You have a count of 1 for each of the IDs on the EVENT_ID column. That's correct, each different ID is counted only once.
If you remove the column EVENT_ID, you will just have the total count of distinct event ids.
You have a count of 1 for each of the IDs on the EVENT_ID column. That's correct, each different ID is counted only once.
If you remove the column EVENT_ID, you will just have the total count of distinct event ids.