Counting coupon usage

Hello.

In my application I have 3 entities:

• User
• Tag
• Coupon

A user may "subscribe" to many tags and a coupon may have many tags. The user receives coupons based on his tag subscription. The tables to do so are:

• users
• tags
• tag_user
• coupon_tag

Everything works just fine. Now I want to count how many times a coupon was viewed but also limit it per user. So if user John accesses coupon #105 4 times, the coupon will show that it was consumed only once (as there was only 1 user viewing it).

Currently I have in my coupons table a consumed property which is an unsigned integer.

Do you think the only way I can limit the consumption of the coupon to be unique per user is to add another table consumed_coupons with user_id and coupon_id? Now I can remove the consumed property on the coupons table and when I need the count for the coupon I can just run a count() query based on the coupon_id.