php - Update query for two different Column in two different table-MySQL -

i working on upwork type project , want create update query bids. user has free bids (which gets default per month) , pro bids can buy amount.
if apply on job want update -1 job_quota (if not 0 already), -1 pro bids in ascending order.

my table structure (in user table):

users

job_quota -------->id  12---------------->53 

buy_bids

id---->no_bids--->amount_paid--->user_id   1-----> 20------------>20---------------> 53  2-----> 20------------>20---------------> 53  3-----> 20------------>20---------------> 53 

i have idea - not how implement mysql query:

$query=<<< sql update users set job_quota=job_quota-1 if ( job_quota !=0 ) else update buy_bids set no_bids =no_bids-1 user_id=53 sql; 

can suggest me how can achieve it, not looking accurate solution need , suggestion should try achieve this.

many thanks.

something this?

update users ,buy_bids  set users.job_quota = case when users.job_quota !=0                                  users.job_quota-1                       else users.job_quota end,     buy_bids.no_bids =case when users.job_quota =0                                   buy_bids.no_bids-1                      else buy_bids.no_bids end users.user_id=buy_bids.user_id         , users.user_id=53; 

this not tested. suggestion. i'm not sure else condition,so added users.job_quota =0 . change accordingly.