oracle 行列转换

1 select t.index_id,
2        MAX(decode(t.key, 'key', t.value, null)) as fee_code,
3        MAX(decode(t.key, 'value', t.value, null)) as reduction_fee,
4        MAX(decode(t.key, 'devalue', t.value, null)) as overdue_payperiod
5   from LA_T_REDUCTION_REGULAR t
6  where t.contract_id = '20171205D0904J9C0_18'
7  group by t.index_id
8  order by t.index_id

 1 SELECT t.index_id,
 2        MAX(CASE
 3              WHEN t.key = 'key' THEN
 4               t.value
 5              ELSE
 6               null
 7            END) fee_code,
 8        MAX(CASE
 9              WHEN t.key = 'value' THEN
10               t.value
11              ELSE
12               null
13            END) reduction_fee,
14        MAX(CASE
15              WHEN t.key = 'devalue' THEN
16               t.value
17              ELSE
18               null
19            END) overdue_payperiod
20   FROM LA_T_REDUCTION_REGULAR t
21  where t.contract_id = '20171205D0904J9C0_18'
22  GROUP BY t.index_id
23  order by t.index_id