php - PHP删除SQL查询不起作用

<?php
    include('session.php');
?>

<?php
    $conn = new mysqli("127.0.0.1","root","","foo");
    if ($conn->connect_errno) {
        echo "Failed to connect to MySQL: (" . $conn->connect_errno . ") " .         $conn->connect_error;
    }
    $sew = $_SESSION['login_user'];
    $a = $_GET["en"];
    $l = 1;
    $d = -1;

    if($a == 1)
    {
        $sqlw = " INSERT into dlkeuser VALUES('$a','$sew')" ;

        if ($conn->query($sqlw) === FALSE)
        {
            echo "you have already disliked the song";
        }
        else
        {
        //query1
            $sql = " DELETE FROM lkeuser WHERE userid = '$sew' AND songid = '$a' ";

        //query2
            $sql = "UPDATE liking
            SET count = count - 1 ";

            if ($conn->query($sql) === TRUE) {
                echo "you disliked the song";
            }
            else {
                echo "Error: " . $sql . "<br>" . $conn->error;
            }
        }

在此php代码段中，query1不起作用，而query 2很好。

我试图针对用户i / p（dlkeuser(dislike)）在$_GET["en"]表中插入（songid，userid），并从lkeuser(like)表中删除记录（songid，userid）（如果存在）。 （songid，userid）对是此处的复合主键。 count是歌曲的喜欢/不喜欢的网络。

最佳答案

让我们尝试一下

它会工作

<?php
    include('session.php');
?>

<?php
    $conn = new mysqli("127.0.0.1","root","","foo");
    if ($conn->connect_errno) {
       echo "Failed to connect to MySQL: (" . $conn->connect_errno . ") " .           $conn->connect_error;
    }
    $sew = $_SESSION['login_user'];
    $a = $_GET["en"];
    $l = 1;
    $d = -1;

    if($a == 1)
    {
    $sqlw = " INSERT into dlkeuser VALUES('$a','$sew')";

        if ($conn->query($sqlw) === FALSE)
        {
            echo "you have already disliked the song";
        }
        else
        {
        //query1
            $sql  = " DELETE FROM lkeuser WHERE userid = '$sew' AND songid = '$a' " ;

        //query2
            $sql1 = "UPDATE liking
            SET count = count - 1 ";

            if ($conn->query($sql) === TRUE) {
                echo "deleted the song";
            }

            if ($conn->query($sql1) === TRUE) {
                echo "you disliked the song";
            }
            else {
                echo "Error: " . $sql . "<br>" . $conn->error;
            }
        }