用户输入多个表单 fiields 以通过 php 从 mysql 表中检索相关记录 - User Inputting multiple form fiields to retrieve related records from mysql table through php

User Inputting multiple form fiields to retrieve related records from mysql table through php

<html>
    <form action="search_book.php" method="post">
        Title:<input type="text" name="title"><br>
        Author:<input type="text" name="author"><br>
        Price of Book:<input type="text" name="price"><input type="radio"    name="radio" id="less"><Label for="less">Less Than</label><input type="radio" name="radio" id="more"><label for ="more">More Than</label<<br>
        <input type="submit" value="Search">
    </form>
</html>

当用户按标题、作者或价格(html 表单字段(搜索 mysql 表中的记录时，我使用了 if/else if 语句和 post 函数。我的 if/else if 语句基于用户一次输入一个表单字段：

if($_POST['title']!="" && $_POST['title']!=" "){
    $title=$_POST['title'];
    $query=mysqli_query($con,"SELECT * from book where Title='$title'");
} else if($_POST['author']!=""&& $_POST['author']!=" "){
    $title=$_POST['author'];
    $query=mysqli_query($con,"SELECT * from book where Author='$author'");
} else if($_POST['price']!="" && $_POST['price']!=" "){
    $title=$_POST['price'];
    $query=mysqli_query($con,"SELECT * from book where Price='$price'");
}

我现在需要把它提升到一个新的水平，想知道：

如果用户输入两个或三个字段而不仅仅是一个字段，我如何检索表记录(例如，作者和价格或作者和标题(
在"价格"文本字段附近，我需要添加两个单选按钮，这将允许用户检查小于或大于他在文本框中输入的价格

   // Use the Below code it will work for all
   $condition=""; 
   if(isset($_POST) && !empty($_POST)) { 
     if(trim($_POST['title'])!="") {
        $condition.="Title='".$_POST['title']."' AND "; 
     }
    if(trim($_POST['author'])!="") {
      $condition.="Author='".$_POST['author']."' AND "; 
    }
    if(trim($_POST['price'])!="") {
       $condition.="Price='".$_POST['price']."' AND "; 
    }
      // remove last AND 
      if($condition!="") {
          $condition=" WHERE ".substr($condition,0,-5); 
      }
     $query=mysqli_query($con,"SELECT * from book".$condition); 
  }

它会工作