display message to let user know that the value already exist - php

Question

I want to display an error message if the insert already exists.
I've made name unique in the database and if I enter the same value, it does not insert. Just as I wanted. Here is my code:
$query = "INSERT INTO register(name) VALUES('$foo')";
mysql_query($query) or die('An Error occurred' . mysql_error());
Now I want to echo a message to let the user know that the value he has entered is already present in the database and will not be inserted. Anyone?

Answer 1

I take it you are collecting $foo from a form?
what I would do is an sql query of the table register collecting the name field then when you collect the name entered in the form and its posted you can run an if condition against the name field you have already gathered using the sql statement and if there is a name = to the name they enter on the field they can receive a message and exit before the sql injection into the register table.

Answer 2

The simpliest way:
$res = mysql_query($query):
if ($res)
echo 'Insertion ok';
else
echo 'error: name already exists';
A better way: do first a SELECT query to see if name exists or not.
Note: you should think about moving from mysql_* to mysqli_* or PDO

Answer 3

Try this :
$query = "INSERT INTO register(name) VALUES('$name')";
$user = mysql_query($query):
if ($user)
echo 'User Register';
else
echo 'User Already Exist';

Answer 4

As per Melon's comment, you should use mysqli.
// Create your connection
$mysqli = new mysqli($host, $user, $pass, $dbname);
// Do your query
$mysqli->query("INSERT INTO register(name) VALUES('$foo')");
if($mysqli->affected_rows == 0) {
// Your chosen method of alerting the user goes here
}

Answer 5

\\this first part collects name information from your table.
$name="SELECT name FROM register";
$name_query = mysqli_query($db_conx, $name);
$numrows = mysqli_num_rows($name_query);
if($numrows < 1){
echo "cannot find user";
header ("location: index.php");
}
while ($row = mysqli_fetch_array($name_query, MYSQLI_ASSOC)){
$name = $row["name"];
}
\\ this part gets the name from your form
if (isset($_POST['class']) && ($_POST['class'] !='')){
$foo = $_POST['foo'];
\\this part checks to see if the 2 values are equal
if ($name == $foo){
echo "This name has already been used try again";
\\this part then adds the name if its not already in the database
}else{
$query = "INSERT INTO register(name) VALUES('$foo')";
mysql_query($query) or die('An Error occurred' . mysql_error());
}
}
//then all you need to do is create your form to post the foo or name so it can be collected and passed through the querys.