What are some debugging techniques that can be applied when encountering issues with data retrieval from a database in PHP scripts?

When encountering issues with data retrieval from a database in PHP scripts, some debugging techniques that can be applied include checking for errors in the SQL query, ensuring the database connection is established correctly, and verifying that the data is being fetched and processed properly. 

// Example code snippet for debugging data retrieval from a database in PHP
// Check for errors in the SQL query
$query = "SELECT * FROM users";
$result = mysqli_query($conn, $query);
if (!$result) {
    die("Error in SQL query: " . mysqli_error($conn));
}

// Ensure the database connection is established correctly
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}

// Verify that the data is being fetched and processed properly
while ($row = mysqli_fetch_assoc($result)) {
    // Process data here
}

Keywords

SQL injection PDO error handling var_dump query optimization

Related Questions