php – 根据另一个值更新最小值 – MySql

我有一组信息,我将其爆炸为id,代码和数字.

list ($id,$code,$num) = explode("~",$data);

我需要根据最小num的唯一代码将它更新为MysqL

假设我的前3个请求看起来像

id = 9267399
code = 5D:148
num = 64

id = 9267398
code = 5D:186
num = 71

id = 9267397
code = 5D:122
num = 93

然后我的第4,第5个请求有重复的代码5D：148,具有不同的id和num.

id = 9267402
code = 5D:148
num = 22

id = 9267563
code = 5D:148
num = 5

现在我需要找到重复代码的min(num)并将该记录更新回MysqL.我的查询应该是这样的

$sql = "UPDATE table SET id = '9267398',num = '71' WHERE code = '5D:186' ";
$sql = "UPDATE table SET id = '9267397',num = '93' WHERE code = '5D:122' ";
$sql = "UPDATE table SET id = '9267563',num = '5' WHERE code = '5D:148' ";

这里5D：148有3个请求,其中min(num)是5.

我试过找到重复的代码

$temp = array();
foreach ($code as $c) {
    isset($temp[$c]) or $temp[$c] = 0;
    $temp[$c] ++;
}
var_dump($temp); 

这给了我

array(3) {["5D:148"]=> int(3) ["5D:186"]=> int(1) ["5D:122"]=> int(1)}  

我被困在这里如何找到min(num)并根据它运行我的更新查询

最佳答案

循环遍历数组并检查num是否低于前一个数字.

$data数组的示例：

$data = array(
[0] => array('id' => 9267399,'code' => '5D:148','num' => 64),[1] => array('id' => 9267398,'code' => '5D:186','num' => 71)
);

–

PHP

$array_to_add = array();

foreach($data AS $val) {

    if(array_key_exists($val['code'],$array_to_add)) {

        if((int) $val['num'] < (int) $array_to_add[$val['code']]['num']) { // Check if num is lower than the prevIoUs one
            $array_to_add[$val['code']] = $val; // If yes,overwrite code key with new values
        } 

    } else {

        $array_to_add[$val['code']] = $val; // Add values to array if code doesn't exist in array_to_add

    }

}

var_dump($array_to_add); // ARRAY TO ADD IN DATABASE

foreach($array_to_add AS $val) {

    MysqL_query("UPDATE table SET id = ".MysqL_real_escape_string($val['id']).",num = ".MysqL_real_escape_string($val['num'])." WHERE code = '".MysqL_real_escape_string($val['code'])."' ");

}

?>

提示：查看PDO和MysqLi以更好地使用mySQL查询.