New prac thread

I spent the last two days doing validation and making my site more secure :-(.

Murphy's Technology Law 7
-- The attention span of a computer
is only as long as its electrical cord.

What's the best way to prevent students from signing up for the same course more than once, validating the data as it goes in, or selecting the data from course_student only once?

Hi Libby.

A bit of both..I guess.

Before a student registers, you could check the student_course table to see if they have already registered for that course.

if not, the data can then go into the table.


Murphy's Technology Law 7
-- The attention span of a computer
is only as long as its electrical cord.

I have tried various things without success. I have also tried googling but am obviously using the wrong jargon. Would I be right In saying I need to SELECT from the student_course table and then use if else statements?

Libby - I posted a solution in an early port as how to handle this?

Mac,
As far as I can see you replied "You can add if if you want - a simple select to check for personal details before inserting the student details into the db will do. But we assume a once-off registration system here, so it is not required." in a response to the query about duplicating student registrations.

This is a slightly different issue - about not inserting duplicate data into course_student - unless I'm missing some other post. I'm happy to google for it but I'd appreciate the correct jargon. I've looked an array_unique,INSERT IGNORE etc etc but I'm not finding anything that is really helpful.

It seems every time I want to post a question, it was already asked and answered. Like the one on duplicate student records..

Hi all
If any of you are having a similar problem to me with registrations being duplicated, I burnt some midnight oil and I discovered that the following does the trick:
a select query where sno AND cid are checked and then using mysql_num_rows to check whether a row like than exists, followed by a if else statement.

I found a most helpful site here:
http://www.php-editors.com/

A previous post:

the mysql_num_rows function counts the number of rows that exist depending on your select query. So "SELECT * FROM TABLE.." will count or the rows in the table. Adding a WHERE statement to the query will count the rows that fit the WHERE clause.

$query = "SELECT this FROM that_table WHERE that='$that'";

$result = mysql_query($query, $connection) or
die ("<p class=err>Error - Query failed: ".mysql_error()."";

$num_rows = mysql_num_rows($result);

Then you can use $num_rows (or whatever you decided to call it) however you want to use it, e.g.

if($num_rows > 1000) { echo "sorry, you can't register for this course since it is full"; //1000 students have already registered }

I have completed the project. When will we be able to upload it to server?