我收到此错误警告：尝试访问 null 类型值的数组偏移量答案

【问题标题】：I am getting this error Warning: Trying to access array offset on value of type null我收到此错误警告：尝试访问 null 类型值的数组偏移量
【发布时间】：2023-01-10 12:09:40
【问题描述】：

我收到这个错误

警告：尝试在第 15 行的 E:\xampp\htdocs\word-meaning-learn\word-ajax-insert.php 中访问 null 类型值的数组偏移量插入意义数据！

线上的代码有什么问题？ > if($row['bangla_mean'] == $bangla_mean)

<?php
include "config.php";
$bangla_mean = $_POST["bangla_mean"];
$english_mean = $_POST["english_mean"];
$example_mean = $_POST["example_mean"];
$synonym_mean = $_POST["synonym_mean"];

if(isset($bangla_mean)){
  $stmt = $conn->prepare("SELECT bangla_mean FROM wordmeanings_table WHERE bangla_mean=?");
$stmt->bind_param("s",$bangla_mean);
$stmt->execute();
$result = $stmt->get_result();
$row = $result->fetch_array(MYSQLI_ASSOC);

if($row['bangla_mean'] == $bangla_mean){
  $response = "This Bangla meaning already exist!";
  }
 else{
  $stmt = $conn->prepare("INSERT INTO wordmeanings_table (bangla_mean, english_mean, example_mean, synonym_mean) VALUES (?, ?, ?, ?)");
        $stmt->bind_param("ssss",$bangla_mean,$english_mean,$example_mean,$synonym_mean);
      if($stmt->execute()){
        $response = "Inserted the meaning data!";
      }
      else{
        $response = "Something went wrong!";
      }
  }
}

echo $response;
        exit;
?>

【问题讨论】：

摆脱$row['bangla_mean'] == $bangla_mean。如果你得到一个结果，那是真的，因为WHERE bangla_mean=?。
如果 $row 是一个数组，你是说 $row[$bangla_mean]
Warning: Trying to access array offset on value of type null 表示您尝试从中获取数据的数组不是数组，而是 null。看起来您的数据库查询没有给出结果。
@depperm $row 不会将 $bangla_mean 作为索引，除非值和列具有相同的名称。
或者您尝试使用 null 作为索引或大于数组大小的索引来访问数组

标签： php

【解决方案1】：

您的查询为空，您尝试获取“？”的结果，这不符合逻辑。请改为尝试这样做：

if(isset($bangla_mean)){
  $stmt = $conn->prepare("SELECT bangla_mean FROM wordmeanings_table WHERE bangla_mean='$bangla_mean'");
$stmt->bind_param("s",$bangla_mean);
$stmt->execute();
$result = $stmt->get_result();
$row = $result->fetch_array(MYSQLI_ASSOC);

【讨论】：