sidebar.php

<div id="sidebar" class="col-md-4">
    <!-- search box -->
    <div class="search-box-container">
        <h4>Search</h4>
        <form class="search-post" action="search.php" method ="GET">
            <div class="input-group">
                <input type="text" name="search" class="form-control" placeholder="Search .....">
                <span class="input-group-btn">
                    <button type="submit" class="btn btn-danger">Search</button>
                </span>
            </div>
        </form>
    </div>
    <!-- /search box -->

    <!-- recent posts box -->
    <div class="recent-post-container">
        <h4>Recent Posts</h4>
        <?php
          include "config.php";
          $limit=3;

        $sql="SELECT post.post_id,post.title,category.category_name,post.post_date,post.description,post.post_img,post.author,post.category
        FROM post
        LEFT JOIN category ON post.category=category.category_id ORDER BY post_id DESC LIMIT {$limit}";   //view latest post information

          $result=mysqli_query($conn,$sql) or die("Query failed ");
          if(mysqli_num_rows($result) > 0 ){
            while($row = mysqli_fetch_assoc($result)) {
         ?>
        <div class="recent-post">
            <a class="post-img" href="single.php?id=<?php echo $row['post_id'];?>">
                <img src="admin/upload/<?php echo $row['post_img'];?>" alt=""/>
            </a>
            <div class="post-content">
                <h5><a href="single.php?id=<?php echo $row['post_id'];?>"><?php echo $row["title"];?></a></h5>
                <span>
                    <i class="fa fa-tags" aria-hidden="true"></i>
                    <a href='category.php?cid=<?php echo $row["category"];?>'> <?php echo $row["category_name"];?></a>
                </span>
                <span>
                    <i class="fa fa-calendar" aria-hidden="true"></i>
                   <?php echo $row["post_date"];?>
                </span>
                <a class="read-more" href="single.php?id=<?php echo $row['post_id'];?>">read more</a>
            </div>
        </div>
      <?php }
    }
     ?>
    </div>
    <!-- /recent posts box -->
</div>