Unable to determine a valid ordering for dependent operations

Question

This is my model

public string Content { get; set; }

public Faq Reply { set; get; }

public int? ReplyId { get; set; }

public ICollection<Faq> Children { get; set; }

[ForeignKey("WriterId")]
public virtual UserProfile Writer { get; set; }

public virtual int? WriterId { get; set; }

public Status Status { get; set; }

[ForeignKey("DepartmentId")]
public virtual Department Department { get; set; }

public virtual int? DepartmentId { get; set; }

And this is my error

Unable to determine a valid ordering for dependent operations. Dependencies may exist due to foreign key constraints, model requirements, or store-generated values.

Answer 1

Another possible cause of this is if the foreign key property is set incorrectly.

For example, this can happen in the following scenario:

1. DepartmentId is set to zero or any other value that isn't a valid foreign key.
2. Department is either null or it is a Department object that contains a null value for its own DepartmentId property.
3. This configuration will cause Entity Framework to fail because it tries to find a Department that has a primary key of zero, which probably won't exist.

I ran into this exception once when I mapped one object to another and I incorrectly set the foreign key to zero instead of setting it to null.

I can't say that this configuration is what is causing your exception without seeing the actual values of the properties, but it is one possibility.

Answer 2

The simple way of avoiding this error is to create your primary object first, SaveChanges and then create your dependant object before calling SaveChanges again.

In this case create the object you show above first, SaveChanges, then create the Faq child object, add it to the collection and set it as the Reply and then SaveChanges again.

Answer 3

FWIW, I just spent a morning debugging a similar problem in EF 6.1. In my case, it was due to accidentally mixing objects owned by different contexts: setting the value of a navigation property in an object owned by one context, with an object owned by a different context.

Answer 4

In my case it was caused by nesting a new dependent object inside a another new object during create something like this:

var mySecondaryObject = new MyClass1 { ... };
var myPrimaryObject = new MyClass2 { Child = mySecondaryObject, ... };
dbContext.MyClass2Collection.Add(mySecondNewOject);
dbContext.SaveChanges();

Removing the nested reference and assigning the child in after the primary object was created solved the problem.

Answer 5

I had an entity class with a self-referencing navigation property. If the foreign key property associated with that navigation property was set to zero, it failed with this error.

If I set it to another invalid value like -1 or another value that did not exist in the database, it did NOT get this error. If I changed the navigation property to reference the wrong entity (so that it wasn't self-referencing), it did NOT get this error even using zero.

So apparently EF does something special with zero for self-referencing navigation properties. I know that the relation was defined correctly because my query that uses it pulled the correct data.

I was able to resolve my issue by using null instead of zero. That was really the proper value for me anyway.

Answer 6

Here is how we resolved this problem. We have entity which had defined sql query to populate entities. This entity had one column marked as key and had insert, update and delete CRUD methods. Key column was auto-populated with Oracle stored procedure and returned back in a cursor. We got this error when inserting new row.

After researching and investigating we found the problem was due to insert stored procedure being passed key column as a parameter value and was also been populated when stored procedure returned back key column auto generated value.

We removed the key column parameter from the insert SP and the problem was resolved.

Answer 7

This happened to me. EF 6.1/MVC

IN: public ActionResult Create(OfficeRecordModel officeData)

We have:

Office newOffice = new Office();
newOffice.Parent = officeData.Parent;
newOffice.Level = officeData.Level != null ? officeData.Level.Value : -1;
newOffice.ShortName = officeData.ShortName.Trim();
newOffice.LongName = officeData.LongName.Trim();
newOffice.IsActive = officeData.IsActive;                        
dbCtxt.Office.Add(newOffice);
dbCtxt.SaveChanges();

Boom I get: {"Unable to determine a valid ordering for dependent operations. Dependencies may exist due to foreign key constraints, model requirements, or store-generated values."}

Office entity:

public int ID { get; set; }
public Nullable<int> Parent { get; set; }
public int Level { get; set; }
public string ShortName { get; set; }
public string LongName { get; set; }
public bool IsActive { get; set; }

The Office table has an identity ID which we don't set. So.. EF uses 0. Well, we have an ID=0 record in the Office table (root office for us in this recursive self-reference table).

To resolve this, we set the Identity ID to -1. So no more conflict in an existing key. The -1 is ultimately ignored and the identity is set.

Adding: newOffice.ID = -1; did the trick.

Answer 8

I created a sample project that simulates the error when you have two relations. Basically the idea is that you have a customer with a list of orders. Then on the customer you want to store an additional property to mark the current order. This leads to "two" relations which the entity framework has issues on storing and deleting in one transactions.

It's better to create a bool flag "IsCurrent" on the orders and filter for that. Its also possible to create a Property or Extension on the Customer that does the filtering automatically. This was already explained in this post.

I think there is no other way except using two calls to SaveChanges which is bad because you then throw away the UnitOfWork idea.

Answer 9

Probably late but I had the same problem and solved it as this. in case there is a parent, add the child to parent children property, if not just save the object.

            using (var context = new MyEntities())
            {
                child.CreatedOn = DateTime.Now;

                if (child.ParentId == null)
                {
                    context.Things.Add(child);
                }
                else
                {
                    var parent = context.Things.Where(x => x.Id == child.ParentId).SingleOrDefault();

                    if(parent == null)
                    {
                        return false;
                    }

                    parent.Things.Add(child);
                }

                context.SaveChanges();

                return true;
            }

Answer 10

So I ran into this problem and I want to share the way I solved it, it is not as simple as calling saving changes twice, but it has some advantages over that method.

I had a situation where I wanted all the records to either succeed or fail, partial inserts of the children were not acceptable. I also didn't want to write code to delete the parent, if the child fails (what if there was a bug in that code, what if that code failed, etc.).

Secondly, it was possible to have a group of records, and I wanted all those records to succeed or fail in one transaction. Essentially, I got very specific with EF (my EF version is 6.1.3). Also I was only going one level deep in the parent child relationship, not an arbitrary number of levels deep.

int tempId = -1;
int parentTempId = -1;
foreach(var record in recordsToSave)
{
    var childRecords = record.ChildRecords.ToList();

    record.ChildRecords.Clear();

    record.RecId = tempId;
    parentTempId = tempId;
    tempId--;

    _db.Records.Add(record);

    foreach(var childRecord in childRecords)
    {
        childRecord.RecId = tempId;
        childRecord.ParentRecId = parentTempId;
        tempId--;
        _db.Records.Add(childRecord);
    }
}

using (TransactionScope tran = new TransactionScope())
{
    _db.SaveChanges();
    tran.Complete();
}

• First I cleared the child collection and copied it over to a temporary list. EF was having problems with my relationship.
• I created a temporary id and assigned it to the parent record, and stored that for later use with the children.
• I manually connected the child to the parent - via my temp ids.

It worked and it also insert my data, in a visually appealing way (at least for me)

Answer 11

In my case this error was producing because of deleting table that have circular reference between them. like database does not allow me to delete the page row as it has a reference in book table against bookmarked page. Also have reproduced this scenario here.

public class Book
{
   public int Id { get; set; }
   public int Name { get; set; }

   [ForeignKey("BookMarkedPage")]
   public int BookMarkedPageId { get; set; }
   public Page BookMarkedPage { get; set; }
}

public class Page
{
        public int Id { get; set; }

        [ForeignKey("Book")]
        public int BookId { get; set; }
        public Book Book { get; set; }
}

Resolution

There are two possible alternative to resolve this error

1. Before deleting a page record from page table, first remove bookmarked page reference from book table and then try to delete page row

2. Or instead of creating a circular reference create a bit in page table as isbookMarkedPage to identity the book marked page of a book

public class Book
{
   public int Id { get; set; }
   public int Name { get; set; }
}

public class Page
{
        public int Id { get; set; }

        [ForeignKey("Book")]
        public int BookId { get; set; }
        public Book Book { get; set; }

        public bool IsBookMarkedPage
}

Answer 12

I fixed this error , I have a self relation which pass with 0 as value instead of null so I fixed this by pass it a null and it worked with me