Update file db.js

lib/db.js

 let mysql = require("mysql");
 let connection = mysql.createConnection({
-  host: "localhost",
-  user: "root",
-  password: "",
-  database: "work_collections",
+  host: process.env.DB_HOST,
+  user: process.env.DB_USER,
+  password: process.env.DB_PASS,
+  database: process.env.DB_NAME
 });
 
 connection.connect((error) => {