Row not found or changed LINQ C# error on simple statement

Question

First of all, there is no chance that this is a multi-user issue, as I\'m working locally on a dev version of the database.

I am getting the not very explanatory R

Answer 1

Looking at the SQL Profiler output, it helped me figure out the answer to this. There was a bad piece of SQL being generated which ended with WHERE 0 = 1 ... an obvious error.

It turns out that the field had simply been changed to allow nulls by another developer, and the Linq-to-SQL file hadn't been updated accordingly.

In short, if the Row not found or changed error message appears to be generated for no reason, make sure your database schema exactly matches your .dbml file else you'll get this error message on any fields that have slightly differing schemas.

Answer 2

Take a look at the connection property "No Count" at sql server server level

1. Right click on Sql server connection in Object Explorer -->Property
2. Go to Connection Tab/Page
3. Look for the Default connection option "no count"
4. Make sure this option is not checked.

Answer 3

Another possibility that I've found to add to the excellent list of answers here:

When using a not-nullable column in a database - then mapping that to a datatype that is intrinsically nullable (in this example DB type is LONG BLOB NOT NULL mapped to a byte array in c#) you can end up in a situation where updating the database with the exact same byte array causes this error to be thrown.

Example: You have a website that allows the user to upload an image to the database. Your table has a blob (image in sql server, whatever) that is not nullable. The user chooses to update the record with the exact same image that is already there. The update check will fail. I fixed this by first doing a .SequenceEqual() check and then only calling .SubmitChanges() on the context object if the incoming byte array was not equal to the existing one.

Answer 4

I had this issue even when the database schema and dbml matched exactly. The issue was I was trying to change an entity and insert entities in a single SubmitChanges statement. I fixed it by doing SubmitChanges on each operation instead of all at once.

This was all in a transaction scope so that may have something to do with it but I'm not sure.