經典SQL-1

wangkxxe發表於2009-07-21
SQL

不用函式實現N的階乘

SELECT MAX(prod)
FROM (SELECT prod
FROM ( SELECT ROWNUM rn
FROM DUAL
CONNECT BY ROWNUM<=6
)
MODEL RETURN UPDATED ROWS
DIMENSION BY (rn)
MEASURES (rn rn2,1 prod )
RULES (
prod[any] order by rn=DECODE(rn2[cv()],1,1,prod[cv()-1]*rn2[cv()])
)
)

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