在查询中使用PHP变量时MySQL错误1064 - MySQL error 1064 while using PHP variables in query

MySQL error 1064 while using PHP variables in query

本文关键字：MySQL 错误 1064 变量 PHP 查询 | 更新日期: 2023-09-27

<?php
    session_start();
    $con = mysqli_connect("localhost","root","12369","medical");
    $data1 = $_SESSION["symp1"];
    $data2 = $_SESSION["symp2"];
    $data3 = $_SESSION["symp3"];
    $data4 = $_SESSION["symp4"];
    $finalData = implode(' ', array($data1, $data2, $data3, $data4));
    $userinput = $_REQUEST["answerswer"];
    $dname=$_SESSION["dname"];
    $dname = str_replace(' ', '_', $dname);
    echo $dname."  <br>";
    $sql = " UPDATE diseases SET UserInput = $finalData WHERE Name =   $dname ";
    if($userinput=='yes'){  
        if(mysqli_query($con,$sql)){
            echo "Values inserted";
            $_SESSION["info"] = "yes";
            header('Location: http://localhost/medical/last.php');
    }else{
            echo mysqli_errno($con);
            $_SESSION["info"] = "no";
            //header('Location: http://localhost/medical/last.php');
    }
   }
?>

我得到错误1064?我已经阅读了类似问题的答案，但我的代码不起作用。我的表模式是:

CREATE TABLE IF NOT EXISTS `diseases` (
  `ID` int(50) NOT NULL AUTO_INCREMENT,
  `Name` varchar(255) NOT NULL,
  `Symptoms` varchar(255) NOT NULL,
  `Medicines` varchar(255) NOT NULL,
  `Description` varchar(255) NOT NULL,
  `Tags` varchar(255) NOT NULL,
  `UserInput` varchar(255) NOT NULL,
  PRIMARY KEY (`ID`)
)

我的代码有什么问题?由于

变化:

$sql = " UPDATE diseases SET UserInput = $finalData WHERE Name =   $dname ";

$sql = "UPDATE `diseases` SET `UserInput` = '$finalData' WHERE `Name` = '$dname'";

在包含字符串的变量周围添加单引号。在列和表周围添加反引号以防止mysql保留字错误

使用mysqli_prepare做以下事情会更好:

$stmt = mysqli_prepare($con, "UPDATE `diseases` SET `UserInput` = ? WHERE `Name` = ?");
mysqli_stmt_bind_param($stmt, "ss", $finalData, $dname);
mysqli_stmt_execute($stmt);

正如错误消息所述，您的SQL语法中有错误:

MySQL Error 1064: You have a Error in your SQL syntax

用单引号括住你的数据，你就可以开始了。此外，Name在MySQL中是一个保留关键字。您仍然可以在查询中使用它，但是您应该考虑用反号转义表名:

$sql = " UPDATE diseases SET `UserInput` = '$finalData' WHERE `Name` = '$dname' ";

在数据周围添加单引号:

 $sql = " UPDATE diseases SET UserInput = '$finalData' WHERE Name =   '$dname' ";

或者最好使用预处理语句