SubmitChanges throws IndexOutOfRangeException

August 25th, 2008

Here’s hoping that this will help someone else.  I’ve been working on a project for the past few months using LINQ to SQL vs. a Legacy database (and I do mean “vs.”). Today I ran into updates on a particular table throwing IndexOutOfRangeExceptions.

All you’re trying to do is update some instance generated from  a LTS table.  Instead, you get an IndexOutOfRangeException from deep within Linq, particularly “System.Data.Linq.IdentityManager.StandardIdentityManager“. 

Here’s what the context looks like:

image

“Views” is a table that maps SomeTypeID and SomeValueID into a ViewID.  (The table isn’t actually named ‘Views,’ but the purpose is the same)  This ViewID is instrumental in working with “Elements,” and we’re trying to change the values of a particular Element and put it back into the database.

Some code:

var ctx = new ExampleDataContext();
// get some element:
var element = ctx.Elements.Where(e => e.ElementID == 1).First();
// set some property:
element.SomeOtherValue = false;
// attempt to save -- FAIL
ctx.SubmitChanges();

No Big Deal, right?  However executing this results in:

“System.IndexOutOfRangeException was unhandled
  Message=”Index was outside the bounds of the array.”
  Source=”System.Data.Linq”
  StackTrace:
       at System.Data.Linq.IdentityManager.StandardIdentityManager.MultiKeyManager`3.TryCreateKeyFromValues(Object[] values, MultiKey`2& k)”  (etc etc etc)

 

The Solution:  I mentioned this was “legacy” database, right?  Take a look at the Views table again.  The database has SomeTypeID and SomeValueID as the primary keys of the table, but we’re treating ViewID as if it were a primary key – and apparently that’s what Linq to SQL doesn’t like.

So, changing the legacy database is out of the question for this particular project, however I can tell the Context how I want things to behave:

image

Remove the PrimaryKey=true attributes from SomeType and SomeValue, and add that on the ViewID property, and now LinqToSql handles the association correctly.

Tony Rasa

  • Naveen

    Hello,
    Thanks a lot, I hit the same problem and without this solution would have taken a lot of time to figure out the fix.

  • Abel

    This is a seriously great post. My expletive count was already creeping towards triple digits and this post saved the day.

  • http://instantdevelopment.blogspot.com/ Liam

    Really well explained post. I have had this problem several times and resolved it just as you have. It is a pity that you have to change the Linq model, which means that you have to remember to do it again if you regenerate the affected tables.

  • Joe

    Yea, that saved me. Thanks a lot. I had an old primary key on a related table which was wrong. You rock.

  • Lasse

    I had the same exception, but the above didn’t really help me. I had a function that did something very similar to your above code – and this function worked in some cases, but threw the IndexOutOfRangeException in others. I ended up using this approach instead:

    db.ExecuteCommand(“UPDATE TableName SET FieldName= @p0 WHERE IDField = @p1″, FldVal, ID);

    Not quite as elegant, but it works.

  • Vien Tri

    I also have the same problem. but i don’t have two colum as the primary keys. I don’t have solution for this problem. please help me.

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