php比较一组版本号大小，输出最新版本号

针对mysql无法正确比较0.0.0类型的版本号，有多个解决方案，如果是单文件可以根据时间判断最新，多文件可以加一个字段is_new;

也可以查出后比较版本大小，下面是php方法

<?php
$array=array('1.0.1','1.1.0','1.2.6','2.1.1','1.5.16','3.1.0','2.2.3','2.2.5','2.2.4','1.5.1','1.9.31');
$newarray = array();
foreach ($array as  $value) {
    $newarray[] = explode('.',$value);
}

$max = $newarray[0][0];
foreach ($newarray as  $v){
        if($v[0]>$max){
            $max = $v[0];
        }
}

foreach ($newarray as $k=> $vl){
    if($vl[0] != $max){
        unset($newarray[$k]);
    }
}

$max = $newarray[0][1];
foreach ($newarray as  $v){
        if($v[1]>$max){
            $max = $v[1];
        }
}

foreach ($newarray as $k=> $vl){
    if($vl[1] != $max){
        unset($newarray[$k]);
    }
}

$max = $newarray[0][2];
foreach ($newarray as $k=> $v){
        if($v[2]>$max){
            $max = $v[2];
        }
}

foreach ($newarray as $k=> $vl){
    if($vl[2] != $max){
        unset($newarray[$k]);
    }
}

foreach ($newarray as  $ve) {
    $ay = implode('.',$ve);
}
var_dump($ay);