mysql中的類別顯示一次

Question

我有一些數據在數據庫中，它的輸出與ORDER BY category，我想知道如何只顯示一次類別？

$SQL = mysql_query("SELECT id,name,category FROM table ORDER BY category,id"); 

所以我的腳本遍歷整個表並按類別名排序所有項目。

我希望能夠以顯示類別名稱，一旦如此，則其餘值可以落在該類別內

我現在有這樣的事情

while($r = mysql_fetch_array($SQL){ 
    $name = $r['name']; 
    $category = $r['category']; 

    echo $category; //I want to be able to echo this once 
    echo $name; // this will be echoed many times depending on the category this falls into 
} 

Answer 1

$category = null; 
while($r = mysql_fetch_array($SQL){ 
    $name = $r['name']; 

    if ($category != $r['category']) { 
     $category = $r['category']; 

     echo $category; //I want to be able to echo this once 
    } 
    echo $name; // this will be echoed many times depending on the category this falls into 
} 

Answer 2

這樣做：

$prev_category = ""; 
while($r = mysql_fetch_array($SQL){ 
    $name = $r['name']; 
    $category = $r['category']; 

    if($prev_category != $category) 
     echo $category; 
    echo $name; 
    $prev_category = $category; 
} 

因此，只有在更改後纔會打印新類別