mysql count records using datediff and where

[Pravesh_1]

I want to count records using datediff() and where condition; I am getting the result with no. of days; but cant count records with condition; below is the my query

SELECT DATEDIFF(CURDATE(), jobs.jobs_listed_date)
FROM tbl_first_category AS 
FIRST , tbl_second_category AS 
SECOND , tbl_jobs AS jobs
WHERE first.fc_id = second.sc_fc_id
AND second.sc_url =  'accountancy-bookkeeping'
AND jobs.jobs_category_id = second.sc_id
AND jobs.jobs_status =1
LIMIT 0 , 30

[urtrivedi]

what are sample records?
what output you expect from the query ?

[Pravesh_1]

I want to count records