implement basic day query

backend/index.js

@@ -0,0 +1,34 @@
+const express = require('express')
+const app = express();
+const status = require('http-status');
+var mysql = require('mysql');
+var connection = mysql.createConnection({
+    host: 'localhost',
+    user: 'simcompanies',
+    password: '',
+    database: 'simcompanies'
+});
+
+app.get('/API/day', function (req, res) {
+    var date = new Date(req.query.date);
+    const kind = parseInt(req.query.kind);
+    if (date instanceof Date && Number.isInteger(kind))
+        if (!isNaN(date.getTime()) && kind >= 1 && kind <= 113) {
+            const daybegin = `${date.getFullYear()}-${date.getMonth() + 1}-${date.getDate()}`;
+            date.setDate(date.getDate() + 1);
+            const dayend = `${date.getFullYear()}-${date.getMonth() + 1}-${date.getDate()}`;
+            const querystring = `SELECT time, price FROM market WHERE kind = ${kind} AND time > "${daybegin}" AND time < "${dayend}"`
+            connection.query(querystring, function (error, results, fields) {
+                if (error) {
+                    throw error;
+                }
+                res.send(results);
+            });
+        }
+        else
+            res.status(status.BAD_REQUEST).send("invalid data provided");
+    else
+        res.status(status.BAD_REQUEST).send("invalid data provided");
+});
+
+app.listen(3000);