其實列轉行是比較簡單的用sum和decode函數就可以了，但是我遇到的項目，不知道數據誰設計的居然字段裏面還設計成long類型，此long類型與java中的不同，oracle中的long是指可變長二進制數據，最長2G，哎沒辦法只好轉換了。
以下是hsqldb的轉換，用到了轉換函數convert，可以將long類型的轉換爲double類型，其中d.value是long類型，status是int類型，所以value需要轉換
SELECT P.NAME,P.ID,
SUM(DECODE(D.K_NAME,'a',convert(d.value,SQL_DOUBLE),NULL)) AS a1,
SUM(DECODE(D.K_NAME,'a',convert(d.value,SQL_DOUBLE),NULL)) AS b1,
SUM(DECODE(D.K_NAME,'a',D.STATUS,NULL)) AS a1_status,
SUM(DECODE(D.K_NAME,'a',D.STATUS,NULL)) AS b1_status
FROM
P LEFT JOIN
D ON P.ID=D.id
WHERE a IN ('a','b')
GROUP BY P.NAME,P.ID
ORDER BY decode(a,null,0,a) DESC LIMIT 0,10
h2是內存數據庫，跟hsqldb類似，但是性能好像沒有hsqldb穩定
SELECT P.NAME,P.ID,
SUM(DECODE(D.K_NAME,'a',convert(d.value,number),NULL)) AS a1,
SUM(DECODE(D.K_NAME,'a',convert(d.value,number),NULL)) AS b1,
SUM(DECODE(D.K_NAME,'a',D.STATUS,NULL)) AS a1_status,
SUM(DECODE(D.K_NAME,'a',D.STATUS,NULL)) AS b1_status
FROM
P LEFT JOIN
D ON P.ID=D.id
WHERE a IN ('a','b')
GROUP BY P.NAME,P.ID
ORDER BY decode(a,null,0,a) DESC LIMIT 0,10