Repository pattern

https://msdn.microsoft.com/en-us/library/ff649690.aspx

https://medium.com/@krzychukosobudzki/repository-design-pattern-bc490b256006

https://martinfowler.com/eaaCatalog/repository.html

https://thinkinginobjects.com/2012/08/26/dont-use-dao-use-repository/

Links