Php-Code aus mehreren Tabellen in databse suchen

Question

Ich habe drei verschiedene Tabelle in meiner Datenbank, die ich Inhalte von allen der Tabelle suchen, müssen aber nicht funktioniert, weil es verschiedene Attribute

hier ist meine Tabellenstruktur hat

Tabelle 1 Name >> Blogpost

| bid | title  | body   | author | 
|----- |------- |------------- |-------- | 
| 1  | new  | hello new  | you  | 
| 2  | cast  | broadcast  | me  | 
| 3  | hack  | who hack us | you  | 

table2 Name >> forumnew

| fid | ftitle | fbody   | user | 

|----- |------- |------------- |-------- | 
| 1  | new forum | hello new  | you  | 
| 2  | cast me | broadcast  | me  | 
| 3  | hack you | who hack him | us  | 

table3 Name >> Download

| did | file  | disc   | type  | 

|----- |------- |------------- |-------- | 
| 1  | whoweare | hello new  | php  | 
| 2  | cast  | broadcast  | html  | 
| 3  | hack  | who hack us | c++  | 

ich diesen PHP-Code verwenden, um von einzelnen Tabelle wählen

<?php 
if(isset($_GET['postid'])){ 
$search = $_GET['postid']; 


    $output; 

    if(!empty($search)){ 
     $dsn = new DBController(); 
     $dsn->prepare("SELECT * FROM blogpost WHERE title LIKE :search LIMIT 10"); 
     $dsn->bind(':search', '%'.$search.'%'); 
     $dsn->execute(); 
     $output = $dsn->getAll(); 
     $dsn->free(); 
    } 

    if(!is_null($output)): 
     $html = ''; 
     foreach($output as $i => $row){ 
      $id = $row->bid; 
      $title = $row->title; 
      $cont = $row->body; 
      $html .= '<article> <div class="spacer js-gps-track"> 
    <a href="'.$id.'" class="readmore related ret">'.$title.'</a> 
$body 
</div></article>'; 
     } 
     echo $html; 
    else: ?> 
<h5 style="color: #2f2f2f;">No related search found</h5><br/> 
<?php endif; 
}?> 

Answer 1

Sie haben ein paar Optionen hier:

• Verwenden drei separate Abfragen
• Verwenden Sie ein UNION

Ein Beispiel aus der Spitze von meinem Kopf, wie man eine Vereinigung tun können, ist wie folgt:

SELECT 
    * 
FROM (
    (SELECT 'post' AS type, bid AS id, title, body AS description, author AS owner FROM blogpost) AS search_posts 
    UNION 
    (SELECT 'forum' AS type, fid AS id, ftitle AS title, fbody AS description, user AS owner FROM forumnew) AS search_forum 
    UNION 
    (SELECT 'download' AS type, did AS id, file AS title, disc AS description, type AS owner FROM download) AS search_downloads 
) 
WHERE title LIKE :search 
    OR description LIKE :search 

Der Trick ist, Daten aus allen drei Tabellen in einen Satz wählen von Spalten mit dem gleichen Namen.