PHP＆Mysql數據庫更新問題

Question

由於某些原因，當我將php代碼從mysql更改為mysqli時，一切都搞砸了。

例如，當用戶輸入一個等級時，我的mysql表通過輸入一個新行並更新正確的行來更新兩次。 我想知道如何解決此問題，使其僅更新新行並檢查是否沒有行輸入？

PHP代碼

// function to insert rating
function rate(){
    $dbc = mysqli_connect ("localhost", "root", "", "sitename");
    $text = strip_tags($_GET['rating']);
    $update = "update vote set counter = counter + 1, value = value + ".$_GET['rating']."";

    $result = mysqli_query($dbc,$update); 
    if(mysqli_affected_rows() == 0){
        $insert = "insert into vote (counter,value) values ('1','".$_GET['rating']."')";
        $result = mysqli_query($dbc,$insert); 
    }
}

舊的PHP代碼

// function to insert rating
function rate(){
    $text = strip_tags($_GET['rating']);
    $update = "update vote set counter = counter + 1, value = value + ".$_GET['rating']."";

    $result = mysql_query($update); 
    if(mysql_affected_rows() == 0){
        $insert = "insert into vote (counter,value) values ('1','".$_GET['rating']."')";
        $result = mysql_query($insert); 
    }
}

Answer 1

怎么樣

if (mysqli_affected_rows($dbc) ==0){

Answer 2

相反，您應該合並這兩個語句。 這將要求您具有一個主鍵，可能名為id。

// function to insert rating
function rate() {
    $dbc = mysqli_connect ("localhost", "root", "", "sitename");
    $text = strip_tags($_GET['rating']);
    $update = sprintf('INSERT INTO vote SET
                       id = 1,
                       counter = 1,
                       value = %1$d
                       ON DUPLICATE KEY UPDATE
                       counter = counter + 1,
                       value = value + %1$d',
                       $text);
    mysqli_query($dbc,$update); 
}