尝试子查询时出现 Ambiguous column name 错误

Question

The prompt is Assume Risk “1” facilities are required to have at least 3-type inspections per year. Display the facilities that failed to meet this requirement in 2013 AND that had at least 1 Failed Canvass-type inspection.Show the facility name and how many Canvass inspections it had in 2013. HINT: use a subquery

So this is my code

SELECT DBAName, COUNT(*)
FROM FoodInspectionOriginal, Organization
WHERE Risk = 1 AND [Inspection Type] IN (SELECT [Inspection Type] FROM FoodInspectionOriginal WHERE [Inspection Type] = 'Canvass' AND [Inspection Date] = Year(2013))
GROUP BY DBAName;

And I am getting this is the output

Msg 209, Level 16, State 1, Line 3

Ambiguous column name 'Risk'.

Answer 1

I would just use aggregation. Assuming the following table structure for table foodinspectionoriginal :

dbaname           -- name of the facility
inspection_date   
inspection_type   -- "Canvass", ...
inspection_status -- "successful", "failed"

The query could be phrased as follows:

select dbaname,
    sum(case when inspection_type = 'Canvass' and inspection_status = 'failed' then 1 else 0 end) as cnt_failed_canvass
from foodinspectionoriginal
where 
    risk = 1 
    and inspection_date >= '20130101' 
    and inspection_date <  '20140101'
group by dbaname 
having 
    count(*) < 3 
    and sum(case when inspection_type = 'Canvass' and inspection_status = 'failed' then 1 else 0 end) > 0