Question

I’m creating a page where I want users to be able to book a seat for an event.

---

• 1 user can only book 1 seat
• users have no seat selected upon login, first after buying into a spot
• Need to able to clear seats table, without loosing anything from user-table (except of course the assigned seats.)

---

I’ve created two tables, and since I’m pretty new to mySQL, I wanted to check if this was done correctly:

• members-table:
• user_id int(8) Not null auto_increment
• user_name varchar(30) Not null
• user_pass varchar(255) Not null
• seat_ID smallint(6) Yes NULL

---

• seats-table
• seat_ID smallint(6) No auto_increment
• user_id smallint(6) Yes NULL
• seat_status tinyint(4) Yes NULL
• seat_status tinyint(4) Yes NULL

---

I’ve created 2 FK-refs:

ALTER TABLE seats
ADD CONSTRAINT FK_seats  
FOREIGN KEY (user_id) REFERENCES members(user_id)  
ON UPDATE CASCADE  
ON DELETE CASCADE;

ALTER TABLE seats
ADD CONSTRAINT FK_seats  
FOREIGN KEY (seat_ID) REFERENCES members(seat_ID)  
ON UPDATE CASCADE  
ON DELETE CASCADE;

Am I on the right track? Will I be able to progress to a decent final product with this setup? suggestions/improvements? I don’t want to start all over in a couple of weeks because the database structure is of poor quality.

Answer 1

First of all I don’t see why you’re using a second table if any user can only hold one seat at any given time, secondly user_id in seats-table should be the same size as user_id in members table namely int(8), otherwise you won’t be able to seat users after a while, third issue is the duplication of seat_status, I suppose that was a mistake or you had another name for it.
In my opinion a better idea is to use a single table if it’s a 1->1 mapping and define it as

CREATE TABLE `members-table` (
   user_id int(8) not null auto_increment,
   user_name varchar(30) not null,
   user_pass varchar(255) not null,
   seat -- your type choice, should be nullable if not seated
);

Clearing the seats with this config would be as simple as

UPDATE `members-table` SET `seat` = NULL;