in a 'for' Loop show different total rows than query PHP + MYSQL

Question

this is my first question here, sorry for my bad english, the for loop result show "Done! 6000 rows affected." when the table have 6,235 rows, what is wrong?.

<?php
    //get the total rows of Members table.
        $count_members = mysqli_query($ipb_connection,'SELECT * FROM ' . $from_prefix. 'members');
        $totalMembers = mysqli_num_rows($count_members);

        mysqli_free_result($count_members);

        //start convertion
        $limit = 500;
        $output = '';
        //maybe there are better solutions for this
        for ($i=0;$i<=$totalMembers;$i+=$limit)
        {
            $get_members = mysqli_query($ipb_connection,'
                SELECT
                    m.member_id AS id_member, SUBSTRING(m.name, 1, 80) AS member_name,
                    m.joined AS date_registered, m.posts,
                    m.member_group_id AS id_group,
                    m.last_visit AS last_login, SUBSTRING(m.name, 1, 255) AS real_name,
                    IFNULL(m.msg_count_total, 0) AS instant_messages,
                    SUBSTRING(m.conv_password, 1, 64) AS passwd,
                    SUBSTRING(m.email, 1, 255) AS email_address,
                    STR_TO_DATE(IF (m.bday_year = 0 AND m.bday_month != 0 AND m.bday_day != 0, CONCAT("0004-", m.bday_month, '-', m.bday_day), CONCAT_WS('-', IF(m.bday_year <= 4, 1, m.bday_year), IF(m.bday_month = 0, 1, m.bday_month), IF(m.bday_day = 0, 1, m.bday_day))), "%Y-%m-%d") AS birthdate,
                    s.cache_content as signature,
                    "" AS lngfile, "" AS buddy_list,
                    "" AS pm_ignore_list, "" AS message_labels, "" AS personal_text,
                    "" AS time_format, "" AS usertitle, "" AS member_ip, "" AS secret_question,
                    "" AS secret_answer, "" AS validation_code, "" AS additional_groups,
                    "" AS smiley_set, "" AS password_salt,
                    pf.field_2 AS msn, pf.field_3 AS website_url, pf.field_6 AS location,
                    pf.field_1 AS aim, pf.field_4 AS icq, pf.field_8 AS yim,
                    IF(pf.field_5 = "m" AND pf.field_5 != "u",1,2) AS gender
                FROM {string:prefix}members m
                LEFT JOIN foro_content_cache_sigs s on m.member_id = s.cache_content_id
                LEFT JOIN foro_pfields_content pf on m.member_id = pf.member_id
                WHERE m.member_id != 0
                LIMIT ' . $i .', ' . $limit);

                $output = 'Done! ' . $i . ' rows affected.';
        }

        echo $output;
?>

the result must be "Done! 6235 rows affected!". is first time using for loops with limit querys.

regards.

EDIT:

i use the folowing way:

$limit = 100;
    $parts = $totalMembers / $limit;
    $output = '';
    $affected = 0;
    //maybe there are better solutions for this
    for ($i=0;$i<=$totalMembers;$i+=$limit * $parts)
    {
        //query here
    }

and now show me Done! 6235 rows affected, is correct that way?.

Answer 1

It's just a display problem, your query retrieve the 6235 rows because you display the "from limit" and not the "how many i retrieve"

If we do your loop step by step (we imagine it's until 1235, it's shorter)

$limit = 500;
$output = '';
//maybe there are better solutions for this
for ($i=0;$i<=$totalMembers;$i+=$limit)
{
   // query here
   $output = 'Done! ' . $i . ' rows affected.';
}

• First loop: $i = 0 to 500, ouput = "Done! 0 rows affected"
• Second loop: $i = 500 to 1000, ouput = "Done! 500 rows affected"
• Thirt loop: $i = 1000 to 1235, ouput = "Done! 1000 rows affected"

If your problem is "I don't retrieve all data", you don't have a problem

If your problem is the display, add to $i the count of rows from mysqli_query ( http://www.w3schools.com/php/func_mysqli_num_rows.asp )

So the result is $ouput = "Done! ".($i + mysqli_num_rows($get_members))." row affected"