mysqli_free_results的问题

Question

I'm having trouble using the mysqli_free_result() function. I am nesting queries and it seems when I free the results it stops the initial query from running its loop with the while() function. Am I using the mysqli_free_result() improperly? If I change the name of the 2nd query from $results to $results2 it works fine. Seems there is an issue with the variables over writting, which is where I thought mysqli_free_result() would help but apparently not.

Here is a sample code similar to what I am trying to do.

<?php

// 1st query
$query = '';

// Run the 1st query
if( $results = mysqli_query( $db_connect, $query ) ) {
    while( $result = mysqli_fetch_assoc( $results ) ) {

        // 2nd query
        $query = '';

        // Run the 2nd query
        if( $results = mysqli_query( $db_connect, $query ) ) {
            while( $result = mysqli_fetch_assoc( $results ) ) {

            }
            mysqli_free_result( $results );
        }

    }
    mysqli_free_result( $results );
}

?>

Answer 1

Try using a different variable name for your inner query. Currently you are overwriting the $results on every run of the outer while loop.

<?php

// 1st query
$query = '';

// Run the 1st query
if( $results = mysqli_query( $db_connect, $query ) ) {
    while( $result = mysqli_fetch_assoc( $results ) ) {

        // 2nd query
        $query = '';

        // Run the 2nd query
        if( $results_2 = mysqli_query( $db_connect, $query ) ) {
            while( $result_2 = mysqli_fetch_assoc( $results_2 ) ) {

            }
            mysqli_free_result( $results_2 );
        }

    }
    mysqli_free_result( $results );
}

?>

Update: As already pointed out on other comments and answers, mysqli_stmt_free_result frees the memory for the supplied statement handle as stated in the docs http://www.php.net/manual/en/mysqli-stmt.free-result.php. As @andrewsi points out, the issue is variable scoping issue.