Question

I have a problem that is quite simple to understand, but for me it is not that simple to implement.

I have a table named Time:

-----------------------------------
 DAY     TIME1     TIME2
-----------------------------------
 1       08.00     09.40
 1       09.40     10.00
 1       10.00     11.40
 2       08.00     08.50
 2       08.50     10.40
 ----------------------------------

What I want to get is like:

-------------------
 DAY     TIME     
-------------------
 1       08.00     
 1       09.40     
 1       10.00     
 1       11.00     
 2       08.00     
 2       08.50     
 2       10.40     
 ------------------

I have tried this code:

SELECT DISTINCT sub.val FROM (
  SELECT Time1 AS val FROM Time
  UNION ALL
  SELECT Time2 AS val FROM Time
) AS sub

And it is only return the Time column. I have no idea about joining the “Day” column. While I am trying to add the “Day” after the “DISTINCT sub.val”, it got error. How to do it?

Thank you very much.

Answer 1

select distinct day, time1 from mytab
union
select distinct day, time2 from mytab