When you are familiar with CASE, you can make your SQL statement more flexible and reduce redundant semantics. CASE can be categorized into two cases. One is simple case CASE WHEN condition THEN result [WHEN···] [ELSE result] END; and the other one is searched case CASE expression WHEN value THEN result [WHEN···] [ELSE […]
This article introduces one of solid principles which is ISP (Interface Segregation Principle). It is better to build a small-sized interface than a heavy interface as a small-size interface is easier to refactor and decouple. Too many is better than too few For example, you have IAnimal interface which has three methods(eat, move and sleep)
This article will introduce one of solid principles DIP which is the abbreviation of Dependency Inversion Principle. High level modules should not depend upon low level modules. Both should depend upon abstractions. Abstractions should not depend upon details. Details should depend upon abstractions Interpretation: Use abstraction rather than concrete object Example: Say you go to