Angular is client side framework, so you cannot connect to database using angular. What you have to do is create webservices / api in any language you prefer such as: python,php or as you are using angular and you maybe more comfortable with javascript based projects,you can look into node.js + express with mysql package to connect to database and create endpoints to connect with through angular to get the data. You may have look at the link below to learn more about node.js

Node.js + mysql rest api build

Your question not clear enough. Can you provide more context on what you really want to achieve?