Need help with division within a query

Question

Hello all~
I am trying to divide these two columns to get a % of case numbers involving an accident. Im pretty sure you need to use decode to avoid the divide by 0 error but not sure how to implement this within my query. When i run this query below, it gives me the result of "1", which is not correct. Can someone help me please?
Oracle Version 10g
ACCIDENT is a datatype VARCHAR
CASE_NUMBER is a datatype VARCHAR
select to_char(count(ACCIDENT),'999,999,999') as "ACCIDENT",
to_char(COUNT(CASE_NUMBER),'999,999,999')as "CASE NUMBER",
round(ratio_to_report(count(accident))
OVER()*100,2)as "%"
from      "PURSUIT"
WHERE ACCIDENT = 'Y'
AND
(:P1_BEG_DATE IS NULL AND :P1_END_DATE IS NULL
OR
pursuit_date BETWEEN to_date(:p1_beg_date,'MM/DD/YYYY') and to_date
(:p1_end_date,'MM/DD/YYYY'))
AND(:P1_TROOP=pursuit.officer_troop OR :p1_troop IS NULL) 
AND(:P1_RADIO=pursuit.officer_radio OR :p1_radio IS NULL)
group by case_numberThanks
Deanna

Answer 1

Are you sure that the ANDs and ORs in your WHERE clause will take precedence properly?
Also, if you always select only cases where there has been an accident, what percentage would you like to display? Surely in this case the percentage of cases involving in accident in cases where there was an accident.. is 100%?
as a simpler example
SELECT
  accident,
  ROUND(RATIO_TO_REPORT(count(*)) OVER() * 100)
FROM
  pursuit
GROUP BY
  accidentHere's a trick to neaten up those IS NULLs:
SELECT
  accident,
  ROUND(RATIO_TO_REPORT(count(*)) OVER() * 100)
FROM
  pursuit
WHERE
  pursuit_date >= COALESCE(:p1_beg_date, pursuit_date) AND
  pursuit_date <= COALESCE(:p1_end_date, pursuit_date) AND
  officer_troop LIKE :p1_troop AND
  offcier_radio LIKE :p1_radio
GROUP BY
  accidentTo wildcard a date, simply pass NULL in; the coalesce will replace the null with the pursuit_date from the record (thus the >= and <= becomes true)
To wildcard the troop or the radio, simply pass a '%' symbol as the value of the parameter. If the front end code is already set up to pass nulls, use the COALESCE trick above