node作为一款可以兼容前后端的js语言,在做持久层操作上和Java比较类似,下面就简单介绍一下项目中的数据库配置操作.

首选使用express框架自动创建一个测试项目,并在目录下建立一个专门存放数据库配置的配置文件,比如:db.js  代码如下 

/*
* 数据库配置文件
* @Author: zth
* @Date:   2019-02-18 10:50:45
* @Last Modified by:   zth
* @Last Modified time: 2019-03-05 11:35:42
*/// Mysql 配置项
var mysql = require("mysql");
var pool = mysql.createPool({host:"localhost",user:"root",password:"123456",database:"elink_platform"
});/*** mysql查询类* @Author   zth* @DateTime 2019-03-05T11:34:58+0800* @param    {string}                 sql      查询语句*/
function query(sql,callback) {pool.getConnection(function(err,connection) {connection.query(sql, function (err,rows) {callback(err,rows);connection.release();});});
}// MongoDB配置项
var MongoClient = require('mongodb').MongoClient;
const url = 'mongodb://localhost:27017/farmDB';
const dbName = 'farmDB';  /*** MongoDB查询类* @Author   zth* @DateTime 2019-03-05T10:23:09+0800* @param    {[string]}  collection [数据集合名称]* @param    {[json]}    query      [查询语句json对象]*/
function find(collectionName, query) {MongoClient.connect(url, {useNewUrlParser:true}, function(err, client) { const db = client.db(dbName);const collection = db.collection(collectionName);collection.find(query).toArray(function(err, docs) {console.log(docs);});
});
}exports.query = query;
exports.find = find;

这里为了测试就简单创建两个查询的方法,以调试通过为目的.

其次在需要的路由文件中引入db.js,然后进行调用即可.

var express = require('express');
var router = express.Router();var db = require("../config/db");

最后处理返回的结果集,这个和平时注册请求后端接口的数据处理一致.

router.get('/haveJobTypes', function(req, res, next) {console.log(JSON.stringify(req.query));var sql = "SELECT COALESCE (b.job_type_code,'sum') AS job_type_code,SUM(b.job_mu) AS job_mu FROM farm_job_info b LEFT JOIN farm_terminal_reg_info a ON a.car_id=b.car_id AND a.flag=1 AND b.flag=1 WHERE a.org_code IN (SELECT t1.CODE FROM sys_org_info t1,(SELECT @pcode :=CODE FROM sys_org_info WHERE id = " + req.query.orgId + ") t2 WHERE t1.CODE LIKE CONCAT(@pcode,'%')) AND b.job_date BETWEEN '" + req.query.startTime + "' AND '" + req.query.endTime + "' GROUP BY b.job_type_code WITH ROLLUP";db.query(sql, function(err, result){const obj = {status: err ? 1 : 0,data: err ? [] : result}res.json(obj);});var queryJson = { "carId": "HD146555" };db.find('terminal', queryJson, function(err, result) {console.log("result");console.log(result);})
});