搜索功能:错误

Question

我不知道如何改正这些错误，有人能帮我吗？

search.php

Notice: Undefined index: submit in C:\wamp\www\i-document\search.php on line 12
Notice: Undefined index: search in C:\wamp\www\i-document\search.php on line 13

单击“搜索”后：

Notice: Undefined variable: x in C:\wamp\www\i-document\search.php on line 39
Notice: Undefined variable: construct in C:\wamp\www\i-document\search.php on line 41

谢谢。

代码：

<?php

//Get data

$button = $_GET['submit'];
$search = $_GET['search'];

if (!$button)    echo "You didn't submit a keyword."; else {    if (strlen($search)<=1)
      echo "Search term too short";    else    {
      echo "You searched for <b>$search</b><hr size='1'>";

      //connect to database
      mysql_connect("localhost","root","");
      mysql_select_db("idoc");


            //explode search term
            $search_exploded = explode(" ",$search);

            foreach($search_exploded as $search_each);
            {

                //Construct Query

                $x++;
                if ($x==1)
                   $construct .= "file_name LIKE '%$search_each%'";
                else
                   $construct .= " OR file_name LIKE '%$search_each%'";

            }


      $construct = "SELECT * FROM document WHERE $construct";
      //echo out construct

     // $construct = "SELECT * FROM document WHERE $construct";
     $run = mysql_query($construct);

     $foundnum = mysql_num_rows($run);

     if ($foundnum==0)
        echo "No results found";
     else
     {
        echo "$foundnum results found!<p>";

        while ($runrows = mysql_fetch_assoc($run))
        {
         //Get data
         $ref = $runrows['file_ref'];
      $filename = $runrows['file_name'];    $owner = $runrows['owner'];
         $url = $runrows['url'];
         echo "
        <table>   <tr>
    <td> $ref </td>
    <td> $filename </td>
    <td> $owner </td>
    <td><a href='$url'>$url</a></td>
      </tr>    </table>
         ";
        }

     }
  } }
?>

<form id="form1" method="GET" action="search.php">
  <table width="446" height="135" border="1" align="center">
    <tr>
      <td height="31" colspan="2" align="center" valign="middle" bgcolor="#990000">
        <span class="style1 style2">
          Search :
        </span>
      </td>
    </tr>
    <tr>
      <td width="374" height="96" align="center" valign="middle" bgcolor="#990000">
        <span class="style1 style2">
          <label>
            <div align="left">
              Keyword :
              <input name="search" type="text" id="search" size="40" />
            </div>
          </label>
        </span>
        <td width="56" align="center" valign="middle" bgcolor="#990000">
          <div align="left">
            <input type = "submit" name="submit" value="search" />
          </div>
      </td>
    </tr>
  </table>
</form>

Answer 1

在处理未知数组时，应该在读取数组键之前测试它是否存在。在您的情况下，错误消息显示提交和搜索都不存在。

在读取数组键之前，使用isset或array_key_exists检查数组键是否存在：

// setting default values
$button = '';
$search = '';

// assigning GET parameter values if existing
if (isset($_GET['submit'])) {
    $button = $_GET['submit'];
}
if (isset($_GET['search'])) {
    $search = $_GET['search'];
}

您还可以将conditional operator cond-expr ? true-expr : false-expr用于更简洁的表示法：

$button = isset($_GET['submit']) ? $_GET['submit'] : '';
$search = isset($_GET['search']) ? $_GET['search'] : '';

Answer 2

这意味着在表单被发送之前，$_GET不包含索引'submit‘。您可以使用isset()禁用通知错误呈现或添加条件。

在尝试递增和连接未定义的变量之后。

Answer 3

foreach($search_exploded as $search_each);
{

    //Construct Query

    $x++; // this is bad practice because you didn't initialize the $x var before your foreach
    if ($x==1)
        $construct .= "file_name LIKE '%$search_each%'"; //this also "could" cause problems because you didn't define the $construct in the higher scope so that it "might" not be accessable from outside the if statement. BUT sometimes this works
    else
        $construct .= " OR file_name LIKE '%$search_each%'";

}

这是php在这里给你的两个“通知”：

Notice: Undefined variable: x in C:\wamp\www\i-document\search.php on line 39

Notice: Undefined variable: construct in C:\wamp\www\i-document\search.php on line 41