Question

So I have this data structure

ID  DATE1     STATUS1 DATE2    STATUS2
1   1/1/2012  1       1/1/2012 3
1   3/1/2012  1       1/2/2012 3 
2   2/1/2012  1       3/4/2012 3
3   4/1/2012  1       NULL     3
4   2/1/2012  1       6/2/2012 3

How would I get to…

ID  DATE      STATUS
1   1/1/2012  1
1   1/1/2012  3
1   3/1/2012  1       
1   1/2/2012  3
2   2/1/2012  1       
2   3/4/2012  3
3   4/1/2012  1       
3   NULL      3
4   2/1/2012  1       
4   6/2/2012  3

My initial guess might be to use lots of unioned unpivots?

Answer 1

You can use union for this:

select id, date1 mydate, status1 status
from mytable
union all
select id, date2 mydate, status2 status
from mytable

if you want to remove dupes, just replace union all with union

Note: I’ve named the resulting date column mydate because date is probably a reserved keyword in whichever dbms you’re using..