在MS Access查询中返回没有结果的值

Question

I have an MS Access 2013 query that runs automatically and shows the number of times certain incidents happen in each county.

The problem is that a few of the counties normally don't have any of these incidents so the query only shows counties with incidents.

I need to have the report list all counties even if the value is 0 . I know I'm missing something simple here, but I can't figure it out and all my research to find an answer has left me without an answer.

I inherited this database, so it's not optimally designed. I'm also newer to access databases.

I have checked all the options for the query in the design and SQL view (maybe I'm missing it.)

Here is the entire code for the query:

SELECT [FOCUS-CGDataComplete_By_Month/Year].COUNTY, Count([FOCUS- 
CGDataComplete_By_Month/Year].COUNTY) AS CT
FROM [FOCUS-CGDataComplete_By_Month/Year]
GROUP BY [FOCUS-CGDataComplete_By_Month/Year].COUNTY
ORDER BY Count([FOCUS-CGDataComplete_By_Month/Year].COUNTY) DESC;

The query runs correctly and returns all counties with incidents properly. So counties with incidents have the correct number, but counties with no incidents do not show (I know this is expected, but how do I 'override' that?)

Answer 1

Firstly, you'll need a table containing all possible counties that you wish to see in the output - if there are counties which don't appear in any record in the table [FOCUS-CGDataComplete_By_Month/Year] , then this table obviously cannot report on counties of which it has no knowledge.

Equipped with a table containing all possible counties, you can use a left join to output all counties in this table, alongside the count of records which appear in your [FOCUS-CGDataComplete_By_Month/Year] table associated with each county.

Such a query could be something along the lines of the following:

select c.county, count(f.county) as ct
from countytable c left join [focus-cgdatacomplete_by_month/year] f on c.county = f.county
group by c.county
order by count(f.county) desc

Here, I assume that countytable is a table containing all possible values for the county field - you should rename this to suit the name of this table in your database.