What is wrong on this CHART script? PLEASE!!!

Question

I got this error:
Error: Unable to describe SQL statement. Please correct it (WWV-13010)(WWV-)Critical Error in wwerr_api_error.get_errors! SQL Error Message: ORA-06502: PL/SQL: numeric or value error: character string buffer too small
ORA-06502: PL/SQL: numeric or value error (WWV-11230)
from this script:
select null the_link
, substr(location_name,5,1)
, count(((select count(*) from (SELECT exit.time, exit.location_name
FROM FlightTimes entry, FlightTimes exit
WHERE exit.flight_id = entry.flight_id
AND exit.location_name = entry.location_name
AND entry.time_type = 'ACTUAL'
AND entry.location_type = 'CTA'
AND entry.event = 'ENTRY'
AND (substr(entry.location_name,5,1) = :v_sector OR :v_sector = '%')
AND entry.time < to_date(:v_startdate,'DD-MM-YYYY HH24:MI')
AND (to_char(entry.time,'DAY')) IN :v_day
AND ((to_char(entry.time,'HH24')) >= :v_starthour or :v_starthour = '%')
AND ((to_char(entry.time,'HH24')) < :v_endhour or :v_endhour = '%')
AND exit.time_type = 'ACTUAL'
AND exit.location_type = 'CTA'
AND exit.event = 'EXIT'
AND (substr(entry.location_name,5,1) = :v_sector or :v_sector = '%')
AND (to_char(exit.time,'DAY')) IN :v_day
AND ((to_char(exit.time,'HH24')) >= :v_starthour or :v_starthour = '%')
AND ((to_Long postings are being truncated to ~1 kB at this time.

Answer 1

Try to give alias name for each column in the select like
the following
select null the_link
, substr(location_name,5,1) loc_name
, count(expression) cnt
-Krishnamurthy