How to change data from API by changing the parameters in URL ? Restfull API on javascript?

Question

I set a slash endpoint.

I want to make it so when the user enters: http/website.com/date=2019-08-01&station=41027&daysForward=5

be able to change three parameters to obtain different data.

date="first parameter"

station="second parameter"

daysForward="third parameter"

var express = require("express")
var app = express()
var mysql = require('mysql')

// Server port

var HTTP_PORT = 8000;
// Start server
app.listen(HTTP_PORT, () => {
    console.log("Server running on port %PORT%".replace("%PORT%",HTTP_PORT))
});

var con = mysql.createConnection({
    host: "192.168.0.1",
    port: "3333",
    user: "username",
    password: "pass"
});

con.connect(function(err) {
    if (err) throw err;
});

let selectCustomers = function (query, cb) {
    let aladinModel = '';
    if (query.date && query.station && query.daysForward) {
        con.query(`CALL aladin_surfex.Get_mod_cell_values_meteogram(${query.date},${query.station},${query.daysForward})`, function (err, result, fields) {
            if (err) throw err;
            console.log(result);
            aladinModel = result;
            return cb(aladinModel);
        });
    }
    else return cb(aladinModel);
};


// Root endpoint
app.get("/", (req, res, next) => {

selectCustomers(req.query, function (aladinModel) { res.json({aladinModel})

  const date = req.query.date;
  const station = req.query.station;
  const daysForward = req.query.daysForward;

  const query = `CALL aladin_surfex.Get_mod_cell_values_meteogram(${date}, ${station}, ${daysForward})`;
  con.query(query, function (err, result, fields) {
    if (err) throw err;
    aladinModel = result;
  });
  res.json({aladinModel})
});
app.use(function(req, res){
    res.status(404);
});

I got this error:

ReferenceError: aladinModel is not defined
    at app.get (C:\Users\Admin\node-express\server.js:54:13)
    at Layer.handle [as handle_request] (C:\Users\Admin\node-express\node_modules\express\lib\router\layer.js:95:5)
    at next (C:\Users\Admin\node-express\node_modules\express\lib\router\route.js:137:13)
    at Route.dispatch (C:\Users\Admin\node-express\node_modules\express\lib\router\route.js:112:3)
    at Layer.handle [as handle_request] (C:\Users\Admin\node-express\node_modules\express\lib\router\layer.js:95:5)
    at C:\Users\Admin\node-express\node_modules\express\lib\router\index.js:281:22
    at Function.process_params (C:\Users\Admin\node-express\node_modules\express\lib\router\index.js:335:12)
    at next (C:\Users\Admin\node-express\node_modules\express\lib\router\index.js:275:10)
    at expressInit (C:\Users\Admin\node-express\node_modules\express\lib\middleware\init.js:40:5)
    at Layer.handle [as handle_request] (C:\Users\Admin\node-express\node_modules\express\lib\router\layer.js:95:5)

Answer 1

Use the following code:

// Create express app
var express = require("express")
var app = express()
var mysql = require('mysql')

var date = '';
var station = '';
var daysForward = '';

// Server port

var HTTP_PORT = 8000;
// Start server
app.listen(HTTP_PORT, () => {
    console.log("Server running on port %PORT%".replace("%PORT%",HTTP_PORT))
});

var con = mysql.createConnection({
    host: "192.168.0.1",
    port: "3306",
    user: "user",
    password: "password"
});

con.connect(function(err) {
    if (err) throw err;
});

let selectCustomers = function (query, cb) {
    let aladinModel = '';
    if (query.date && query.station && query.daysForward) {
        con.query(`CALL aladin_surfex.Get_mod_cell_values_meteogram(${query.date},${query.station},${query.daysForward})`, function (err, result, fields) {
            if (err) throw err;
            console.log(result);
            aladinModel = result;
            return cb(aladinModel);
        });
    }
    else return cb(aladinModel);
};


// Root endpoint
app.get("/", (req, res, next) => {
    selectCustomers(req.query, function (aladinModel) {
        res.json({aladinModel})
    });
});
app.use(function(req, res){
    res.status(404);
});

Then use query parameters in your browser to pass date, station and daysForward like :

http://www.website.com?date=2019-08-01&station=41027&daysForward=5