how to connect mongoose to database code example

Example 1: mongoose connection node

mongoose.connect('mongodb://localhost/myapp', { useNewUrlParser: true, useUnifiedTopology: true });

Example 2: mongoose.connect

mongoose.connect('mongodb://localhost:27017/myapp', {useNewUrlParser: true});

Example 3: Mongoose db connect

mongoose.connect('mongodb://username:password@host:port/database?options...', {useNewUrlParser: true});