语法sql语句问题

Question

我创建了一个函数,它不起作用.在盯着它看了15分钟后尝试不同的方式,我无法让它工作.谁能告诉我我的语法有什么问题？变量$user_id是一个数字,$input是一个字符串.我知道mysql已被弃用,这是我正在努力的事情.我只是想知道sql有什么问题,因为毕竟它是一个sql问题.

function insert_what_i_do( $user_id, $input) 
{
    if (mysql_result(mysql_query("SELECT `user_id` FROM `profile` WHERE `user_id` = $user_id"), 0) !== 1) 
    {
        mysql_query("INSERT INTO `profile` (user_id, what_i_do) VALUES ($user_id, '$input')");    
    } 
    else 
    {
        mysql_query("UPDATE `profile` SET `what_i_do` = '$input' WHERE `user_id` =  $user_id");
    }
};

Answer 1

这很简单MySQL,请仔细看看我在那里做了什么,不建议再使用它mysql_*,因为它们已被弃用.注意引用$input？

<?php
    function insert_what_i_do( $user_id, $input) {
        $input = mysql_real_escape_string($input);
        $query = mysql_query("SELECT `user_id` FROM `profile` WHERE `user_id` = '".(int)$user_id."'");
        $num = mysql_num_rows($query);
        if($num) {
            $query = mysql_query("UPDATE `profile` SET `what_i_do` = '".$input."' WHERE `user_id` =  '".(int)$user_id."'");
        } else {
            $query = mysql_query("INSERT INTO `profile` (`user_id`, `what_i_do`) VALUES ('".(int)$user_id."', '".$input."')");
        }
    }
?>

您需要学习使用PDO:

<?php
    $db = new PDO('mysql:host=localhost;dbname=testdb;charset=UTF-8', 'username', 'password', array(PDO::ATTR_EMULATE_PREPARES => false, PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION));
    function insert_what_i_do( $user_id, $input) {
        global $db;
        $stmt = $db->query("SELECT `user_id` FROM `profile` WHERE `user_id` = :user_id");
        $stmt->execute(array(':user_id' => $user_id));
        $num = $stmt->rowCount();
        if($num) {
            $stmt = $db->query("UPDATE `profile` SET `what_i_do` = :input WHERE `user_id` = :user_id");
            $stmt->execute(array(':user_id' => $user_id, ':input' => $input));
        } else {
            $stmt = $db->query("INSERT INTO `profile` (`user_id`, `what_i_do`) VALUES (:user_id, :input)");
            $stmt->execute(array(':user_id' => $user_id, ':input' => $input));
        }
    }
?>