sql - MySQL - How to get a 0 when COUNT(*) returns null? -


i'm haing difficulties sql request. in request, wanna get, week (entered in parameter), , year (also in parameter) number of opened tickets tech. goal kind of table :

year    week tech_id   backlog_tickets 2017     1      5            11 2017     1      6             1 2017     1      6             0 

but problem that, when tech has no ticket in backlog (0), record not created, because count(*) returns null value.

so here have : year week tech_id backlog_tickets 2017 1 5 11 2017 1 6 1

and here request :

set @selecteddate = date_add(str_to_date('01-01-2017', '%d-%m-%y'), interval _week week);  insert whd_stats.backlog_tickets_by_tech_week (year, week, tech_id, backlog_tickets_number)     select _year 'year', _week 'week',      coalesce(j.assigned_tech_id , 99999) 'tech',      @backlognumber := count(j.job_ticket_id)     whd.job_ticket j     left outer join whd.tech t on j.assigned_tech_id = t.client_id     left outer join whd.status_type s on j.status_type_id = s.status_type_id      j.deleted = 0     -- create date given year, add number of week      , j.report_date <= @selecteddate      , (j.close_date > @selecteddate     or (j.close_date null , s.status_type_name in ('open', 'pending', 'approval pending')))     group year, week, tech on duplicate key update backlog_tickets_number = @backlognumber; 

i have tried replace count(j.job_ticket_id) ifnull(count(j.job_ticket_id), 0), tried coalesce(count(j.job_ticket_id), 0) none working, , have no more idea...

can please me?

thanks!

one option here "calendar table" approach. can create new table looking this:

tech_id 1 2 3 4 5 

you change query such begins calendar table , left joins outwards. guarantee every tech_id appear in result set, if absent in recorded data.


Comments

Popular posts from this blog

Is there a better way to structure post methods in Class Based Views -

performance - Why is XCHG reg, reg a 3 micro-op instruction on modern Intel architectures? -

jquery - Responsive Navbar with Sub Navbar -