The WHERE clause in php mysqli

The following example selects all rows from the "Persons" table where "FirstName='Peter'":

<?php
$con=mysqli_connect("example.com","peter","abc123","my_db");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }

$result = mysqli_query($con,"SELECT * FROM Persons
WHERE FirstName='Peter'");

while($row = mysqli_fetch_array($result))
  {
  echo $row['FirstName'] . " " . $row['LastName'];
  echo "<br>";
  }
?>

The output of the code above will be:

Peter Griffin