How can I have more than zero Events, but zero Unique Events?

问题

I have a page which in generating Event Actions. They all belong to the same Category, and they have no labels.

When I look at my Events Overview, drill down to a specific Event Action, and then add a secondary dimension of Page, I get some events that have a positive number for Total Events, yet zero for Unique Events.

How can this be?

Sample table:

| Event Action | Page       | Total Events | Unique Events | Event Value |
|==============|============|==============|===============|=============|
| Opened table | /?uuid=123 |  21          |  3            | 0           |
| Opened table | /?uuid=234 |  6           |  0            | 0           |  <===

Here is a screenshot: https://imgur.com/a/v8rkj

Thoughts?

回答1:

The problem is that you are mixing an event hit scope metric with a page hit scope dimension, much like when you try reporting sessions for pages, the session count is associated with the first page viewed. A unique event is the first time an event with a specific category, action and label occurs in a session.

In this case (of your example), the unique event is also associated with the first page viewed. From the look of it, that event happened 21 times on your site, and 3 times it happened on the /?uuid=123 page first before it happened on the /?uuid=234 page (6 times). The 'unique' count gets associated with the first page that it occurred on, so the second page shows 0.

来源：https://stackoverflow.com/questions/49761948/how-can-i-have-more-than-zero-events-but-zero-unique-events