php incrementing while loop

Question

$blanknumber = $_POST["blankstartnumber"];

while ($blanknumber <= ($_POST["blankendnumber"] ))
{    

echo "$blanknumber";
$blankid = $blanknumber;

$query = "INSERT INTO blank (Blank_ID) VALUES ('$blankid')";

mysql_query($query,$con);
$blanknumber++;

}

So the values are added into the database. Lets say if I have the starting number at 1 and ending at 5. It will all the those values, but it's still trying to add more into the database. I also tried adding an IF statement aswell. if ($blanknumber != $_POST["blankendnumber"])

12345 Error: Duplicate entry '5' for key 'PRIMARY'

This is a mysql error. You are trying to add a row with an existing primary key. Your if statement is useless since you are just taking the posted id and comparing it with ... the posted id. I think it's a more logical problem than a technical one. — Zakaria
– Zakaria, Commented Mar 21, 2011 at 21:50

Ryre · Accepted Answer · 2011-03-21 21:54:00Z

3

Make sure your $POST value is an integer; by default, I believe it will be cast as a string.

$_POST['varName'] = (int) $_POST['varName'];

edit:

$blanknumber = $_POST["blankstartnumber"];
while ($blanknumber <= ($_POST["blankendnumber"] ))

This should only execute once, since you're setting both comparison variables equal. Definitely 2x check your code.

edited Mar 21, 2011 at 21:54

answered Mar 21, 2011 at 21:48

Ryre

6,1895 gold badges33 silver badges47 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Marc B · Accepted Answer · 2011-03-21 21:49:03Z

1

The database error indicates that Blank_ID is your primary key for that table, and you'd already inserted a 5 into the row. A primary key's values can exist only once in the entire table - duplicates are forbidden (if they were allowed, it wouldn't be a primary key anymore).

If your while loop isn't ending, I'd suggest dumping out both the blankendnumber and blankstartnumber before the loop starts, making sure you've got the right values in there.

answered Mar 21, 2011 at 21:49

Marc B

362k44 gold badges433 silver badges508 bronze badges

Comments

Michael McTiernan · Accepted Answer · 2011-03-21 21:50:02Z

0

It looks like it's actually functioning properly, but you might not have tidy'ed up your db table prior to running. If your output was:

123455 Error: Duplicate entry '5'...

Then, you'd have a programming error, as 5 is getting run twice. Instead, I think you already have data in the blank table that causes a conflict.

Edit: to automatically have MySQL handle the duplicate key error gracefully, you can use the ON DUPLICATE KEY clause to update the row.

INSERT INTO blank (Blank_ID) VALUES (5) ON DUPLICATE KEY UPDATE mod_date = NOW();

answered Mar 21, 2011 at 21:50

Michael McTiernan

5,3132 gold badges27 silver badges16 bronze badges

Collectives™ on Stack Overflow

php incrementing while loop

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related