PHP MySQL - 函数 [英] PHP MySQL - Function

问题描述

我写了一个 PHP 函数，但它在特定点什么都不做.. 我是 php 新手，我的英语不好，很抱歉.

i wrote a PHP Function but it does nothing at a specific point.. im new to php and my english is bad, sorry for that.

<?php
function SQLwriteRecent($id, $title, $link) {
    $con=mysqli_connect("localhost","","","");
    // Check connection
    if (mysqli_connect_errno()) {
      echo "Failed to connect to MySQL: " . mysqli_connect_error();
    }

    $count = mysqli_query($con,"SELECT count FROM recent WHERE sc_stream='$id'");

   if(!isset($count)) {
        try {
            mysqli_query($con,"INSERT INTO recent (title, link, sc_stream, count) VALUES ('$title', '$link', '$id',$count)");
            mysqli_close($con);
            return 1;
        } catch(Exception $e) {
            return 0;
        }
    } else {
        try {
            // ------ SHOW HERE!!!! ------------ //
            mysqli_query($con,"UPDATE recent SET count=$count WHERE sc_stream='$id'");
            mysqli_close($con);
            return 2;
        } catch(Exception $e) {
            return 0;            
        }       
    }


}
?>

代码每次运行直到特定点(我在代码中用 //------ SHOW HERE!!!! ------------//)

the code runs every time until a specific point (i marked it in the code with // ------ SHOW HERE!!!! ------------ //)

在sql表中，目前没有条目.所以我应该创建一个新行

in the sql table, currently there is no entry. so i should create a new row

那个代码有什么问题?！:(

whats wrong with that code?! :(

推荐答案

结合其他人所说的，再看看你所做的事情的逻辑，看起来你有几个基本问​​题:

Combining what other people have said, and looking at the logic of what you're doing, it looks like you have a few fundamental issues:

我调整了一些变量名称，以便更清楚地说明您得到的内容，并在代码中添加了描述问题的注释.

I've tweaked some variable names to make it clearer what you're getting an peppered the code with comments that describe the issues.

我忽略了 SQL 注入问题.

I've ignored the SQL injection issues.

<?php

function SQLwriteRecent($id, $title, $link) {

    $con=mysqli_connect("localhost","","","");

    // Check connection
    if (mysqli_connect_errno()) {
      echo "Failed to connect to MySQL: " . mysqli_connect_error();
    }

    $countQuery = mysqli_query($con,"SELECT count FROM recent WHERE sc_stream='$id'");

    $numberOfRowsReturnedByQuery = mysqli_num_rows($count);

    if ( $numberOfRowsReturnedByQuery > 0 ) {
        $valueOfCountInQuery = $countQuery [0]['count'];
    }

    if( $numberOfRowsReturnedByQuery == 0) {
        try {

            // In this situation it looks like you want to set up a value in "recent" - I.E. you didn't have a record.
            // But think about it for a second - if you had no record in "recent" then how could "$valueOfCountInQuery" possibly be set?

            mysqli_query($con,"INSERT INTO recent (title, link, sc_stream, count) VALUES ('$title', '$link', '$id',$valueOfCountInQuery )"); // makes no sense to use "$valueOfCountInQuery" - maybe you mean "0" (zero)
            mysqli_close($con);
            return 1;
        } catch(Exception $e) {
            return 0;
        }
    } else {
        try {

            // In this situation it looks like you want to update the value in "recent" - I.E. you DID have a record and you want to change it.
            // But think about it for a second - the value of "$valueOfCountInQuery" is the value that you got from "count" on "recent".  You are setting it to the same value that's already in there!

            // ------ SHOW HERE!!!! ------------ //
            mysqli_query($con,"UPDATE recent SET count=$valueOfCountInQuery WHERE sc_stream='$id'"); // redundant

            mysqli_close($con);
            return 2;
        } catch(Exception $e) {
            return 0;            
        }       
    }
}
?>

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