How to throw SqlException when you need it in Test

You can do this with reflection, you will have to maintain it when Microsoft make changes, but it does work I just tested:

      internal class SqlExceptionTestHelper 
      {
         public static T Construct<T>(params object[] p)
         {
            return (T)typeof(T).GetConstructors(BindingFlags.NonPublic | BindingFlags.Instance)[0].Invoke(p);
         }

         public static SqlException GenerateSqlException()
         {

            SqlErrorCollection collection = Construct<SqlErrorCollection>();
　　　　　　　//2627 means error number
            SqlError error = Construct<SqlError>(2627, (byte)2, (byte)3, "server name", "error message", "proc", 100);

            typeof(SqlErrorCollection)
                .GetMethod("Add", BindingFlags.NonPublic | BindingFlags.Instance)
                .Invoke(collection, new object[] { error });


            var e = typeof(SqlException)
                .GetMethod("CreateException", BindingFlags.NonPublic | BindingFlags.Static)
                .Invoke(null, new object[] { collection, "7.0.0" }) as SqlException;

            return e;
         }

And then, the code about throw SqlException is like this:

"throw SqlExceptionTestHelper.GenerateSqlException()"

参考：http://stackoverflow.com/questions/1386962/how-to-throw-a-sqlexceptionneed-for-mocking  

How to throw a SqlException(need for mocking)

 

 

Unit Testing with SqlException in .NET: Only with help from Reflection

http://pietschsoft.com/post/2012/03/02/Unit-Testing-with-SqlException-in-NET-Only-with-help-from-Reflection