So I have the task to create a DB model for a simple booking system and I have not clue so I ask for help here. What I have done until now is as image shows but I don't know if this is enough to build a simple booking system from scratch. I tried Google looking for some DB designs and find nothing helpful, any advice? What did yours think about my model? Something missing?

UPDATE (based on answers) Ups I forget to tell what the requirements are and here we go:

• sport_field can be booked for given hours and just in one day meaning for example users can't book a sport_field for two days or two and half a day but users can book for one, two, three and more hours. (hours is a valid period from 9:00 AM to 11:00PM hours outside this times isn't valid - maybe I'll hide using programming)

• there will be a wait list and what is this? A queue for sport_field based on availability (maybe I'm lost here too since this is the main behavior of booking systems)

• sport_field will remain booked for one day maximum so for example users can book the sport_field and administrators will wait for payment, if payment is not successfully then sport_field will be available once again during the next day.

• price is fixed for each sport_field it will never change and price is hourly

• active means to me if the sport_field is reserved for a period or specific hour, maybe my design is wrong and I'm unsure

• users table comes from another system I'm just adding the booking part to a huge system but I need to use their tables