PHP mysql search multiple tables using a keyword

Question

I have three tables in my database which are:

messages
topics
comments

Each of these tables has two fields called \'content\' and \'title\'

Answer 1

Html Search form:

<div class="header_top_right">
    <form action="search.php" method="GET" class="search_form">
        <input type="text" placeholder="Text to Search.." name="search">
        <input type="submit" class="btn btn-default" value="">
    </form>
</div>

Search.php:

<?php
    if (isset($_GET['search']) || !empty($_GET['search'])) {
        $search = mysqli_real_escape_string($db->link, $fm->validation($_GET['search']));
    }
    else{
        header("Location:404.php");
    }
?>
<?php
    $query = "SELECT * FROM news_post WHERE title LIKE '%$search%' OR body LIKE '%$search%' OR tags LIKE '%search%'";
    $post = $db->select($query);
    if ($post) {
        while ($result = $post->fetch_assoc()) {
            echo"Database data like, $result['title']";
        }
    }
    else{
        echo "result Not found";
    }

include database.php in search.php

class Database{
    public function select($query){
        $result = $this->link->query($query) or die($this->link->error.__LINE__);
        if($result->num_rows > 0){
            return $result;
        }
        else {
            return false;
        }
    }
}
$db = new Database();

Answer 2

Two search in other tables you use:

SELECT `categories`.`title`, `posts`.`title` WHERE `categories`.`title` LIKE {$a} OR `posts`.`title` LIKE {$a}

The CATEGORIES and POSTS are tables of your database.

Answer 3

$query = "(SELECT content, title, 'msg' as type FROM messages WHERE content LIKE '%" . 
           $keyword . "%' OR title LIKE '%" . $keyword ."%') 
           UNION
           (SELECT content, title, 'topic' as type FROM topics WHERE content LIKE '%" . 
           $keyword . "%' OR title LIKE '%" . $keyword ."%') 
           UNION
           (SELECT content, title, 'comment' as type FROM comments WHERE content LIKE '%" . 
           $keyword . "%' OR title LIKE '%" . $keyword ."%')";

mysql_query($query);

So, you are getting result from all of the three tables, and you can identify which row came from which table by looking at its type value.

Answer 4

What you are probably looking for is the UNION command:

SELECT id, 'messages' as 'table' FROM messages 
  WHERE content LIKE '%keyword%' 
    OR title LIKE '%keyword%'
UNION
SELECT id, 'topics' as 'table' FROM topics
  WHERE content LIKE '%keyword%' 
    OR title LIKE '%keyword%'
UNION
SELECT id, 'comments' as 'table' FROM comments
  WHERE content LIKE '%keyword%' 
    OR title LIKE '%keyword%'