Question

I am getting this error message when using EF 4.1 code first approach with Sql compact 4. I don’t see any model who has id column more than one so i have no idea why this error occured. What can cause this error ?

Edit : I want to specifiy few extra things. Database creating is success but model creating is not. And Exception has been thrown from sqlce methods.

Answer 1

This issue stems from a SQL query that returns two or more columns that have an identical name. SQL will handle exact duplicate names on columns with no problem but c# will puke errors all over like this one.

example situation:

TableA
  int Id
  varchar Name

TableB
  int Id
  int A_Id
  varchar Name


SELECT A.*,
       B.Name
FROM TableA A

INNER JOIN TableB 
   ON B.A_Id = A.Id

The Id and Name columns would be duplicated and cause an exception with EF