如何按匹配关键字数量的顺序显示结果？

Question

感谢youtube上的精彩视频,如果你愿意,你可以在这里访问,我能够创建一个php搜索引擎.以下是代码:

<?php


//connected to DB

      foreach (array('questioncontent') as $varname) {
        $questioncontent = (isset($_GET[$varname])) ? $_GET[$varname] : '';
      }

?>

<form action="previousquestions.php" method="get">
      <p>Search: <input type="text" name="questioncontent" value="<?php echo $questioncontent; ?>" /></p>
      <p><input id="searchquestion" name="searchQuestion" type="submit" value="Search" /></p>
      </form>

<?php 

if (isset($_GET['searchQuestion'])) {

$searchquestion = $questioncontent;
$terms = explode(" ", $searchquestion);

              $questionquery = "SELECT * FROM Question WHERE ";

              foreach ($terms as $each){
               $i++;   

               if ($i == 1){
               $questionquery .= "QuestionContent LIKE '%$each%' ";
          } else{
               $questionquery .= "OR QuestionContent LIKE '%$each%' ";

              }

          }

      $questionnum = mysql_num_rows($questionresult = mysql_query($questionquery));

        else if($questionnum !=0){

      $output = "";
$output .= "
    <table border='1'>
      <tr>
      <th>Question</th>
      </tr>
";
        while ($questionrow = mysql_fetch_array($questionresult)) {
$output .= "
      <tr>
      <td>{$questionrow['QuestionContent']}</td>
      </tr>";
        }
        $output .= "        </table>";

        echo $output;

  }

}

  mysql_close();

?>

现在我有一个问题,如果有可能,可以搜索搜索结果.让我们在数据库中说我有这3个语句:

My name
My name is Mayur Patel
My name is Patel

现在让我说我在搜索框中输入"Mayur Patel",我想要对结果进行排序,以便它首先显示包含所有这些关键字的任何行,然后在显示所有这些行之后显示这些行其中包含部分数量的关键字(逐个敲掉关键字),以便搜索结果将按以下顺序显示:

My name is Mayur Patel (all keywords match in this phrase)
My name is Patel (2 keywords match this phrase which are 'name' and 'Patel')
My name (1 keyword match this phrase which is 'name')

我想知道我是否可以根据数据库中短语内匹配的关键字数量来订购搜索结果？

Answer 1

目前,您在代码中构建的查询在完成后看起来像这样:

SELECT * FROM Question WHERE
QuestionContent LIKE '%name%'
OR QuestionContent LIKE '%Mayur%'
OR QuestionContent LIKE '%Patel%'

要获得您要查找的结果,您可以添加如下所示的排序子句,该子句将以类似的方式从关键字列表中生成:

ORDER BY
IF(QuestionContent LIKE '%name%',1,0)+
IF(QuestionContent LIKE '%Mayur%',1,0)+
IF(QuestionContent LIKE '%Patel%',1,0) DESC

基本上它通过说匹配关键字来计算匹配的关键字数量,为关键字计数贡献一个,否则贡献0.因此最终,这将产生3,2,1作为计数,并按降序排序DESC因此,首先显示具有最大匹配关键字数量的条目.

演示:http://www.sqlfiddle.com/#!2/eaabc/2

编辑:正如所承诺的,这里有一种在PHP代码中实现的方法:

$questionquery = "SELECT * FROM Question WHERE ";
foreach ($terms as $each) {
    $i++;   

    if ($i == 1){
        $questionquery .= "QuestionContent LIKE '%$each%' ";
    } else {
        $questionquery .= "OR QuestionContent LIKE '%$each%' ";
    }
}

$questionquery .= " ORDER BY ";
$i = 0;
foreach ($terms as $each) {
    $i++;

    if ($i != 1)
        $questionquery .= "+";
    $questionquery .= "IF(QuestionContent LIKE '%$each%',1,0)";
}
$questionquery .= " DESC";