本文实例讲述了nodejs nedb 封装库与使用方法。分享给大家供大家参考，具体如下：

libs/nedb.js

const Datastore = require('nedb');function DB(database) { let options = { filename: database, autoload: true, }; this.db = new Datastore(options);}DB.prototype.limit = function(offset, limit) { this.offset = offset || 0; this.limit = limit || 15; return this;}DB.prototype.sort = function(orderby) { this.orderby = orderby; return this;}DB.prototype.find = function(query, select) { return new Promise((resolve, reject) => { let stmt = this.db.find(query || {}); if (this.orderby !== undefined) { stmt.sort(this.orderby); } if (this.offset !== undefined) { stmt.skip(this.offset).limit(this.limit); } if (select != undefined) { stmt.projection(select || {}); } stmt.exec((err, docs) => { if (err) { return reject(err); } resolve(docs); }) })};DB.prototype.findOne = function(query, select) { return new Promise((resolve, reject) => { let stmt = this.db.findOne(query || {}); if (this.sort !== undefined) { stmt.sort(this.sort); } if (select != undefined) { stmt.projection(select || {}); } stmt.exec((err, doc) => { if (err) { return reject(err); } resolve(doc); }) })}DB.prototype.insert = function(values) { return new Promise((resolve, reject) => { this.db.insert(values, (err, newDoc) => { if (err) { return reject(err); } resolve(newDoc); }) })}DB.prototype.update = function(query, values, options) { return new Promise((resolve, reject) => { this.db.update(query || {}, values || {}, options || {}, (err, numAffected) => { if (err) { return reject(err); } resolve(numAffected); }) });}DB.prototype.remove = function(query, options) { return new Promise((resolve, reject) => { this.db.remove(query || {}, options || {}, (err, numAffected) => { if (err) { return reject(err); } resolve(numAffected); }) });}module.exports = (database) => { return new DB(database);}

test.js

const db = require('./libs/nedb')('testdb');(async function() { await db.insert({number: 12}); await db.insert({number: 11}); await db.insert({number: 13}); let res = await db.sort({number: -1}).limit(0, 2).find(); console.log(res);})();

执行命令

nodemon test.js

希望本文所述对大家node.js程序设计有所帮助。