How can debugging techniques be used to troubleshoot PHP code for database interactions?

Issue: When troubleshooting PHP code for database interactions, debugging techniques can be used to identify errors such as incorrect SQL queries, connection issues, or data retrieval problems. Debugging PHP code for database interactions can involve using functions like var_dump() or print_r() to display the contents of variables, checking for error messages from the database, and using tools like Xdebug for more advanced debugging capabilities. Additionally, logging errors to a file or outputting them to the browser can help pinpoint where issues are occurring in the code. 

// Example PHP code snippet for debugging database interactions
<?php

// Establish a connection to the database
$connection = mysqli_connect("localhost", "username", "password", "database");

// Check if the connection was successful
if (!$connection) {
    die("Connection failed: " . mysqli_connect_error());
}

// Perform a query to retrieve data from the database
$query = "SELECT * FROM table";
$result = mysqli_query($connection, $query);

// Check if the query was successful
if (!$result) {
    die("Query failed: " . mysqli_error($connection));
}

// Fetch and display the data
while ($row = mysqli_fetch_assoc($result)) {
    var_dump($row);
}

// Close the connection
mysqli_close($connection);

?>

Keywords

Xdebug var_dump error_reporting PDO SQL injection

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