PHP code that queries a MySQL database and finds duplicate latitude and longitude pairs

Sure, here's an example PHP code that queries a MySQL database and finds duplicate latitude and longitude pairs:

<?php
// database connection parameters
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database_name";

// connect to the database
$conn = new mysqli($servername, $username, $password, $dbname);

// check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

// query to find duplicates
$sql = "SELECT latitude, longitude, COUNT(*) 
        FROM locations 
        GROUP BY latitude, longitude 
        HAVING COUNT(*) > 1";

// execute the query
$result = $conn->query($sql);

// check if any duplicates were found
if ($result->num_rows > 0) {
    // output data of each row
    while($row = $result->fetch_assoc()) {
        echo "Latitude: " . $row["latitude"]. " - Longitude: " . $row["longitude"]. " - Count: " . $row["COUNT(*)"]. "<br>";
    }
} else {
    echo "No duplicate latitude and longitude pairs found.";
}

// close database connection
$conn->close();
?>

Note that you'll need to replace the database connection parameters ($servername, $username, $password, and $dbname) with your own values. Also, the code assumes that the table with the location data is named locations, so you may need to change that as well. Finally, the code simply outputs the duplicate latitude and longitude pairs to the browser, but you can modify it to perform any other desired action, such as deleting the duplicates or updating their values.