Using mysql you can only get data about how much mysql is using.
You can get information about how many rows, and how many fields per row, and you can even get the exact size of each field.
The problem is that if you have set up your database properly, you'll
be using variable length fields, like varchar and TEXT.
That means that you can't tell how long each field actually is.
The only way to get an accurate count would be to ask information about EVERY field in your database, and that would take too long.
You might want to set an "average size" for each row. Then you could simply count the rows and multiply by that average.
