Very good post about the start of normalisation though on the practical part it's not actually in mysql's view actually joning tables. Just as a bit of a tip you lose allot of the good features of joining in MySQL if you just use FROM table1, table2, table3...

What you need to be doing to adhere to formally be joining tables is something like so:

SELECT *
FROM students
JOIN attendance ON students.studentid = attendance.studentid


There's other kinds of joints like 'INNER JOIN', 'OUTER JOIN', 'LEFT JOIN' and 'RIGHT JOIN' on the contrast FROM keyword/command will work, just it's more like using 'JOIN' but you do lose allot of MySQL's performance (i.e.when you want to omit any rows completely if the relational table you are joining has no data for the row on the primary table tuples/entities/rows).