How to get relationship id in views drupal 7?
If you want to output a link in views which leads to the page where the user's account can be deleted you can use the field "User: Cancel link". That field should be present in your view since you have the user as a relationship.



If you still want the user's uid and link to some page on your own you need to add the field called "User: uid" and then rewrite the output of the field.

Add the field called User: uid, then under the settings for the field expand Rewrite results and click Rewrite the output of this field, enter the text that should be displayed. Then click output this field as a link and use the [uid] placeholder in the link. The [uid] will be replaced with the user's uid when the View is rendered. You can see an example of the settings in the image below.