What are the advantages and disadvantages of using fetchAll() in PDO to retrieve query results?

When using fetchAll() in PDO to retrieve query results, the main advantage is that it fetches all the results at once and returns them as an array, which can be convenient for processing large result sets. However, this can also be a disadvantage when dealing with very large result sets as it may consume a lot of memory. It's important to consider the memory usage and potential performance impact when deciding whether to use fetchAll(). 

// Example of using fetchAll() in PDO to retrieve query results
$stmt = $pdo->query("SELECT * FROM users");
$results = $stmt->fetchAll(PDO::FETCH_ASSOC);

// Loop through the results
foreach ($results as $row) {
    // Process each row
}

Keywords

fetchAll PDO query results advantages disadvantages

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