PHP代碼從多個表中搜索在DATABSE

Question

我有我的數據庫三種不同的表，我需要從所有表中搜索內容，但沒有工作，因爲它有不同的屬性

這裏是我的表結構

表1名>>博文

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

表2名>> forumnew

| fid | ftitle | fbody   | user | 

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

表3名>>下載

| did | file  | disc   | type  | 

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

我用這個PHP代碼從單個表中選擇

<?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

你這裏有幾個選項：

• 使用三個單獨的查詢
• 使用UNION

一個例子我的頭的頂部，你怎麼能這樣做工會是這樣的：

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 

訣竅是選擇從所有三個表中的數據轉換爲一組具有相同名稱的列。