ON DELETE SET NULL in postgres

Cascade remove issues in Entity Framework - Foreign key set to null

I have the following Model which I mapped with the Entity Framework: Mitglied -> Auftrag -> Teilprojekt...I have set up everything in the database with foreign keys and "on delete cascade". If I perform some tests on the database everything works fine. The problem arises as soon as I use the Entity Framework to add and especially delete objects. Co...

Why is my Entity Framework Code First proxy collection null, and I can't seem to get it to work?

I am using DBContext and have two classes whose properties are all virtual. I can see in the debugger that I am getting a proxy object when I query the context. However, a collection property is still null when I try to add to it. I thought that the proxy would ensure that collection is initialized....Because my Poco object can be used outside of i...

Entity Framework deletes related entities in a cascading manner.

I have an issue with deletion in Entity Framework. In short, EF explicitly tries to delete an entity from the database even though I've explcitly configured EF to use cascading deletes in the database....My design:...I have three entity types, ...MainEntity..., ...EntityTypeA... and ...EntityTypeB.... EF has been configured to use cascade deletion ...

Entity Framework will only set related entity property to "null" if I first get the property

Edit... This seems to occur for ...any... Entity property that references another entity in one direction. In other words, for the below example, the fact that ...Bar... overrides Equality appears to be irrelevant....Suppose I have the following classes:...public class Foo { public int? Id { get; set; } public virtual Bar { get; set; } }...

Referential Integrity Constraint violation when attempting to set a FK to null

I am trying to update an entity in EF6. I have read that if I wish to change a ForeignKey property, I have to then ensure the Navigation Property is the correct one, or set it to null....I have taken the set to null approach, but I still receive the Referential Integrity Constraint Exception:...A referential integrity constraint violation occurred:...

"Object reference not set to an instance of an object" - but nothing is null?

Yeah, you probably think; "God, another one?". ...Yes, another one...."Object reference not set to an instance of an object."...I've been working with EF6 lately and after developing for some time, I found that a little bit more optimization was needed. Alot has been reworked without problems, but it seems I can't figure out this one....In my appli...

How to update FK to null when deleting optional related entity

I'm reasonably new to EF, and struggling a little to facilitate deleting my objects. My two objects and associated DbContext look as follows:...public class Context: DbContext { public Context() : base(){} public DbSet<Person> Persons {get;set;} public DbSet<Vehicle> Vehicles {get;set;} } public class Person { public int PersonID {g...

Delete the foreign key data when the data in the foreign table is deleted

I have 2 database tables, and I want when I delete a data in the table where the foreign key is pointing (where the primary key is), the foreign key pointing to that data also be deleted.... [HttpPost, ActionName("Delete")] [ValidateAntiForgeryToken] public async Task<ActionResult> DeleteConfirmed(int id) { Report report = a...

Entity Framework: how to delete related entity upon update or delete of 'generic' parent

I have a ...Product... class, which contains a ...Picture... property. Other classes may also have a picture, e.g. a ...Customer... can have a ...Picture.......Product.cs:...public class Product { public Picture Picture { get; set; } } ...Customer.cs:...public class Customer { public Picture Picture { get; set; } } ...Picture.cs:...public...

setting a property being passed as a parameter to null

I have the following method:... public bool Method(object obj){ var objType = obj.GetType(); //do some reflection to get obj properties for some logic ... if(someCondition) { obj = null; return false; } if(condition2){ return true;} return false; } ...Method call:...var someObj = SomeObj(); Me...