如何在不同的數據庫表中搜索數據？

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我想在不同的數據庫表中搜索數據？如何在不同的數據庫表中搜索數據？

例如，我輸入像「演示」一個字，的onclick「搜索」按鈕，比顯示DATAS涉及從「產品」表和「製品」表中的「演示」字。

所以，我怎麼寫SQL語句？

順便說一句，我使用PHP和MySQL。

來源

2013-05-28 user2089630

你甚至首先搜索什麼？「LIKE」的東西？ –

至少你需要嘗試一次，顯示代碼.. –

不僅是代碼，而且表結構。 –

您可以查詢像它並不適用於你開始，你還沒有顯示你的表結構，列的任何imformation。所以，下面就是我的猜測

SELECT * FROM article a 
INNER JOIN product p 
ON p.id = a.product_id 
WHERE 
a.article LIKE "%demo%" 
OR 
p.title LIKE "%demo%";

您可以嘗試UNION ALL

SELECT * FROM article a 
a.article LIKE "%demo%" 

UNION ALL 

SELECT * FROM product p 
p.title LIKE "%demo%";

不過可以肯定的是，他們應該有相同的列數。瞭解更多關於UNION here

下面是一些代碼，我已經賜給開始學習它是如何工作

<?php 
    mysql_connect("localhost", "root", "") or die("Error connecting to database: ".mysql_error()); 
    /* 
     localhost - it's location of the mysql server, usually localhost 
     root - your username 
     third is your password 

     if connection fails it will stop loading the page and display an error 
    */ 

    mysql_select_db("your_database") or die(mysql_error()); 
    /* your_database is the name of database we've created */ 
?> 

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
    <title>Search results</title> 
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
    <link rel="stylesheet" type="text/css" href="style.css"/> 
</head> 
<body> 
<?php 
    $query = $_GET['query']; 
    // gets value sent over search form and in your case it is demo 

    $min_length = 3; 
    // you can set minimum length of the query if you want 

    if(strlen($query) >= $min_length){ // if query length is more or equal minimum length then 

     $query = htmlspecialchars($query); 
     // changes characters used in html to their equivalents, for example: < to &gt; 

     $query = mysql_real_escape_string($query); 
     // makes sure nobody uses SQL injection 

     $raw_results = mysql_query("SELECT * FROM article a INNER JOIN product p 
        ON p.id = a.product_id WHERE (`title` LIKE '%".$query."%') OR (`text` LIKE '%".$query."%')") or die(mysql_error()); 

     // * means that it selects all fields, you can also write: `id`, `title`, `text` 
     // articles is the name of our table 

     // '%$query%' is what we're looking for, % means anything, for example if $query is Hello 
     // it will match "demo", "here demo", "demohere", if you want exact match use `title`='$query' 
     // or if you want to match just full word so "gogohello" is out use '% $query %' ...OR ... '$query %' ... OR ... '% $query' 

     if(mysql_num_rows($raw_results) > 0){ // if one or more rows are returned do following 

      while($results = mysql_fetch_array($raw_results)){ 
      // $results = mysql_fetch_array($raw_results) puts data from database into array, while it's valid it does the loop 

       echo "<p><h3>".$results['title']."</h3>".$results['text']."</p>"; 
       // posts results gotten from database(title and text) you can also show id ($results['id']) 
      } 

     } 
     else{ // if there is no matching rows do following 
      echo "No results"; 
     } 

    } 
    else{ // if query length is less than minimum 
     echo "Minimum length is ".$min_length; 
    } 
?> 
</body> 
</html>

來源

2013-05-28 05:57:01 Yogus

感謝您的回覆。我真正的問題是表'產品'和'文章'沒有外鍵連接，它們是相互依賴的。 – user2089630

所以你的問題與你上面提出的問題不同。這是數據庫設計不佳的簡單問題。 – Yogus

@ user2089630與UNION concept.Accept上面閱讀的答案，並給予投票支持它是否適合你:) – Yogus

如何在不同的數據庫表中搜索數據？

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