Entity Framework The object cannot be deleted Exception
Exception: The object cannot be deleted because it was not found in the ObjectStateManager
When an entity is fetched and deleted using different DbContext object, then it throws an exception The object cannot be deleted because it was not found in the ObjectStateManager.
Customer deletedCustomer = null; using (var context = new EntityContext()) { deletedCustomer = context.Customers.Where(c => c.CustomerID == 3).FirstOrDefault(); } using (var context = new EntityContext()) { context.Customers.Remove(deletedCustomer); context.SaveChanges(); }
In the above example, the customer entity is fetched in one DbContext instance, and then it is removed/deleted from the database in another DbContext instance.
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Solution
To avoid the above exception, make sure that either entity is fetched and deleted in the same DbContext instance or an entity is attached to the context before removing it.
Use Same DbContext Instance
using (var context = new CustomerContext()) { var deletedCustomer = context.Customers.Where(c => c.CustomerID == 3).FirstOrDefault(); context.Customers.Remove(deletedCustomer); context.SaveChanges(); }
Attach Before Deleting
Customer deletedCustomer = null; using (var context = new EntityContext()) { deletedCustomer = context.Customers.Where(c => c.CustomerID == 3).FirstOrDefault(); } using (var context = new EntityContext()) { context.Customers.Attach(deletedCustomer); context.Customers.Remove(deletedCustomer); context.SaveChanges(); }
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