Question

Some easy points for somebody here, take the following table of data:

EventCode  ProcessId
---------- ---------
2          1
-6         3
42         1
-6         2
-12        2
23         4
4          2
-23        1
12         3
-26        1

I need a query that will get be a count of all Process ID where there is a negative event code. So from the dataset above the result would be 3 (Process ID’s 1,2 and 3 have negative event codes, process ID 4 does not)

Probably really simple, involving groups but I just can’t see the wood for the trees.

As a relevant aside, there are millions of rows in this table.

Answer 1

SELECT COUNT(DISTINCT ProcessID) FROM table
WHERE EventCode < 0