【前端必会】使用indexedDB，降低环境搭建成本 _生活百科

背景

学习前端新框架、新技术。如果需要做一些数据库的操作来增加demo的体验（CURD流程可以让演示的体验根据丝滑）
最开始的时候一个演示程序我们会调用后台，这样其实有一点弊端，就是增加了开发和维护成本，简单的一个demo不应该劳师动众
后来我会在demo中使用一些websql，奈何，websql也真的是没前景了。代码写起来也不是特别好
下面来介绍下今天的主角indexedDB和jsStore

介绍

indexedDB可以给浏览器本地存储的能力，并且容量还比较大。
jsStore只是众多封装的indexedDB库中的一个。可以用一种类似SQL的感觉操作数据

开始package.json

{"name": "npm1","version": "1.0.0","description": "","main": "index.js","scripts": {"lint": "eslint scripts/**","fix": "eslint scripts/** --fix","serve": "webpack serve"},"dependencies": {"jsstore": "^4.4.4","lodash": "^4.17.21"},"devDependencies": {"css-loader": "^6.7.1","eslint": "^8.23.1","eslint-config-google": "^0.14.0","eslint-config-prettier": "^8.5.0","eslint-plugin-prettier": "^4.2.1","file-loader": "^6.2.0","html-webpack-plugin": "^5.5.0","prettier": "2.7.1","style-loader": "^3.3.1","webpack": "^5.74.0","webpack-cli": "^4.10.0","webpack-dev-server": "^4.11.1"},"author": "","license": "ISC"}

webpack配置，添加了devServer配置

//webpack.config.js const path = require("path");const HtmlWebpackPlugin = require("html-webpack-plugin");module.exports = {context: path.resolve(__dirname),devServer: {static: {directory: path.join(__dirname, "dist"),},compress: true,port: 9000,},mode: "production",optimization: {minimize: false,},entry: "./src/main.js",target: ["web", "es5"],output: {clean: true,filename: "bundle.js",path: path.resolve(__dirname, "dist"),},plugins: [new HtmlWebpackPlugin({template: "index.html",}),],module: {rules: [{test: /\.css$/i,use: ["style-loader", "css-loader"],},],},};

jsStore链接帮助类，结合webpack+webworker 。安装了file-loader

//store-connection.js import { Connection } from "jsstore";const getWorkerPath = () => {// return dev build when env is developmentif (process.env.NODE_ENV === "development") {return require("file-loader?name=scripts/[name].[hash].js!jsstore/dist/jsstore.worker.js");} else {// return prod build when env is productionreturn require("file-loader?name=scripts/[name].[hash].js!jsstore/dist/jsstore.worker.min.js");}};const workerPath = getWorkerPath().default;export const connection = new Connection(new Worker(workerPath));

主逻辑

//main.js import { connection } from "./store-connection";async function init() {var dbName = "JsStore_Demo";var tblProduct = {name: "Product",columns: {// Here "Id" is name of columnid: { primaryKey: true, autoIncrement: true },itemName: { notNull: true, dataType: "string" },price: { notNull: true, dataType: "number" },quantity: { notNull: true, dataType: "number" },},};var database = {name: dbName,tables: [tblProduct],};const isDbCreated = await connection.initDb(database);if (isDbCreated === true) {console.log("db created");// here you can prefill database with some data} else {console.log("db opened");}var value = https://www.huyubaike.com/biancheng/{itemName:"Blue Jeans",price: 2000,quantity: 1000,};var insertCount = await connection.insert({into: "Product",values: [value],});console.log(`${insertCount} rows inserted`);// results will be array of objectsvar results = await connection.select({from: "Product",});results.forEach((item) => {console.log(item);});}window.addEventListener("load", function () {console.log(connection);init();});

数据已经存进去了