如何将动态数据添加到数据库表中？

Question

I am trying to create a database for gym workout plans. This would have each member's workout plan, which comprises multiple exercises.

My question is: given that one member might have 5 exercises, another member 3, another 6, and so on, how can I store this in the database?

My thought process has been around hardcoding a set number of exercises in the table, and give the possibility of them being null (for exemple 10 exercises, but if you only use 5 exercises, everything else can be stored with nothing). But this doesn't feel very correct.

I am using MySQL for this.

Answer 1

Like @Sami pointed out, you are going to work on whats called a relational database .

Below is a simple database structure that will help you get started.

Members table

Table Name: tbl_members

Table Structure:

| member_id |member_name|member_contact|

Exercise or schedule table

Table Name: tbl_member_schedule

Table Structure:

| schedule_id | member_id |assigned_date|Schedule

In the tbl_member_schedule you can store the entire schedule as a JSON structure or you can further normalize. Since this is an example I am storing the entire schedule in JSON format inside the Schedule field.

Now when you want to retrieve the schedule of a specific member (member id: 1) you can query the database as follows:

select 
    tbl_members.member_id, tbl_members.member_name, 
    tbl_member_schedule.Schedule
from 
    tbl_members join
    tbl_member_schedule on tbl_members.member_id = tbl_member_schedule.member_id
where 
    tbl_members.member_id = 1;

So you JSON structure for your schedule could be

{ 
    day1: [
        {exerciseName: 'dumbbell curls', reps: '8 x 4'}, 
        {exerciseName: 'leg extension', reps: '8 x 3'}
    ],
    day2: [
        {exerciseName: 'dumbbell curls', reps: '8 x 4'}, 
        {exerciseName: 'leg extension', reps: '8 x 3'}
    ]
}