How to create a Drop down

I want to create a 3 drop down’s that should get data from a database in a way like on selecting First Drop down the Second drop down data should be populated and that data has to come from DB and based on the Second Drop Down the Third DD should get populated. Can anyone please say me where i need to learn to get this or just help me with this (angularjs and mysql) please help me.
Thanks in advance

Source: AngularJS