SQL计数记录，值为0

Question

I'm using a SQL query for an app, but I cant get it to count values with 0 results.

The code is shown below:

select CarrierPosition, COUNT(*) as FailCount
from tbl_0000000024,
     tbl_0000000025
where asictestdate >= DATEADD(hour,-6, getdate())
  and FK_AS0000000032 = fk_as0000000056
  and fk_as0000000046 = '135'
  and FailReason = '151'
  and tbl_0000000025.Status = ' Current'
group by CarrierPosition
Order by CarrierPosition

It should show up a fail count for 8 positions, but leaves out positions 1 and 4 as they have a FailCount of 0. How do I get it to show the other 2 rows?

Thanks

Answer 1

Do a LEFT JOIN , modern explicit syntax, to get those rows too.

select CarrierPosition, COUNT(*) as FailCount
from tbl_0000000024
LEFT JOIN tbl_0000000025 ON FK_AS0000000032 = fk_as0000000056
where asictestdate >= DATEADD(hour,-6, getdate())
  and fk_as0000000046 = '135'
  and FailReason = '151'
  and tbl_0000000025.Status = ' Current'
group by CarrierPosition
Order by CarrierPosition

(Perhaps it should be the other way, the column and table names don't describe very well. Switch LEFT to RIGHT and see what happens if the above query doesn't work as expected.)