What is the idea of a simple reply system? Is my idea true?

I am a beginner in php. I am writing a small forum with only a little bit of knowledge. I have a lot of questions. my own idea is as follows: for example, my website address is xxx.com, click a post to go in and reply, get the post id from mySQL, and the website will jump to xxx. comt? Postid; however... I am a beginner in php. Now I am writing a small forum with only some knowledge.

My own ideas are as follows:

For example, if the address of my website is xxx.com, click a post to reply, and obtain the post id from mySQL, the URL will jump to xxx.com/t /? Post = id;
Then, place an index. php file under the/t directory, set the style, and cycle the reply data in mySQL.
There is no problem with running now.

But I always think there is a problem with my thinking. Will the data returned from the Forum be generated in real time? I don't know what I can't clearly express. I just want to briefly describe the conventional reply solution ...?

Reply content:

I am a beginner in php. I am writing a small forum with only a little bit of knowledge. I have a lot of questions.

My own ideas are as follows:

For example, if the address of my website is xxx.com, click a post to reply, and obtain the post id from mySQL, the URL will jump to xxx.com/t /? Post = id;
Then, place an index. php file under the/t directory, set the style, and cycle the reply data in mySQL.
There is no problem with running now.

But I always think there is a problem with my thinking. Will the data returned from the Forum be generated in real time? I don't know what I can't clearly express. I just want to briefly describe the conventional reply solution ...?

Generally, posts and replies are placed in two tables.

Select from reply where primary post id = ooxx limit page_size offset page_number;

Then, we can introduce cache and other optimization mechanisms considering the performance.