How To Store Tags In A Database Using MySQL and PHP?

Question

I wanted to create a database that will store the tags that users enter for their questions and then display them all for each individual question posted; something like here on

Answer 1

Tables:

CREATE TABLE questions_tags (
tag_id INT INT NOT NULL,
question_id INT NOT NULL,
);

CREATE TABLE tags (
id INT UNSIGNED NOT NULL AUTO_INCREMENT,
tag VARCHAR(255) NOT NULL,
PRIMARY KEY (id)
);

---

SQL

Select the tag related to a question

SELECT     tag_id
FROM         question_tags
WHERE     question_id = $yourquestionid'

Select the questions related to a tag

SELECT     question_id
FROM         question_tags
WHERE     tag_id = $yourtagid'

Count how many times a tag has been used

SELECT COUNT(tag_id) 
FROM question_tags 
where tag_id=$yourtagid

Make a tag cloud

SELECT COUNT(tag_id)
FROM question_tags 
GROUP BY tag;