What considerations should be made when handling database connections and queries in PHP scripts, especially when dealing with mysqli functions?

When handling database connections and queries in PHP scripts using mysqli functions, it is important to properly handle errors, close connections after use to prevent resource leaks, and sanitize user input to prevent SQL injection attacks. 

// Establishing a database connection
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database";

$conn = new mysqli($servername, $username, $password, $dbname);

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

// Perform a query
$sql = "SELECT * FROM table_name";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    // Output data of each row
    while($row = $result->fetch_assoc()) {
        echo "id: " . $row["id"]. " - Name: " . $row["name"]. "<br>";
    }
} else {
    echo "0 results";
}

// Close connection
$conn->close();

Keywords

database connections mysqli functions error handling prepared statements SQL injection

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