LISTING 2: Creating the complex_valid Rule and Binding It to the Complex Type

CREATE rule complex_valid
AS
  -- Check whether last character is 'i'.
  RIGHT(RTRIM(@cx), 1) = 'i' AND
  IsNumeric(LEFT(LTRIM(@cx),
              PATINDEX('%_[-+]%', LTRIM(@cx)))) = 1 AND
  IsNumeric(SUBSTRING(LTRIM(@cx),
              PATINDEX('%_[-+]%', LTRIM(@cx)) + 1,
              LEN(RTRIM(LTRIM(@cx))) -
                PATINDEX('%_[-+]%', LTRIM(@cx)) - 1)) = 1
GO
EXEC sp_bindrule 'complex_valid', 'complex'
GO