This question might seem strange but I have been searching for an answer for a long time and I couldn’t find any.
Let’s suppose you have a blog and this blog has many post entries just like any other blog. Now each post can have simple user comments. No like buttons or any other resource that would require data management. Now the query is: Can I store user comments on a single text file? Each post will be associated to a text file that holds the comments. So, if I have n posts I’ll have n text files.
I know I can perfectly do this, but I have never seen it anywhere else and no one is talking about it. For me this seems better than storing all coments from all posts in a single mysql table but I don’t know what makes it so bad that no one has implemented it yet.
Storing comments in text files associated with corresponding post? Lest see if it’s good idea.
Okay adding new comments easy – write new text to the file. But what about format of your data? CSV? Ok then you would have to parse it before rendering.
Paging. If you have a lot of comments you may consider creating paging navigation for it. It can be done easily, sure. But you would need to open the file and read all the records to extract say 20.
Approve your comments. Someone posted new comment. You place it with pending status. So.. In admin panel you need to find those marked comments and process then accordingly – save or remove. Do you think it’s convinient with text files? The same if use decided to remove its comment himself.
Reading files if you have many comments and many posts will be slower the it would be in case of database.
Scalability. One day you deside to extend you comments functionality to let one comment to respond to another. How would you do it with text files? Or example from comments by nico: “In 6 months time, when you will want to add a rating field to the comments… you’ll have a big headache. Or, just run a simple ALTER query”.
This is just for beggining. Someone may add something.