What are some common pitfalls when using mysqli::multi_query in PHP?

One common pitfall when using mysqli::multi_query in PHP is not properly checking for errors after executing the queries. It's important to check the return value of mysqli::multi_query to ensure that the queries were executed successfully. Another pitfall is not freeing the result set after executing the queries, which can lead to memory leaks. Make sure to free the result set using mysqli::free_result after fetching the results. 

// Example of properly checking for errors and freeing result set after using mysqli::multi_query

// Assuming $mysqli is your mysqli connection

$query = "SELECT * FROM table1; SELECT * FROM table2";
if ($mysqli->multi_query($query)) {
    do {
        if ($result = $mysqli->store_result()) {
            while ($row = $result->fetch_assoc()) {
                // Process results
            }
            $result->free();
        }
    } while ($mysqli->next_result());

    if ($mysqli->errno) {
        echo "Error executing queries: " . $mysqli->error;
    }
} else {
    echo "Error executing multi query: " . $mysqli->error;
}

Keywords

mysqli multi_query PHP SQL injection error handling

Related Questions