How can one ensure that the SQL query is correctly executed and returns the expected results in PHP?

To ensure that the SQL query is correctly executed and returns the expected results in PHP, you should use prepared statements to prevent SQL injection attacks and ensure proper escaping of user input. Additionally, you should check for errors after executing the query to handle any potential issues that may arise during the execution. 

// Establish 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);
}

// Prepare and execute the SQL query
$stmt = $conn->prepare("SELECT * FROM table WHERE column = ?");
$stmt->bind_param("s", $column_value);

$column_value = "some_value";
$stmt->execute();

// Check for errors and fetch results
if ($stmt->error) {
    echo "Error: " . $stmt->error;
} else {
    $result = $stmt->get_result();
    
    while ($row = $result->fetch_assoc()) {
        // Process the results
    }
}

// Close the statement and connection
$stmt->close();
$conn->close();

Keywords

SQL query execution PHP error handling result validation

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