SQL query for getting subscription dates - sql

Question

I have these tables into which I would like to check user subscription period:
Entities:
CREATE TABLE `orders` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`city` varchar(30) DEFAULT NULL,
`CONTENT` text DEFAULT NULL,
`country` varchar(50) DEFAULT NULL,
`created_at` datetime(6) DEFAULT NULL,
`discount` decimal(8,2) DEFAULT NULL,
`email` varchar(50) DEFAULT NULL,
`first_name` varchar(50) DEFAULT NULL,
`grand_total` decimal(8,2) DEFAULT NULL,
`item_discount` decimal(8,2) DEFAULT NULL,
`last_name` varchar(50) DEFAULT NULL,
`line1` varchar(50) DEFAULT NULL,
`line2` varchar(50) DEFAULT NULL,
`middle_name` varchar(50) DEFAULT NULL,
`mobile` varchar(15) DEFAULT NULL,
`promo` varchar(100) DEFAULT NULL,
`province` varchar(50) DEFAULT NULL,
`session_id` int(11) DEFAULT NULL,
`shipping` decimal(8,2) DEFAULT NULL,
`status` varchar(100) DEFAULT NULL,
`sub_total` decimal(8,2) DEFAULT NULL,
`tax` decimal(8,2) DEFAULT NULL,
`token` varchar(100) DEFAULT NULL,
`total` decimal(8,2) DEFAULT NULL,
`updated_at` datetime(6) DEFAULT NULL,
`user_id` int(11) DEFAULT NULL,
`phone` varchar(50) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=65 DEFAULT CHARSET=latin1
CREATE TABLE `subscription` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`amount` decimal(19,2) DEFAULT NULL,
`created_at` datetime(6) DEFAULT NULL,
`currency` varchar(20) DEFAULT NULL,
`duration` bigint(20) DEFAULT NULL,
`end_at` datetime(6) DEFAULT NULL,
`error` varchar(200) DEFAULT NULL,
`order_id` int(11) DEFAULT NULL,
`product` varchar(20) DEFAULT NULL,
`run_at` datetime(6) DEFAULT NULL,
`start_at` datetime(6) DEFAULT NULL,
`status` varchar(20) DEFAULT NULL,
`updated_at` datetime(6) DEFAULT NULL,
`title` varchar(20) DEFAULT NULL,
`parent_transaction_id` int(11) DEFAULT NULL,
`parent_transactionId` int(11) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=23443556 DEFAULT CHARSET=latin1
CREATE TABLE `payment_transactions` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`amount` decimal(19,2) DEFAULT NULL,
`code` varchar(100) DEFAULT NULL,
`CONTENT` text DEFAULT NULL,
`created_at` datetime(6) DEFAULT NULL,
`currency` varchar(20) DEFAULT NULL,
`error` varchar(200) DEFAULT NULL,
`external_id` varchar(255) DEFAULT NULL,
`gateway` varchar(20) DEFAULT NULL,
`mode` int(11) DEFAULT NULL,
`order_id` int(11) DEFAULT NULL,
`reconciled_at` datetime(6) DEFAULT NULL,
`reference_transaction_id` int(11) DEFAULT NULL,
`status` varchar(20) DEFAULT NULL,
`type` varchar(20) DEFAULT NULL,
`unique_transactionId` varchar(50) DEFAULT NULL,
`updated_at` datetime(6) DEFAULT NULL,
`user_id` int(11) DEFAULT NULL,
`unique_transaction_id` varchar(50) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=119 DEFAULT CHARSET=latin1
I'm new to database table design so I need to ask what table relations relations should I use to get the user subscription period using user id?
Is it a good idea to use Orders table as a main table and make SQL queries with JOIN to get the subscription period using user id?
JSFFiddle: http://sqlfiddle.com/#!9/262df6/1

Answer 1

As per your requirement, you need to get the user subscription period using user id.
You can get user subscription period and other data from SUBSCRIPTION table by joining ORDERS table, as they have order_id you can directly join the two tables by querying for user_id in where condition.
select subs.* from subscription subs
left join orders odr on odr.id = subs.order_id
where odr.user_id = 221 -- pass the required user id
specify the required columns and query for the userid in where condition
verified with JSFiddle you shared by adding a record in subscription table : http://sqlfiddle.com/#!9/b834fc/2

Answer 2

The main thing to consider here is how you'll normally be wanting to access these tables in the future. Based on what you've posted, I'm going to assume there are users (I don't see a users table), and that they place orders and also have subscriptions.
The thing these share in common - the relation between the two - is the user. Having the user be the focal point also creates a 1-to-many relationship, as opposed to a many-to-many relationship, which is much easier to manage. So, rather than having orders tied to subscriptions, which could get confusing, I would recommend having them both tied to the user. What if a single user has multiple orders, and multiple subscriptions? Which order would you relate to which subscription?
If you have a users table, then I would structure it so each user gets their own unique primary key. Let's call it user_id. Then, have the user_id in both the subscriptions (relating the subscriptions back to the user) and also the orders (relating orders back to the user).
With the user_id relating the two, you could relate the orders and subscriptions easily.