PHP - Oracle正则表达式[关闭]

I build formula for Oracle execute. But I not good regular.

(CLICK/10)/IMPRESSION => DECODE(IMPRESSION,0,0,(CLICK/10)/IMPRESSION)


RESPONSE/REQUEST    =>  DECODE(REQUEST,0,0,RESPONSE/REQUEST)


CLICK/REQUEST/IMPRESSION = DECODE(IMPRESSION,0,0,DECODE(REQUEST,0,0,CLICK/REQUEST)/IMPRESSION)

Please help me 1 solution or 1 pattern for PHP.

I would like to do it using CASE..WHEN..END as it is more readable and easy to debug.

See Your answer and my answer as following:

(CLICK/10)/IMPRESSION 
Your method => DECODE(IMPRESSION,0,0,(CLICK/10)/IMPRESSION)
My Method => (CLICK/10)/(CASE WHEN IMPRESSION = 0 THEN 1 ELSE IMPRESSION END)

RESPONSE/REQUEST    
Your method =>  DECODE(REQUEST,0,0,RESPONSE/REQUEST)
My Method => RESPONSE/(CASE WHEN REQUEST = 0 THEN 1 ELSE REQUEST END)


CLICK/REQUEST/IMPRESSION 
Your method => DECODE(IMPRESSION,0,0,DECODE(REQUEST,0,0,CLICK/REQUEST)/IMPRESSION)
My Method => CLICK/(CASE WHEN REQUEST = 0 THEN 1 ELSE REQUEST END)/(CASE WHEN IMPRESSION = 0 THEN 1 ELSE IMPRESSION END)

Cheers!!