$query = $conn -> query("DELETE FROM table_name WHERE some_column = some_value");
if ($query){	echo "success";
}

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) { die("Connection failed: " . $conn->connect_error);
}
// sql to delete a record
$sql = "DELETE FROM MyGuests WHERE id=3";
if ($conn->query($sql) === TRUE) { echo "Record deleted successfully";
} else { echo "Error deleting record: " . $conn->error;
}
$conn->close();
?>