Connection Problems

Troycus · January 5, 2012, 3:07pm

Hello,

I am new to php and any help would be appreciated. I have a simple connection script I wrote for php to put data into a mysql database. I got it to work once, but when I refresh the browser to try it again, I get an error. What am I doing wrong? Here’s the code:

html doc:

<?php include("connec.php"); ?> Hello username:
password:

Here is the connection file:

<?php $db_host = 'localhost'; $db_user = 'root'; $db_pass = 'root'; $dbc = mysql_connect($db_host,$db_user,$db_pass); if(!$dbc){ die("No Server!"); } echo "
"; $dbase = mysql_select_db("testing", $dbc); if(!$dbase){ die("No Database!"); } $value = $_POST['username']; $value1 = $_POST['password']; $sql = "INSERT INTO login (username, password) VALUES ('$value', '$value1')"; if(!mysql_query($sql)){ die("No Tables!"); } mysql_close(); ?>

I got it to work once but when I refresh the browser, I get an error. It got it to work again When I emptied the database. Strange…

Any help would be appreciated.

I’m using a Macbook Pro and mamp.

jSherz · January 5, 2012, 7:11pm

Before using $_POST, $_GET, $_COOKIE, $_SESSION or $_REQUEST data, you should check that it is set, with the isset function:

[php]$value = $_POST[‘username’];
$value1 = $_POST[‘password’];

$sql = “INSERT INTO login (username, password) VALUES (’$value’, ‘$value1’)”;

if(!mysql_query($sql)){
die(“No Tables!”);
}[/php]

Becomes:

[php]if(isset($_POST[‘username’]) && isset($_POST[‘password’])) {
$value = $_POST[‘username’];
$value1 = $_POST[‘password’];

$sql = "INSERT INTO login (username, password) VALUES ('$value', '$value1')";

if(!mysql_query($sql)){
    die("No Tables!");
}

}[/php]

Also, which error do you get?

Troycus · January 5, 2012, 7:54pm

I’m getting the error “No Fields!” I created for testing purposes. Everything works except for inserting thing into the database. It worked the first time and it works when I empty the mysql database. I’m curious, what does the “isset” use for?

Thanks for your help.

jSherz · January 5, 2012, 7:58pm

Does it still not work with the isset?

isset checks whether a variable exists. When you’re accepting user input, it may not have been sent (e.g. if the page has just been viewed without the form being submitted).

Troycus · January 5, 2012, 11:43pm

I haven’t tried yet but I will. It looks like you have an if statement first to use isset?

Troycus · January 6, 2012, 12:32am

It Worked! Thanks you’re Awesome! Why didn’t mine code work? If you have time to explain.

jSherz · January 6, 2012, 7:53am

If the MySQL query failed (returning FALSE), then it would give the error message you had. It’s probably because you tried to insert a blank record (as the form had not been filled). Some MySQL table items will not allow a NULL or blank entry.

Troycus · January 6, 2012, 10:21am

That was exactly what was happening. When I would refresh the screen sometimes, I would go back and check the database and a blank record would be in there. When you sent me the first and second response, It started making sense. I see why you’re an expert.

Thanks a million.