PHP mysql 页面查看计数器

Question

我尝试制作一个简单的页面浏览计数器。每次刷新页面时，数字都会增加+1。

当我在 Phpmyadmin 中执行代码时，一切正常。但在 php 中，计数器被返回，但不增加。我做错了什么？

<?php
$username = "username";
$password = "password";
$hostname = "hostname";
$dbname = "dbname";


// Create connection
$conn = new mysqli($hostname, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
} 

$sql = "UPDATE `Games` SET `Played`= `Played`+1 WHERE 'ID'='3'";

$sql = "SELECT `Played` FROM `Games` WHERE `ID` = 3";

$result = mysqli_query($conn, $sql);

if (mysqli_num_rows($result) > 0) {
// output data of each row
while($row = mysqli_fetch_assoc($result)) {
    echo "" . $row[Played]. "<br>";
}
} else {
echo "0 results";
}

$conn->close();
?>

Answer 1

在 $sql 变量中创建 UPDATE 字符串后，您必须调用 mysqli_query 。您现在所做的只是使用 SELECT 查询字符串覆盖它。

[...]

$sql = "UPDATE `Games` SET `Played`= `Played`+1 WHERE `ID`='3'";

$result = mysqli_query($conn, $sql);

$sql = "SELECT `Played` FROM `Games` WHERE `ID` = 3";

$result = mysqli_query($conn, $sql);

[...]