Question

I’m trying to combine multiple column values into 1 and then label them distinctly with a new column for a rollup table. Please see below for example.

Example:

(select
  id, size, size2
from
  table1
where
  date = curdate()
)a

union all

(select
  id, size, size2
from
  table2
where
  date = curdate()
)b

output:

ID size size2

1 23 47
2 25 33

How would I combine size and size2 into one column, and have another field that labels them?

Output would look like this:

ID values type

1 23 size

2 47 size2

3 25 size

4 33 size2

I’m thinking this should be some type of case statement, but I can’t seem to wrap my mind around it. Any ideas?

Answer 1

You could write a 4 part union. New ids are interleaved from table1/2.ids:

(SELECT id*2+0, size,  'size'  FROM table1 WHERE date = curdate())
UNION ALL
(SELECT id*2+0, size2, 'size2' FROM table1 WHERE date = curdate())
UNION ALL
(SELECT id*2+1, size,  'size'  FROM table2 WHERE date = curdate())
UNION ALL
(SELECT id*2+1, size2, 'size2' FROM table2 WHERE date = curdate())