我有这段代码可以打印出数据库中的列并为我添加“利润”列。 距离的计算方式很复杂，因此是在循环中完成的，而距离到“利润”的转换是在打印出来时完成的。
我想做的是按照“利润”降序打印它们。我相信（但不知道）最好的方法是将它们存储在一个数组中并“将它们排序”然后从那里打印出来。
如何确定将它们粘贴到数组的哪一行？
如何对数组进行排序？
如何循环遍历数组，这样我就无法将它们打印出来？
//display results
// now we retrieve the routes from the db
$query = "SELECT * FROM routes ORDER BY `id`;";
// run the query. if it fails, display error
$result = @mysql_query("$query") or die('<p class="error">There was an unexpected error grabbing routes from the database.</p>');
?>
<tr>
<td style="background: url(http://www.teamdelta.byethost12.com/barbg.jpg) repeat-x top;">
<center><b><font color="#F3EC84">»Matches«</font></b></center>
</td>
</tr>
<tr>
<td style="background: #222222;">
</font>
<table border="0" width="100%"><tr>
<td width="10%"><b><center><b>Player</b></center></b></td>
<td width="10%"><center><b>Base</b></center></td>
<td width="10%"><b>Location</b></td>
<td width="5%"><b>Econ</b></td>
<td width="10%"><b>Distance</b></td>
<td width="10%"><center><b>Profit cred./h</b></center></td>
<td width="40%"><b>Comment</b></td>
<td width="5%"><align="right"><b>Delete</b></align></td>
</tr>
<?
// while we still have rows from the db, display them
while ($row = mysql_fetch_array($result)) {
$dname = stripslashes($row['name']);
$dbase = stripslashes($row['base']);
$dlocation = stripslashes($row['location']);
$dx = stripslashes($row['x']);
$dy = stripslashes($row['y']);
$dgalaxy = stripslashes($row['galaxy']);
$dplanet = stripslashes($row['planet']);
$dcomment = stripslashes($row['comment']);
$did = stripslashes($row['id']);
$decon = stripslashes($row['econ']);
$distance = -1 ;//default
//distance calc
if($dgalaxy == $galaxy)
{//interstellar
if(($dx == $x) && ($dy == $y))
{//inter planitary
if ((floor($planet/10)*10) == (floor($dplanet/10)*10))
{// intra planitary loonar
$distance = abs(fmod($planet,10)-fmod($planet,10))*0.1;
}
else
{// inter planitary
$distance = abs((floor($planet/10)*10)-(floor($planet/10)*10))*0.2;
}
}else
{//interstllar
$distance = round(Sqrt(pow(($dx-$x),2)+pow(($dy-$y),2)));//interstllar
}
}
else
{//intergalatic
if ((floor($galaxy/10)*10) == (floor($dgalaxy/10)*10))
{//intra galactic cluster
$distance = abs(($galaxy-$dgalaxy))*200;
}
else
{//inter galactic cluster
if ($galaxy < $dgalaxy)
{//anti clockwise inter galactic cluster
$distance = (((9-fmod($galaxy,10))*200)+2000+(fmod($dgalaxy,10)*200));
}
else
{//clockwise inter galactic cluster
$distance = (((fmod($galaxy,10))*200)+2000+(fmod(9-$dgalaxy,10)*200));
}
}
}
echo('<tr>
<td width=\'20px\'><center>('.$dname.')</center></td>
<td><center>'.$dbase.'</center></td>
<td><a href="http://delta.astroempires.com/map.aspx?loc='.$dlocation.'">'.$dlocation.'</a></td>
<td>'.$decon.'</td><td>'.$distance.' </td>
<td>'.round(Sqrt(min($decon,$econ))*(1+Sqrt($distance)/75+Sqrt($players)/10)).'</td>
<td>['.$dcomment.']</td>
<td><a href=deleterouteconfirm.php?id='.$did.'>Delete</a></td>
</tr>');
}
?></table><!--display results table-->
我认为最简单的解决方案是对数据库结果进行双重传递。
第一遍将生成每行的“距离”和“利润”值，并将这些行存储到我们将排序的数组中。
第二遍将只是简单地循环第一遍中创建的数组并在正确排序并转义输出后显示它们。
<?php
//display results
// now we retrieve the routes from the db
$query = "SELECT * FROM routes ORDER BY `id`;";
// run the query. if it fails, display error
$result = @mysql_query( "$query" ) or die( '<p class="error">There was an unexpected error grabbing routes from the database.</p>' );
?>
<tr>
<td
style="background: url(http://www.teamdelta.byethost12.com/barbg.jpg) repeat-x top;">
<center><b><font color="#F3EC84">»Matches«</font></b></center>
</td>
</tr>
<tr>
<td style="background: #222222;"></font>
<table border="0" width="100%">
<tr>
<td width="10%"><b>
<center><b>Player</b></center>
</b></td>
<td width="10%">
<center><b>Base</b></center>
</td>
<td width="10%"><b>Location</b></td>
<td width="5%"><b>Econ</b></td>
<td width="10%"><b>Distance</b></td>
<td width="10%">
<center><b>Profit cred./h</b></center>
</td>
<td width="40%"><b>Comment</b></td>
<td width="5%"><align="right"><b>Delete</b></align></td>
</tr>
<?
// while we still have rows from the db, display them
$resultSet = array();
while ( $row = mysql_fetch_array( $result ) )
{
$dname = stripslashes( $row['name'] );
$dbase = stripslashes( $row['base'] );
$dlocation = stripslashes( $row['location'] );
$dx = stripslashes( $row['x'] );
$dy = stripslashes( $row['y'] );
$dgalaxy = stripslashes( $row['galaxy'] );
$dplanet = stripslashes( $row['planet'] );
$dcomment = stripslashes( $row['comment'] );
$did = stripslashes( $row['id'] );
$decon = stripslashes( $row['econ'] );
$distance = -1; //default
//distance calc
if ( $dgalaxy == $galaxy )
{ //interstellar
if ( ( $dx == $x ) && ( $dy == $y ) )
{ //inter planitary
if ( ( floor( $planet / 10 ) * 10 ) == ( floor( $dplanet / 10 ) * 10 ) )
{ // intra planitary loonar
$distance = abs( fmod( $planet, 10 ) - fmod( $planet, 10 ) ) * 0.1;
} else
{ // inter planitary
$distance = abs( ( floor( $planet / 10 ) * 10 ) - ( floor( $planet / 10 ) * 10 ) ) * 0.2;
}
} else
{ //interstllar
$distance = round( Sqrt( pow( ( $dx - $x ), 2 ) + pow( ( $dy - $y ), 2 ) ) ); //interstllar
}
} else
{ //intergalatic
if ( ( floor( $galaxy / 10 ) * 10 ) == ( floor( $dgalaxy / 10 ) * 10 ) )
{ //intra galactic cluster
$distance = abs( ( $galaxy - $dgalaxy ) ) * 200;
} else
{ //inter galactic cluster
if ( $galaxy < $dgalaxy )
{ //anti clockwise inter galactic cluster
$distance = ( ( ( 9 - fmod( $galaxy, 10 ) ) * 200 ) + 2000 + ( fmod( $dgalaxy, 10 ) * 200 ) );
} else
{ //clockwise inter galactic cluster
$distance = ( ( ( fmod( $galaxy, 10 ) ) * 200 ) + 2000 + ( fmod( 9 - $dgalaxy, 10 ) * 200 ) );
}
}
}
$row['distance'] = $distance;
$row['profit'] = round( Sqrt( min( $decon, $econ ) ) * ( 1 + Sqrt( $distance ) / 75 + Sqrt( $players ) / 10 ) );
$resultSet[] = $row;
}
// Perform custom sort
usort( $resultSet, 'sorter' );
function sorter( $a, $b )
{
if ( $a['profit'] == $b['profit'] ) return 0;
return ( $a['profit'] < $b['profit'] ) ? -1 : 1;
}
// Switch to "descending"
array_reverse( $resultSet );
// Output escape the values
$safeForHtml = array_map( 'htmlspecialchars', $resultSet );
foreach( $safeForHtml as $row )
{
echo ( '<tr>
<td width=\'20px\'><center>(' . $row['name'] . ')</center></td>
<td><center>' . $row['base'] . '</center></td>
<td><a href="http://delta.astroempires.com/map.aspx?loc=' . $row['location'] . '">' . $row['location'] . '</a></td>
<td>' . $row['econ'] . '</td>
<td>' . $row['distance'] . ' </td>
<td>' . $row['profit'] . '</td>
<td>[' . $row['comment'] . ']</td>
<td><a href=deleterouteconfirm.php?id=' . $row['id'] . '>Delete</a></td>
</tr>' );
}
?>
</table>
<!--display results table-->
您正在从 MySQL 获取数据。为什么不直接从查询中对结果进行排序？
$query = "SELECT * FROM routes ORDER BY `profit` DESC, `id`;";
编辑：重新阅读您的问题，利润不是一个字段，但您可能想用利润值填充表格，而不是每次都重新计算。
编辑2： 或者，保护你的输出，计算你的利润，将所有内容放入数组中，然后使用以下内容：
$resultArray; //Your array with all your rows plus a profit key-value pair.
$sortedArray = array_msort($resultArray, array('profit'=>SORT_DESC));
// array_msort by cagret at gmail dot com
function array_msort($array, $cols)
{
$colarr = array();
foreach ($cols as $col => $order) {
$colarr[$col] = array();
foreach ($array as $k => $row) { $colarr[$col]['_'.$k] = strtolower($row[$col]); }
}
$params = array();
foreach ($cols as $col => $order) {
$params[] =& $colarr[$col];
$params = array_merge($params, (array)$order);
}
call_user_func_array('array_multisort', $params);
$ret = array();
$keys = array();
$first = true;
foreach ($colarr as $col => $arr) {
foreach ($arr as $k => $v) {
if ($first) { $keys[$k] = substr($k,1); }
$k = $keys[$k];
if (!isset($ret[$k])) $ret[$k] = $array[$k];
$ret[$k][$col] = $array[$k][$col];
}
$first = false;
}
return $ret;
}
这看起来不像是应该在读取时进行的计算，而是应该在写入时进行。
在插入或更新数据库表之前，执行此计算并存储它。
或者将距离列创建为计算列，并在每次修改行时自动更新。
这将使您的查询更快、更易于管理，因为您只需
ORDER BY distance DESC如果上述内容没有吸引力，则将所有结果提取到关联行数组中，然后将复杂的计算填充到
array_map()array_multisort()array_multisort(
array_map(getDistance(...), $resultSet), // get distance for each row
SORT_DESC,
$resultSet
);
// now print out the sorted $resultSet