What are the differences between using while() and do-while() loops when handling database query results in PHP?

When handling database query results in PHP, the main difference between using a while() loop and a do-while() loop is the initial check for the condition. In a while() loop, the condition is checked before the loop body is executed, which means that if the query returns no results, the loop will not run at all. On the other hand, a do-while() loop will always run at least once before checking the condition, making it useful when you want to process the first result even if there might not be any subsequent results. Here is an example of using a while() loop to iterate over database query results in PHP:

// Assuming $result is the result of a database query
while ($row = mysqli_fetch_assoc($result)) {
    // Process each row of the query result
    echo $row['column_name'];
}
```

And here is an example of using a do-while() loop to achieve the same result:

```php
// Assuming $result is the result of a database query
do {
    $row = mysqli_fetch_assoc($result);
    // Process each row of the query result
    echo $row['column_name'];
} while ($row);