Question

I have tables like this fake ones:

data:
    id  type    month   value
    1   1       1       10
    2   1       2       20
    3   1       3       30
    4   2       1       40
    5   2       2       50
    6   2       3       60
    7   3       1       70
    8   3       2       80
    9   3       3       90
    10  4       1       100
    11  4       2       110
    12  4       3       120

type:
    id  name
    1   A
    2   B
    3   C
    4   D

What I want:
    month   valueA  valueB  valueC  valueD
    1       10      40      70      100
    2       20      50      80      110
    3       30      60      90      120

How can I make this query?
I’m using Oracle 10g.

Answer 1

It looks like you want a relatively straightforward pivot of the data. If you were using 11g, you could use the more elegant PIVOT function. But in 10g, you could still do something like this

SQL> ed
Wrote file afiedt.buf

  1  with data as (
  2    select 1 id, 1 type, 1 month, 10 value from dual union all
  3    select 2,1,2,20 from dual union all
  4    select 3,1,3,30 from dual union all
  5    select 4,2,1,40 from dual union all
  6    select 5,2,2,50 from dual union all
  7    select 6,2,3,60 from dual union all
  8    select 7,3,1,70 from dual union all
  9    select 8,3,2,80 from dual union all
 10    select 9,3,3,90 from dual union all
 11    select 10,4,1,100 from dual union all
 12    select 11,4,2,110 from dual union all
 13    select 12,4,3,120 from dual
 14  ),
 15  type as (
 16    select 1 id, 'A' name from dual union all
 17    select 2,'B' from dual union all
 18    select 3,'C' from dual union all
 19    select 4,'D' from dual)
 20  select d.month,
 21         max(case when t.name = 'A' then d.value else null end) valueA,
 22         max(case when t.name = 'B' then d.value else null end) valueB,
 23         max(case when t.name = 'C' then d.value else null end) valueC,
 24         max(case when t.name = 'D' then d.value else null end) valueD
 25    from data d,
 26         type t
 27   where d.type = t.id
 28*  group by d.month
SQL> /

     MONTH     VALUEA     VALUEB     VALUEC     VALUED
---------- ---------- ---------- ---------- ----------
         1         10         40         70        100
         2         20         50         80        110
         3         30         60         90        120