代码仓库： https://github.com/hilanmiao/LanMiaoDesktop

请先阅读这位作者的文章，基本是按照他的思路做的。 https://molunerfinn.com/electron-vue-3/#lowdb%E5%AE%9E%E9%99%85%E4%BD%BF%E7%94%A8%E7%9A%84%E5%9D%91

lodash 中文文档 https://www.html.cn/doc/lodash/ http://lodash.think2011.net/assign

lodash-id 中文文档 https://www.helplib.com/GitHub/article_106283

初始化

核心代码如下：

import Datastore from 'lowdb'
import LodashId from 'lodash-id'
import FileSync from 'lowdb/adapters/FileSync'
import path from 'path'
import fs from 'fs-extra'
// 引入remote模块
import { app, remote } from 'electron'
// package.json
import pkg from '../../package.json'

// 根据process.type来分辨在哪种模式使用哪种模块
const APP = process.type === 'renderer' ? remote.app : app

// 获取electron应用的用户目录
const STORE_PATH = APP.getPath('userData')
// console.log(STORE_PATH)
// C:\Users\JD\AppData\Roaming\Electron

if (process.type !== 'renderer') {
// 如果不存在路径
if (!fs.pathExistsSync(STORE_PATH)) {
// 就创建
fs.mkdirpSync(STORE_PATH)
}
}

// 以同步的方式初始化lowdb读写的json文件名以及存储路径
const adapter = new FileSync(path.join(STORE_PATH, `/${pkg.name}_lowdb.json`))

// lowdb接管该文件
const db = Datastore(adapter)
// 通过._mixin()引入lodash_id唯一id插件
db._.mixin(LodashId)

// 初始化数据
if(!db.has('user').value()) {
db.set('user',[{userId: 'admin', password: '123456'}]).write()
}

if(!db.has('category').value()) {
db.set('category', []).write()
}

if(!db.has('assets').value()) {
db.set('assets', []).write()
}

if(!db.has('incomeAndExpenditure').value()) {
db.set('incomeAndExpenditure', []).write()
}

export default db // 暴露出去

效果：

编写api并使用

结合vuetify的datatable组件做了个CRUD的例子，具体请查看源码。

文件结构如下，api也可以放到renderer里，因为我主进程也可能会用到，所以我这边主要把它拿出来了，不一定合适，看个人习惯吧。

核心代码如下，insert、upsert、removeWhere等其实都是lodash-id这个模块封装的，你可以点击看看，其实里面的代码还是lodash的，你也可以封装自己的方法。

import db from '../datastore'

export function getCategoryById(id) {
return new Promise((resolve, reject) => {
try {
const collection = db.get('category')
const category = collection.getById(id).value()
resolve({
code: 200,
data: category
})
} catch (err) {
return reject({
code: 400,
message: err.message
})
}
})
}

export function getCategoryWhere(attrs) {
return new Promise((resolve, reject) => {
try {
const collection = db.get('category')
const categoryList = collection.filter(attrs).value()
resolve({
code: 200,
data: categoryList
})
} catch (err) {
return reject({
code: 400,
message: err.message
})
}
})
}

export function getCategoryAll() {
return new Promise((resolve, reject) => {
try {
const collection = db.get('category')
const categoryAll = collection.value()
resolve({
code: 200,
data: categoryAll
})
} catch (err) {
return reject({
code: 400,
message: err.message
})
}
})
}

export function getCategoryPagination(pagination, whereAttrs) {
return new Promise((resolve, reject) => {
try {
const collection = db.get('category')
const total = collection.size().value()
const categoryList = collection
.filter(o => {
// 模糊查询
return o.category.match(whereAttrs.category)
})
.orderBy(pagination.sortBy, pagination.descending ? 'desc' : 'asc')
.chunk(pagination.rowsPerPage === -1 ? total : pagination.rowsPerPage)
.take(pagination.page)
.last() // 因为上面用了chunk，是个二维数组，所以这里取最后一个
.value()
resolve({
code: 200,
data: {total: total, list: categoryList}
})
} catch (err) {
return reject({
code: 400,
message: err.message
})
}
})
}

export function postCategory(document) {
return new Promise((resolve, reject) => {
try {
const collection = db.get('category')
const category = collection.find({category: document.category}).value()
if(category) {
return reject({
code: 400,
message: 'This classification already exists'
})
}
const newCategory = collection.insert(document).write()
resolve({
code: 200,
data: newCategory
})
} catch (err) {
return reject({
code: 400,
message: err.message
})
}
})
}

export function postOrPutCategory(document) {
return new Promise((resolve, reject) => {
try {
const collection = db.get('category')
if(collection.find({category: document.category}).value()) {
return reject({
code: 400,
message: 'This classification already exists'
})
}
const newCategory = collection.upsert(document).write()
resolve({
code: 200,
data: newCategory
})
} catch (err) {
return reject({
code: 400,
message: err.message
})
}
})
}

export function putCategoryById(id, attrs) {
return new Promise((resolve, reject) => {
try {
const collection
3ff7
= db.get('category')
if(collection.find({category: attrs.category}).value()) {
return reject({
code: 400,
message: 'This classification already exists'
})
}
const newCategory = collection.updateById(id, attrs).write()
resolve({
code: 200,
data: newCategory
})
} catch (err) {
return reject({
code: 400,
message: err.message
})
}
})
}

export function putCategoryWhere(whereAttrs, attrs) {
return new Promise((resolve, reject) => {
try {
const collection = db.get('category')
if(collection.find({category: attrs.category}).value()) {
return reject({
code: 400,
message: 'This classification already exists'
})
}
const newCategory = collection.updateWhere(whereAttrs, attrs).write()
resolve({
code: 200,
data: newCategory
})
} catch (err) {
return reject({
code: 400,
message: err.message
})
}
})
}

export function replaceCategoryById(id, attrs) {
return new Promise((resolve, reject) => {
try {
const collection = db.get('category')
const newCategory = collection.replaceById(id, attrs).write()
resolve({
code: 200,
data: newCategory
})
} catch (err) {
return reject({
code: 400,
message: err.message
})
}
})
}

export function deleteCategoryById(id) {
return new Promise((resolve, reject) => {
try {
const collection = db.get('category')
collection.removeById(id).write()
resolve({
code: 200
})
} catch (err) {
return reject({
code: 400,
message: err.message
})
}
})
}

export function deleteCategoryByIds(ids) {
return new Promise((resolve, reject) => {
try {
const collection = db.get('category')
ids.forEach(id => {
collection.removeById(id).write()
})
resolve({
code: 200
})
} catch (err) {
return reject({
code: 400,
message: err.message
})
}
})
}

export function deleteCategoryWhere(whereAttrs) {
return new Promise((resolve, reject) => {
try {
const collection = db.get('category')
const categoryList = collection.removeWhere(whereAttrs).write()
resolve({
code: 200,
data: categoryList
})
} catch (err) {
return reject({
code: 400,
message: err.message
})
}
})
}

说明

1. 这种微小型数据库，不大可能支持G级，网友说也就是几百MB，所以如果数据量很大，请切换到sqlite。其实写个博客，做个单机小系统足够了，大不了分几个库，反正都是些文件，甚至可以按照日期一天一个文件，当然这样就麻烦了。
2. 多表查询、分页，emmm，没有这些功能，所有的数据都已经在内存中了，随便折腾就好了......我代码中类似分页这种功能只是在模拟一些动作而已

转载于:https://my.oschina.net/u/3667677/blog/3054535