public void TestDoubleFormat()
        {
            double?d;
            string v;

            d = null;
            v = SqlFormat.DoubleFormat(d);
            AssertAreEqual(v, "NULL", "Double? null");

            d = 6.4;
            v = SqlFormat.DoubleFormat(d);
            AssertAreEqual(v, "6.4", "Double 6,4");

            v = SqlFormat.DoubleFormat(double.MinValue, false);
            AssertAreEqual(v, "0", "Double min non null");

            v = SqlFormat.DoubleFormat(double.MaxValue, false);
            AssertAreEqual(v, "0", "Double min non null");

            v = SqlFormat.DoubleFormat(double.MinValue, true);
            AssertAreEqual(v, "NULL", "Double min null");
        }