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

You could UNION all of selects together to give one result set but it depends on your reasons for not wanting the multiple selects - if there are too many or the number of selects may change frequently it'll still be a pain to amend the query with the additional selects. Unfortunatly I think you will have to put the logic somewhere that determines which bit(s) of DodgyOldTable map to the new structure and either write a migration script (or SSIS package) to bulk migrate (if this is a one off job) or UNION your results together...

INSERT MainTable_Option ([MainTableID],[OptionID])
SELECT ID, (CASE WHEN OptionVal1 = 'y' THEN (SELECT OptionID FROM Option WHERE OptionDesc = 'OptionVal1') END
FROM DodgyOldTable
WHERE OptionVal1 = 'y
UNION
SELECT ID, (CASE WHEN OptionVal2 = 'y' THEN (SELECT OptionID FROM Option WHERE OptionDesc = 'OptionVal2') END
FROM DodgyOldTable
WHERE OptionVal2 = 'y
...