Question

I have a question, although I can’t really go into specifics.

Will the following query:

SELECT DISTINCT tableOuter.Property, (SELECT COUNT(ID) FROM table AS tableInner WHERE tableInner.Property = tableOuter.Property)
FROM table AS tableOuter
WHERE tableOuter.DateTime > DATEADD(year, -1, GETDATE())
  AND tableOuter.Property IN (
   ...
)

Select one instance of each property in the IN clause, together with how often a row with that property occured in the last year?

I just read up on Correlated Subqueries on MSDN, but am not sure if I got it right.

Answer 1

If i understand you corrrecly, you want to get all occurences of each Property in the last year, am i right?

Then use GROUP BY with a HAVING clause:

SELECT tableOuter.Property, COUNT(*) AS Count
FROM table AS tableOuter
GROUP BY tableOuter.Property
HAVING tableOuter.DateTime > DATEADD(year, -1, GETDATE())
AND tableOuter.Property IN ( .... )