Why is it recommended not to use "SELECT *" in SQL queries when working with PHP and MySQL?

Using "SELECT *" in SQL queries is not recommended because it can lead to performance issues and potential security vulnerabilities. When working with PHP and MySQL, it is better to explicitly specify the columns you want to retrieve to improve query performance and prevent unnecessary data retrieval. This also helps in avoiding potential security risks such as exposing sensitive data if the table schema changes. 

<?php
// Explicitly specify the columns you want to retrieve
$sql = "SELECT column1, column2, column3 FROM your_table_name";
$result = mysqli_query($connection, $sql);

// Process the query result
if (mysqli_num_rows($result) > 0) {
    while ($row = mysqli_fetch_assoc($result)) {
        // Process the retrieved data
    }
} else {
    echo "No results found.";
}
?>

Keywords

PHP MySQL SQL queries performance security

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