize');
var Factory = {
defaultHooks: {
beforeCreate: (record) => {
let now = Date.now();
// 如果是新创建的数据
record.createdAt = now;
record.updatedAt = now;
record.version = 0;
console.log('CREATE');
},
beforeUpdate: (record) => {
let now = Date.now();
// 如果是更新现有数据
record.updatedAt = now;
record.version = 0;
console.log('UPDATE');
},
beforeValidate: (record) => {
if (!record.createdAt) {
record.createdAt = 0;
}
if (!record.updatedAt) {
record.updatedAt = 0;
}
if (!record.version) {
record.version = 0;
}
}
},
/**
* 包装Model
* @param {string} modelName 表名
* @param {*} modelWithName 带名字的model对象
*/
packModel: (modelWithName, sequelize) => {
let modelName = modelWithName.name;
let model = modelWithName.model;
let hooks = modelWithName.hooks;
let packedModel = {};
// 为每个字段加上非空条件（除非显式指定可以为空）
for (const columnName in model) {
if (model.hasOwnProperty(columnName)) {
const columnType = model[columnName];
if (typeof columnType === 'object' && columnType.type) {
// 加上非空（除非显式指定可以为空）
columnType.allowNull = columnType.allowNull || false;
// 将修改后的字段添加到包装后Model中
packedModel[columnName] = columnType;
} else {
// 加上非空
packedModel[columnName] = {
type: columnType,
allowNull: false
};
}
}
}
// 加上主键id
packedModel.id = {
type: Sequelize.INTEGER,
primaryKey: true,
autoIncrement: true
};
// 创建于
packedModel.createdAt = { type: Sequelize.BIGINT, allowNull: false };
// 修改于
packedModel.updatedAt = { type: Sequelize.BIGINT, allowNull: false };
// 版本号
packedModel.version = { type: Sequelize.INTEGER, allowNull: false };
if (hooks) {
// 如果用户自定义了hook则进行合并
for (const key in Factory.defaultHooks) {
if (Factory.defaultHooks.hasOwnProperty(key)) {
const defaultHookMethod = Factory.defaultHooks[key];
if (hooks.hasOwnProperty(key)) {
// 如果用户定义的hook属性和默认hook属性重复
let hookMethod = hooks[key];
hooks[key] = (record) => {
// 则先运行默认hook再运行用户定义hook
defaultHookMethod(record);
hookMethod(record);
};
} else {
// 如果不重复则直接应用以默认hook
hooks[key] = defaultHookMethod;
}
}
}
} else {
// 如果用户没有自定义hook则使用默认hook
hooks = Factory.defaultHooks;
}
return sequelize.define(modelName, packedModel, {
timestamps: false,
hooks: hooks
});
}
}
module.exports = Factory;
一个简单学习NodeJs中使用MySQL的例子.zip （9个子文件） 
kwan1117 .vscode 
launch.json 415B main.js 353B package.json 474B package-lock.json 14KB models model_student.js 380B _config.js 166B _manager.js 2KB _factory.js 4KB .gitignore 13B资源评论
