Cannot add an entity with a key that is already in use (LINQ)

Question

I get this error Cannot add an entity with a key that is already in use. when I run the code below.

Tables: enter image description here

What am i missing?

    private void CopyAllPageObjects(int fromPageID, int toPageID)
    {
        CMSDataContext _db = new CMSDataContext();

        // Copy page objects
        var originalPageObjects = (from x in _db.CMSPageObjects
                                   where x.PageID == fromPageID
                                   select x);

        List<CMSPageObject> newPageObjects = new List<CMSPageObject>();
        foreach (CMSPageObject po in originalPageObjects)
        {
            CMSPageObject newPageObject = new CMSPageObject();
            newPageObject.PageID = toPageID;
            newPageObject.CMSObjectID = po.CMSObjectID;
            newPageObject.Name = po.Name;
            newPageObject.Sorting = po.Sorting;
            newPageObjects.Add(newPageObject);

            // Copy page object attribute values
            var originalPoavs = (from x in _db.CMSPageObjectAttributeValues
                                 where x.CMSPageObjectID == po.ID
                                 select x);

            List<CMSPageObjectAttributeValue> newPoavs = new List<CMSPageObjectAttributeValue>();
            foreach (CMSPageObjectAttributeValue poav in originalPoavs)
            {
                CMSPageObjectAttributeValue newPoav = new CMSPageObjectAttributeValue();
                newPoav.CMSAttributeID = poav.CMSAttributeID;
                newPoav.CMSPageObjectID = newPageObject.ID;
                newPoav.LCID = poav.LCID;
                newPoav.Value = poav.Value;
                newPoavs.Add(newPoav);
            }
            _db.CMSPageObjectAttributeValues.InsertAllOnSubmit(newPoavs);
        }

        _db.CMSPageObjects.InsertAllOnSubmit(newPageObjects);
        _db.SubmitChanges();
    }

I guess `newPoav.CMSPageObjectID = newPageObject.ID;` throws the error. — Martin at Mennt, Mar 13 '12 at 09:37
I have removed all code from `// Copy page object attribute values` to `_db.CMSPageObjectAttributeValues.InsertAllOnSubmit(newPoavs);` and that is working as it should. So guess it is something inside that code that is messed up. — Martin at Mennt, Mar 13 '12 at 09:50
cant you debug and see where exactly in code you getting error? — Renatas M., Mar 13 '12 at 09:54
`newPageObject.ID` is set before setting to `newPoav.CMSPageObjectID`? — Renatas M., Mar 13 '12 at 10:05

score 4 · Answer 1 · answered Mar 13 '12 at 09:39

4

I was getting this error and it was because I had forgotten to set the Primary Key field in the database to "Identity Specification" (auto-increment). But that is just a guess

answered Mar 13 '12 at 09:39

Arion

31,011
10
70
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Arek · Accepted Answer · 2012-03-13T09:49:02.257

It looks like you're trying to add an object, while another one with same primary key exists. Are PageID or CMSObjectID primary keys? Or CMSAttributeID?

You might also want to share more data about how your data tables look like.

Update: after you added database struct, I would look closer at this line:

newPoav.CMSPageObjectID = newPageObject.ID;

the newPageObject.ID is probably not known at this time, because you didn't add the object to the DB yet (I suspect ID is identity). I think you could use:

newPoav.CMSPageObject = newPageObject

score 2 · Answer 3 · answered Mar 13 '12 at 09:37

2

Seems you are missing primary key or an unique key on CMSPageObject table. Please try to verify the keys in the database. I had same issue since I had missed the PK on the table.

Cheers.

answered Mar 13 '12 at 09:37

Shailesh

1,178
11
12

score 0 · Answer 4 · answered Mar 13 '12 at 10:06

you have to add some code just for testing if the list newPoavs have a key exist already in the database

you can just add this

        foreach (CMSPageObjectAttributeValue poav in originalPoavs)
        {
            CMSPageObjectAttributeValue newPoav = new CMSPageObjectAttributeValue();
            newPoav.CMSAttributeID = poav.CMSAttributeID;
            newPoav.CMSPageObjectID = newPageObject.ID;
            newPoav.LCID = poav.LCID;
            newPoav.Value = poav.Value;
            newPoavs.Add(newPoav);
            if(_db.CMSPageObjectAttributeValues.Any(x=>x.LCID == newPoav.LCID & x.CMSAttributeID == newPoav.CMSAttributeID & x.CMSPageObjectID == newPoav.CMSPageObjectID ))
            MessageBox.Show("Already exist");
        }

just to test your values

Cannot add an entity with a key that is already in use (LINQ)

4 Answers4

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