Creating a SQL Exception

When a SQL Exception is encountered in a function, it can be categorized based on the SQL Number. This is especially useful in scenarios like Unit Testing, where there might be a need to create a new SQL Exception for testing purposes.

//create the SQL Exception
    private SqlException MakeSqlException(int sqlNumber)
    {
        //create new exception
        var newException = new Exception();

        //construct the SQL Error Collection
        SqlErrorCollection collection = Construct<sqlerrorcollection(); construct="" a="" sql="" error="" with="" parameter="" (this="" case="" its="" number)="" sqlerror="">(sqlNumber, (byte)2, (byte)3, "server name", "error message", "proc", 100, newException);

        //Using reflection inject the error into the SqlErrorCollection
        typeof(SqlErrorCollection)
        .GetMethod("Add", BindingFlags.NonPublic |         
BindingFlags.Instance)
        .Invoke(collection, new object[] { error });

        //Using reflection create the SQL exception
        var e = typeof(SqlException)
        .GetMethod("CreateException", BindingFlags.NonPublic |
       BindingFlags.Static, null, CallingConventions.ExplicitThis, 
       new[] { typeof(SqlErrorCollection), typeof(string) }, new ParameterModifier[] { })
       .Invoke(null, new object[] { collection, "11.0.0" }) as SqlException;

        return e;
    }

    //constructs a class based off of the type and parameters
    private T Construct(params object[] p)
    {
        //declare a new var for type
        var t = new Type[p.Length];
        
        //for each parameter get the type
        for (var i = 0; i < p.Length; i++)
        {
            t[i] = p[i].GetType();
        }
        
        //get constructor info 
        var constructorInfo = typeof(T).GetConstructor(BindingFlags.NonPublic | BindingFlags.Instance, null, t, null);
        
        if (constructorInfo == null)
        {
            throw new InvalidOperationException(string.Format("Cannot find a matching private or static constructor for type {0} with the constructor parameters ({1})", typeof(T).Name, string.Join(", ", t)));
        }
        
        //invoke and return constructor
        return (T)constructorInfo.Invoke(p);
    }</sqlerrorcollection();>