Updating SQL database using PHP

Question

I am trying to make a password retrieval system on my site, and I am having problems updating the password reset field in my database. I have tried everything, but nothing seems to work.

This is my code so far:

$passwordreset = md5(mt_rand()) . md5(mt_rand()) . md5(mt_rand());

$con = mysql_connect("localhost","XXX","XXX");
if (!$con) {
  die('Could not connect: ' . mysql_error());
}

mysql_select_db("database", $con);

mysql_query("UPDATE members SET passwordreset = $passwordreset WHERE id = $id");

When I try to insert the data I get the error:

Error: Query was empty

Any help would be appreciated, Thanks.

Are you sure the message comes from this particular query? How do you get the error? — Pekka
– Pekka, Commented Dec 17, 2009 at 12:51

Pascal MARTIN · Accepted Answer · 2009-12-17 12:02:09Z

2

Not sure it's the only problem, but I'm guessing your passwordreset field is a string, in the database -- to store a concatenation of several md5, which are strings, it has to.

So, there should be quotes arround the value you put in this field, in the SQL query :

mysql_query("UPDATE members SET passwordreset = '$passwordreset' WHERE id = $id");

And, in a general case, you should escape your string values with mysql_real_escape_string :

mysql_query("UPDATE members SET passwordreset = '" 
    . mysql_real_escape_string($passwordreset) 
    . "' WHERE id = $id");

It won't change anything here, as there is no quote in a md5... But it's a good practice to always do it, to never find yourself in a situation where it was necessary and you didn't do it.

answered Dec 17, 2009 at 12:02

Pascal MARTIN

402k82 gold badges665 silver badges666 bronze badges

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

1 Comment

Crazyd22 Over a year ago

Thanks for your reply, still doesn't work, getting the same error

Residuum · Accepted Answer · 2009-12-17 12:01:21Z

0

I am not sure, if you get an empty query error for this, but you need ticks around the values:

mysql_query("UPDATE members SET passwordreset = '$passwordreset' WHERE id = '$id'");

answered Dec 17, 2009 at 12:01

Residuum

12.1k7 gold badges42 silver badges70 bronze badges

Comments

score 0 · Accepted Answer · 2013-02-27 15:32:31Z

0

I guess the backticks around the names of the columns are missing, try:

mysql_query("UPDATE members SET `passwordreset` = '$passwordreset' WHERE `id` = '$id'");

edited Feb 27, 2013 at 15:32

answered Dec 17, 2009 at 12:03

user156676

Comments

Pekka · Accepted Answer · 2013-02-27 15:32:48Z

0

Are the two line breaks after $passwordreset intentional? Can you try removing them?

edited Feb 27, 2013 at 15:32

user142162

answered Dec 17, 2009 at 12:01

Pekka

451k150 gold badges989 silver badges1.1k bronze badges

1 Comment

user156676 Over a year ago

They shouldn't be a problem. I have lots of long MySQL statements here with line breaks and php / MySQL have no problems with them.

Collectives™ on Stack Overflow

Updating SQL database using PHP

4 Answers 4

1 Comment

Comments

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

1 Comment

Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related