Which is the better way to create my mysql table? [closed] - php

Question

Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 6 years ago.
Improve this question
Based on my situation, should I combine all symptoms into one row as my method 1 below or method 2 that create more rows. The reason I don't like method 1 is that I have to use - to separate each symptom, and later I need to use php explode('-') to separate them and use LIKE to match them.
Method 2 will create more rows, and I think I will create more table to separate them.
Method 1:
disease symptoms
HIV pain-cough-hair loss
Flu cought-running nose-fever
cacer lose weight-fever-fatigue
Method 2:
disease symptoms
HIV pain
HIV cough
HIV hair loss
... ...
... ...

Answer 1

Out of your two methods, method 2 would be preferred. As #JNevill notes, storing multiple pieces of data in one column becomes a nightmare when searching or filtering data.
My full recommendation would be to use option 3 however. Take a look at the below design:
Table 1: DISEASES
+------+-----------+
| id | name |
+------+-----------+
| 1 | HIV |
|------|-----------|
| 2 | FLU |
|------|-----------|
| 3 | Cancer |
+------+-----------+
Primary Key:
id
Table 2: SYMPTOMS
+------+-----------+
| id | name |
+------+-----------+
| 1 | pain |
|------|-----------|
| 2 | cough |
|------|-----------|
| 3 | hair-loss |
+------+-----------+
Primary Key:
id
Table 3: DISEASES-SYMPTOMS
+-------------+--------------+
| disease_id | symptom_id |
+--------------+--------------+
| 1 | 1 |
|--------------|--------------|
| 1 | 2 |
|--------------|--------------|
| 1 | 3 |
+--------------+--------------+
Primary Key:
(disease_id, symptom_id)
Foreign Keys:
DISEASES.id -> DISEASES_SYMTPOMS.disease_id
SYMTPOMS.id -> DISEASES_SYMTPOMS.symptom_id
Establish your base tables DISEASES and SYMPTOMS. Then establish a 3rd table representing a JOIN of the first two tables. This normalization of the data will simply the structure of your application and prevent duplication of data since each disease can have multiple symptoms and each symptom can belong to multiple disease.
SAMPLE QUERY (MySQL):
SELECT
d.id,
d.name,
s.name
FROM DISEASES as d
INNER JOIN DISEASES_SYMPTOMS AS ds ON d.id = ds.disease_id
INNER JOIN SYMPTOMS AS s ON ds.symptom_id = s.id;
SAMPLE QUERY RESULT:
+------+----------------+----------------+
| id | disease_name | symptom_name |
+------+----------------+----------------+
| 1 | HIV | pain |
|------|----------------|----------------|
| 1 | HIV | cough |
|------|----------------|----------------|
| 1 | HIV | hair-loss |
+------+----------------+----------------+

Answer 2

It depends how normalized you want your database to be. The more normalized approach would be to create a symptoms table that houses all symptoms, a disease table that houses all diseases, and another table with links diseases to symptoms probably by disease_id and symptom_id. And the less normalized approach is like your method 1 where you include all the symptoms as a field in the table separated by some delimiter or put into an array if you are using a database that supports arrays.

Answer 3

Create two master tables for disease & symptoms. And then create a third table say .disease_symptom include the two foreign key column say disease_id & symptom_id and refer to the corresponding master table