Problem when Handling repeated error values on php and mysql - php

Question

I have a PHP program that connect to a MariaDB databse.
I upload name as "numbers" and i defined the value as UNIQUE so I don´t want to be repeatated.
However I would like to handle the error when a vlaue is repeated:
This is the table I created:
Table in MariaDB
create table test(
-> id int NOT NULL AUTO_INCREMENT,
-> name varchar(255) UNIQUE,
-> date DATE NOT NULL,
-> PRIMARY KEY (id)
-> );
This is the script in PHP:
$host = "localhost";
$db_name = "xxx";
$username = "xxx";
$password = "xxx";
$connection = null;
$dt1=date("Y-m-d");
try{
$connection = new PDO("mysql:host=" . $host . ";dbname=" . $db_name, $username, $password);
$connection->exec("set names utf8");
}
catch(PDOException $exception){
echo "Connection error: " . $exception->getMessage();
}
function saveData($name, $dt1){
global $connection;
$query = "INSERT INTO test(name, date) VALUES( :name, :date )";
$callToDb = $connection->prepare( $query );
$name=htmlspecialchars(strip_tags($name));
//$dt1=htmlspecialchars(strip_tags($dt1));
$callToDb->bindParam(":name", $name);
$callToDb->bindParam(":date", $dt1);
if($callToDb->execute()){
//return '<h3 style="text-align:center;">registration submmited!</h3>';
//if (!$callToDb->execute()) {
// if ($callToDb->errno == 1062) {
// return '<h3 style="text-align:center;">VALUE REPEATED!</h3>';
// }
// else{
return '<h3 style="text-align:center;">registration submmited!</h3>';
// }
}
}
if( isset($_POST['submit'])) {
$name = htmlentities($_POST['name']);
$dt1 = htmlentities($_POST['date']);
//then you can use them in a PHP function.
$result = saveData($name, $dt1);
echo $result;
}
else{
echo '<h3 style="text-align:center;">A very detailed error message</h3>';
}
//header("location:javascript://history.go(-1)");
}
the code part after if($callToDb->execute()){ it is commented because it is not working but I would like to just show a message when the vlaue is repeated. The same than when a vlaue is registrated correctly.
The issue to handle duplicate error is in this part which at the moment I am not using in my code as is not working fine:
if (!$callToDb->execute()) {
if ($callToDb->errno == 1062) {
return '<h3 style="text-align:center;">VALUE REPEATED!</h3>';
}
else{
return '<h3 style="text-align:center;">registration submmited!</h3>';
}
}
Any idea why this part of the code it is not working?

Answer 1

Change your code with this one.
$affected_rows = $callToDb->rowCount();
if (!$callToDb->execute())
{
if ($affected_rows == 0)
{
return '<h3 style="text-align:center;">VALUE REPEATED!</h3>';
}
else
{
return '<h3 style="text-align:center;">registration submmited!</h3>';
}
}