Its always advised to write your database connection code in separate.
And server.js page you can invoke function using ().like this.
const db = require("./db")();
Its always recommended to use environment variable of db url.
like this process.env.MONGO_URL
const mongoose = require("mongoose");
mongoose.set('strictQuery', true)
const db = async () => {
try {
await mongoose.connect(process.env.MONGO_URL, {
useNewUrlParser: true,
useUnifiedTopology: true,
});
console.log('database connected ');
} catch (error) {
console.log(error);
}
};
module.exports = db;