How many instances of an entity can EF Core track?
You can view this article’s sample on GitHub. EF Core can only track one instance of any entity with a given primary key value.
When to use an auto generated entity key?
With auto-generated keys. The value of an automatically generated key can often be used to determine whether an entity needs to be inserted or updated. If the key has not been set (that is, it still has the CLR default value of null, zero, etc.), then the entity must be new and needs inserting.
Is there a way to delete entities in EF Core?
Delete can be tricky to handle since often the absence of an entity means that it should be deleted. One way to deal with this is to use “soft deletes” such that the entity is marked as deleted rather than actually being deleted. Deletes then becomes the same as updates. Soft deletes can be implemented in using query filters.
Can a entity be marked for update but not insert?
The Update method normally marks the entity for update, not insert. However, if the entity has a auto-generated key, and no key value has been set, then the entity is instead automatically marked for insert.
What is the best way to check if object exists in Entity Framework?
What is the best way to check if an object exists in the database from a performance point of view? I’m using Entity Framework 1.0 (ASP.NET 3.5 SP1). If you don’t want to execute SQL directly, the best way is to use Any (). This is because Any () will return as soon as it finds a match.
When to use insert or update in EF Core?
If it is known whether or not an insert or update is needed, then either Add or Update can be used appropriately: However, if the entity uses auto-generated key values, then the Update method can be used for both cases: The Update method normally marks the entity for update, not insert.
What does the setvalues call do in EF Core?
The SetValues call will mark the entity to be updated as needed. SetValues will only mark as modified the properties that have different values to those in the tracked entity. This means that when the update is sent, only those columns that have actually changed will be updated.