c# - Why is the Up() method abstract and the Down() method virtual in the DbMigration class -

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if @ signature of abstract class dbmigration in system.data.entity.migrations namespace:

public virtual void down(); public abstract void up();

you'll see down() marked virtual , up marked abstract. difference between virtual , abstract abstract function can have functionality in it.

what kind of functionality can up() function have default , why isn't case th down() function.

you need override up() while overriding down() optional. makes sense database migration instructions.

see what difference between abstract function , virtual function?.


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