Perform INSERT with SELECT to insert multiple records

Question

In the diagram below there is a 1:1 relationship between \'DodgyOldTable\' and \'MainTable\'. Table \'Option\' contains records with \'OptionVal1\', \'OptionVal2\' and \'OptionV

Answer 1

What about CROSS JOIN solution?

DECLARE @DodgyOldTable TABLE (ID INT, OptionVal1 CHAR, OptionVal2 CHAR, 
  OptionVal3 CHAR)
INSERT INTO @DodgyOldTable
SELECT 1, 'y', 'n', 'y' UNION
SELECT 2, 'y', 'n', 'n' UNION
SELECT 3, 'n', 'n', 'y' UNION
SELECT 4, 'y', 'y', 'y' UNION
SELECT 5, 'n', 'n', 'n'

DECLARE @Option TABLE (OptionID INT, OptionDesc VARCHAR(100))
INSERT INTO @Option
SELECT 1, 'OptionVal1' UNION
SELECT 2, 'OptionVal2' UNION
SELECT 3, 'OptionVal3'

SELECT ID, OptionID FROM
(
    SELECT 
        ID, 
        CASE    
          WHEN (OptionVal1 = 'y' AND OptionDesc = 'OptionVal1') 
            OR (OptionVal2 = 'y' AND OptionDesc = 'OptionVal2') 
            OR (OptionVal3 = 'y' AND OptionDesc = 'OptionVal3')
          THEN OptionID 
          ELSE NULL 
        END AS OptionID 
    FROM @DodgyOldTable DOT CROSS JOIN @Option O 
)CRS
WHERE OptionID IS NOT NULL