issue inserting data to database [duplicate] - php

Question

This question already has answers here:
When to use single quotes, double quotes, and backticks in MySQL
(13 answers)
Closed 7 years ago.
So i have made a php file to insert data into my database. I have been trying for a while and can't seem to figure out where my code is wrong.
I am using this form:
<form class="form-horizontal" role="form" method="post" action="#section4">
<div class="form-group">
<label for="first_name" class="col-sm-2 control-label">Name</label>
<div class="col-sm-10">
<input type="text" class="form-control" id="first_name" name="first_name" placeholder="First name" value="<?php echo htmlspecialchars($_POST['first_name']); ?>">
<?php echo "<p class='text-danger'>$errName</p>";?>
</div>
<div class="col-sm-10">
<input type="text" class="form-control" id="last_name" name="last_name" placeholder="Last name" value="<?php echo htmlspecialchars($_POST['last_name']); ?>">
<?php echo "<p class='text-danger'>$errName</p>";?>
</div>
</div>
<div class="form-group">
<label for="email" class="col-sm-2 control-label">Email</label>
<div class="col-sm-10">
<input type="email" class="form-control" id="email" name="email" placeholder="eksample#domain.com" value="<?php echo htmlspecialchars($_POST['email']); ?>">
<?php echo "<p class='text-danger'>$errEmail</p>";?>
</div>
</div>
<div class="form-group">
<div class="col-sm-10 col-sm-offset-2">
<input id="submit" name="submit" type="submit" value="Send" class="btn btn-primary">
</div>
</div>
</form>
first i have the variables of information from my form:
<?php
if ($_POST["submit"]) {
$first_name = $_POST['first_name'];
$last_name = $_POST['last_name'];
$email = $_POST['email'];}
Then i log onto my database:
$dbhost = 'mysql.info.dk';
$dbuser = 'myinfo';
$dbpass = 'mypass';
$dbname = 'moreinfo';
$conn = mysql_connect($dbhost, $dbuser, $dbpass) or die('Error connecting to mysql');
mysql_select_db($dbname);
i then "attempt" to insert the info from the form to a table in my database:
$sql = "INSERT INTO contacts(`first_name`, `last_name`, `email`) VALUES ([$first_name],[$last_name],[$email])";
and close my connection:
mysqli_close($conn);
?>
Can someone help me spot where my code is wrong?

Answer 1

Use single quotes while insering and use mysqli instead of mysql
$sql = "INSERT INTO contacts(`first_name`, `last_name`, `email`) VALUES ('$first_name','$last_name','$email')";