Question

my table looks like this:

+--------------------------+
| key | value-name | value |
+-----+------------+-------+
| 1   | color      | green |
| 1   | height     | 15    |
| 2   | whatever   | lol   |
+-----+------------+-------+

and i want to flip it so it looks like:

+-----+-------+--------+----------+
| key | color | height | whatever |
+-----+-------+--------+----------+
| 1   | green | 15     | ---      |
| 2   | ---   | ---    | lol      |
+-----+-------+--------+----------+

with sql like:

SELECT key AS k,
  (SELECT color FROM table WHERE key = k),
  (SELECT height FROM table WHERE key = k), ...

… and so on

How can ths be done without creating a subselect for every single value-name (because I believe this is not very fast) ?

My DBS is Oracle 10g.

Edit: I found some examples afterwards, but they all just join and I can’t do that because my table has many value-names.

Answer 1

select 
  key
, max( case value-name when 'color' then value else NULL end)      as color
, max( case value-name when 'heght' then value else NULL end)      as height
, max( case value-name when 'whatever' then value else NULL end)   as whatever
from 
  table
group by key