更新表只设置有输入的列 [英] Update table set only column which have input

问题描述

这是我的问题，我正在开发将数据更新到数据库的应用程序.我的问题是当我将新数据发送到 db 时，如果输入为空，它会用 0 覆盖表中的现有数据.只有当我有一些值时，在我的情况下，输入中的数字才会正确更新.

Hi there here is my problem I'm working on app which update data to db. My problem is when I send new data to db if the input is empty it overwrites the existing data in table with 0. Only if I have some value, in my case numbers in inputs it updates correctly.

如何检查我没有发送的空输入?

How to check empty inputs i don't send them?

<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);

$mysql_host = "localhost";
$mysql_username = "root";
$mysql_password = "";
$mysql_database = "medvedgrad";

// First we create the connection
$pdo = new PDO("mysql:host=".$mysql_host .";dbname=".$mysql_database .";charset=utf8", $mysql_username, $mysql_password);
$pdo->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);  

$data = json_decode(file_get_contents("php://input"));
$zm = $data->zlatni_medvjed;
$ck = $data->crna_kraljica;
$gv = $data->gricka_vjestica;
$dk = $data->dva_klasa;
$fk = $data->fakin;

// Then we prepare, and execute the query
 $stmt = $pdo->prepare("UPDATE `stanje_piva` SET `zlatni_medvjed`=`zlatni_medvjed`+:zm, `crna_kraljica`=`crna_kraljica`+:ck, `gricka_vjestica`=`gricka_vjestica`+:gv, `dva_klasa`=`dva_klasa`+:dk,`fakin`=`fakin`+:fk WHERE `id`=1");


 $stmt->execute(array("zm" => $zm, "ck" => $ck, "gv" => $gv, "dk" => $dk, "fk" =>   $fk));
 ?>

推荐答案

您需要一种方法来仅将非空值包含到数组中并仅更新那些值.

You need a way to include only not-empty values to the array and update only those.

$updateArray = array();
$sqlString = "Update `stanje_piva` SET ";

foreach(['zm' => $zm, 'ck' => $ck, 'gv' => $gv, 'dk' => $dk, 'fk' => $fk] as $key => $value){

    // add to updateArray ONLY IF NOT EMPTY
    if($value != ''){
        // add key/value to updateArray
        array_push($updateArray, $key => $value);

        // append key/value to sql string
        switch($key){
            case 'zm': 
                $sqlString .= "`zlatni_medvjed`=`zlatni_medvjed`+:zm, ";
                break;
            case 'ck': 
                $sqlString .= "`crna_kraljica`=`crna_kraljica`+:ck, ";
                break;
            case 'gv': 
                $sqlString .= "`gricka_vjestica`=`gricka_vjestica`+:gv, ";
                break;
            case 'dk': 
                $sqlString .= "`dva_klasa`=`dva_klasa`+:dk, ";
                break;
            case 'fk': 
                $sqlString .= "`fakin`=`fakin`+:fk, ";
                break;
        }
    }
}

// remove last ', ' from sqlQuery
$sqlQuery = substr($sqlQuery, 0, strlen($sqlQuery)-2);

// add Where clause
$sqlQuery .= " WHERE `id`=1";

// prepare
$stmt = $pdo->prepare($sqlQuery);

// execute
$stmt->execute($updateArray);

忘记准备stmt，补充一下.

edit: forgot to prepare stmt, added that.

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