在ajax中编辑后发出警报

Question

我正在使用ajax实现一个简单的插入和编辑，但是在编辑时它没有显示警报，而在插入时它告诉未定义的索引，尽管我的字段名称与我的数据库中一样

edit.php

<?php
    $connect=mysqli_connect("localhost","root","") or die('Could not connect: '.mysqli_error()); mysqli_select_db($connect,'elearning') or die ('database not found: '.mysqli_error()); 
    $id = $_POST["pageID"]; 
    $text = $_POST["text"]; 
    $column_name = $_POST["column_name"];
    $sql = "UPDATE page SET ".$column_name."='".$text."' WHERE pageID='".$id."'"; 
    if(mysqli_query($connect, $sql)) { echo 'Data Updated'; } 
?>

page.php文件

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<script>
  $(document).ready(function() {
    function fetch_data() {
      $.ajax({
        url: "select.php",
        method: "POST",
        success: function(data) {
          $('#live_data').html(data);
        }
      });
    }
    fetch_data();
    $(document).on('click', '#btn_add', function() {
      var cid = $('#cid').text();
      var name = $('#name').text();
      var icon = $('#icon').text();
      var src = $('#src').text();
      var hint = $('#hint').text();
      var category = $('#category').text();

      $.ajax({
        url: "insert.php",
        method: "POST",
        data: {
          cid: cid,
          name: name,
          icon: icon,
          src: src,
          hint: hint,
          category: category
        },
        dataType: "text",
        success: function(data) {
          alert(data);
          fetch_data();
        }
      })
    });

    function edit_data(id, text, column_name) {
      $.ajax({
        url: "edit.php",
        method: "POST",
        data: {
          pageID: id,
          text: text,
          column_name: column_name
        },
        dataType: "text",
        success: function(data) {
          alert(data);
        }
      });
    }

    $(document).on('click', '.btn_delete', function() {
      var id = $(this).data("id7");
      if (confirm("Are you sure you want to delete this?")) {
        $.ajax({
          url: "delete.php",
          method: "POST",
          data: {
            pageID: id
          },
          dataType: "text",
          success: function(data) {
            alert(data);
            fetch_data();
          }
        });
      }
    });
  });
</script>

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