如何在MySQL中更新多个记录？

Question

I am trying to pull records from a table and update one filed in them. I am able to pull the records and create the form, however the update part is not working.

The code below is above my HTML section.

<?php require_once('../Connections/connect.php'); ?>
<?php
session_start();
$MM_authorizedUsers = "";
$MM_donotCheckaccess = "true";

// *** Restrict Access To Page: Grant or deny access to this page
function isAuthorized($strUsers, $strGroups, $UserName, $UserGroup) { 
  // For security, start by assuming the visitor is NOT authorized. 
  $isValid = False; 

  // When a visitor has logged into this site, the Session variable MM_Username set equal to their username. 
  // Therefore, we know that a user is NOT logged in if that Session variable is blank. 
  if (!empty($UserName)) { 
    // Besides being logged in, you may restrict access to only certain users based on an ID established when they log in. 
    // Parse the strings into arrays. 
    $arrUsers = Explode(",", $strUsers); 
    $arrGroups = Explode(",", $strGroups); 
    if (in_array($UserName, $arrUsers)) { 
      $isValid = true; 
    } 
    // Or, you may restrict access to only certain users based on their username. 
    if (in_array($UserGroup, $arrGroups)) { 
      $isValid = true; 
    } 
    if (($strUsers == "") && true) { 
      $isValid = true; 
    } 
  } 
  return $isValid; 
}

$MM_restrictGoTo = "sorry.php";
if (!((isset($HTTP_SESSION_VARS['MM_Username'])) && (isAuthorized("",$MM_authorizedUsers, $HTTP_SESSION_VARS['MM_Username'], $HTTP_SESSION_VARS['MM_UserGroup'])))) {   
  $MM_qsChar = "?";
  $MM_referrer = $HTTP_SERVER_VARS['PHP_SELF'];
  if (strpos($MM_restrictGoTo, "?")) $MM_qsChar = "&";
  if (isset($QUERY_STRING) && strlen($QUERY_STRING) > 0) 
  $MM_referrer .= "?" . $QUERY_STRING;
  $MM_restrictGoTo = $MM_restrictGoTo. $MM_qsChar . "accesscheck=" . urlencode($MM_referrer);
  header("Location: ". $MM_restrictGoTo); 
  exit;
}
?>
<?php
$col_points = "0";
if (isset($HTTP_GET_VARS['tournament_id_num'])) {
  $col_points = (get_magic_quotes_gpc()) ? $HTTP_GET_VARS['tournament_id_num'] : addslashes($HTTP_GET_VARS['tournament_id_num']);
}
mysql_select_db($database_camsports, $camsports);
$query_points = sprintf("SELECT cam_registered_tbl.team_id_num, cam_registered_tbl.wins, cam_registered_tbl.losses, cam_registered_tbl.points, cam_teams_tbl.team_name, cam_registered_tbl.registered_id_num FROM cam_registered_tbl, cam_teams_tbl WHERE cam_registered_tbl.tournament_id_num=%s AND cam_teams_tbl.team_id_num=cam_registered_tbl.team_id_num", $col_points);
$points = mysql_query($query_points, $camsports) or die(mysql_error());
$row_points = mysql_fetch_assoc($points);
$totalRows_points = mysql_num_rows($points);

$col_tournament = "0";
if (isset($HTTP_GET_VARS['tournament_id_num'])) {
  $col_tournament = (get_magic_quotes_gpc()) ? $HTTP_GET_VARS['tournament_id_num'] : addslashes($HTTP_GET_VARS['tournament_id_num']);
}
mysql_select_db($database_camsports, $camsports);
$query_tournament = sprintf("SELECT cam_tournaments_tbl.tournament_name FROM cam_tournaments_tbl WHERE cam_tournaments_tbl.tournament_id_num=%s", $col_tournament);
$tournament = mysql_query($query_tournament, $camsports) or die(mysql_error());
$row_tournament = mysql_fetch_assoc($tournament);
$totalRows_tournament = mysql_num_rows($tournament);
?>
<?php

//This loops through all the records that have been displayed on the page.

for ($index = 0; $index <= $index_count; $index++) {


    /*
    This part sets a variable with the names we created in the first section.  
    We start with 0 and go until the number saved in the $index_count variable.
    */ 

    $varregistered_id_num = 'registered_id_num'.$index;
    $varteam_name = 'team_name'.$index;
    $varwins = 'wins'.$index;
    $varlosses = 'losses'.$index;
    $varpoints = 'points'.$index;


    /*
    This is the variable variable section.  We take the value that was assigned 
    to each name variable.  For example the first time through the loop we are 
    at the record assigned with SubmissionID0.  The value given to SubmissionID0 
    is set from the first section.  We access this value by taking the variable 
    variable of what SubmissionID0 is.
    */

    $registered_id_numvalue = $$varregistered_id_num;
    $team_namevalue = $$varteam_name;
    $winsvalue = $$varwins;
    $lossesvalue = $$varlosses;
    $pointsvalue = $$varpoints;


    //Update the database

    $sql = "UPDATE cam_registered_tbl SET points='$pointsvalue',wins='$winsvalue',".
        "losses='$lossesvalue' WHERE registered_id_num='$registered_id_numvalue'";
    $result = mysql_query($sql);

    //If the link was marked approved set the value of the Approved field

    if ($goto == '1') {
        $insertGoTo = "menu.php";
        header(sprintf("Location: %s", $insertGoTo));
    }


}

?>

This code is in the body section

<div align="center">
  <p><font size="4"><?php echo $row_tournament['tournament_name']; ?></font></p>
  </div>
<?php
//Initialize counter variables

$index = 0;
$index_count = 0;
echo "<form method=post action=$PHP_SELF>\n";
echo "<table>\n";
echo "<tr><td><b>Team</b></td>".
    "<td><b>Points</b></td></tr>\n";


/*
Assuming we already have retrieved the records from the database into an array setting 
$myrow = mysql_fetch_array().  The do...while loop assigns a value to the $xstr variable 
by taking the name and concatenating the value of $index to the end starting with 0.  So 
the first time through the loop $SubmissionIDStr would have a value of SubmissionID0 the 
next time through it would be SubmissionID1 and so forth.
*/

do {

$registered_id_numStr = registered_id_num.$index;
$team_nameStr = team_name.$index;
    $pointsStr = points.$index;


//This section would print the values onto the screen one record per row

printf("<tr><td><input type=hidden name=%s value=%s>%s</td>
<td><input type=text name=%s value=%s size='5'></td></tr>\n", 
$registered_id_numStr, $row_points["registered_id_num"], $row_points["team_name"], $pointsStr, $row_points["points"]);


//Increase counter values by 1 for each loop

$index++;
$index_count++;

} while ($row_points = mysql_fetch_array($points));

// I also had to create an index count to keep track of the total number of rows.

echo "<INPUT TYPE=hidden NAME=counter VALUE=$index_count>\n";
echo "<INPUT TYPE=hidden NAME=goto VALUE='1'>\n";

echo "<INPUT TYPE=submit></form>\n";
 echo "</table>";

?>

Any help would be greatly appreciated.

Answer 1

You are doing it right - I don't know of any better approach for your case than running update in for loop. What you should do is to enclose this in a transaction:

mysql_query("start transaction");
for ($index = 0; $index <= $index_count; $index++) {
     ...
     $sql = "UPDATE cam_registered_tbl SET points='$pointsvalue',wins='$winsvalue',"."losses='$lossesvalue' WHERE registered_id_num='$registered_id_numvalue'";
     $result = mysql_query($sql);
     if (!$result) { // you possibly should do some error checking
          mysql_query("rollback"); // cancel the transaction
          //print error
          exit(0); 
     }
     ...
}
mysql_query("commit"); // commit the transaction

If you don't use the transaction, you might end up with just some of the records updated, which will leave the database in inconsistent state. Transaction is very important here - with it, all of the records are updated, or none.

Make sure you use the InnoDB engine, in MyISAM engine the transactions do not work.

Answer 2

I didn't read the whole code, but if you have multiple records and you wish to update the same field (with the same value), you can achieve it like this:

UPDATE mytable SET filed = '$value' WHERE id IN (1,2,3,4,5)

if you have an array with ids, you can do it like this:

$ids = implode(',',$array_ids);
UPDATE mytable SET field = '$value' WHERE id IN ('$ids')

BUT If the values are different for each id, just run a loop that updates values for each row.