动态命名变量？

Question

我有一个表与各种拍卖，其中每个记录都有用户名和类别。很可能，会有多个具有相同用户名和类别的记录。有四种不同的类别。

我想知道是否有可能，在下面的准备查询，让第二个绑定参数是循环包含4个类别的数组的结果，如果我可以动态地将结果分配给数组？

$countAuctionsQuery = "select COUNT(USERNAME, SUBCAT) from AUCTIONS where username = ? AND SUBCAT = ?"; 

    if ($getRecords = $con->prepare($countAuctionsQuery)) 
     { 
     $getRecords->bind_param("ss", $username, $subcat); 
     $getRecords->execute();   
     $getRecords->bind_result($numRecords); 
     } 

编辑：

数据

Auctions 


username itemnumber cost category 
------------------------------------------------ 
fredx  222  $33 fake 
fredx  123  $43 fake 
timo  765  $54 fake 
fredx  987  $99 sold 
bobk  233  $77 fake 
wenx  11  $12 ok 
fredx  23  $31 ok 
fredx  723  $73 fake 
wenx  44  $88 ok 

所以，对用户名和fredx类假，3应退还的一个例子。

对于用户名fredx和类别出售，1应返回

对于用户名和蒂莫类假，1应返回

对于用户名和wenx类别确定; 2应返回。

我希望能够打印出像这样：在一个循环中

SELECT subcat, COUNT(*) 
FROM AUCTIONS 
WHERE username = ? 
GROUP BY 
     subcat 

，并获取结果：

$countAuctionsQuery = $query; 

if ($getRecords = $con->prepare($countAuctionsQuery)) { 
    $getRecords->bind_param("s", $username); 
    $getRecords->execute();   
    $getRecords->bind_result($subcat, $numRecords); 
    while ($getRecords->fetch()) { 
     print "$subcat items: $numRecords items of category['$subcat']"; 
    } 
} 

Answer 1

试试这个

Fake items: $numfake items or category['fake'] 
OK items: $numok items or category['ok'] 
Sold items: $numsold items or category['sold'] 

Answer 2

使用此：

function getCategoryCount($user, $conn) { 
    $result = array(); 
    $query = "SELECT category, COUNT(id) AS count FROM Auctions 
       WHERE username=? GROUP BY category"; 
    $stmt = $conn->prepare($query); 
    $stmt->bind_param('s',$user); 
    $stmt->execute(); 
    $stmt->bind_result($cat, $count); 
    while ($stmt->fetch()) { 
     $result[$cat] = $count; 
    } 
    return $result; 
} 

您可以使用这样的功能：

$count = getCategoryCount('fred', $con); 
print $count['fake']; // prints '3' 

反过来，你也可以这样做：

$query = "SELECT category, COUNT(id) AS count FROM Auctions 
      WHERE username=? GROUP BY category"; 
$stmt = $con->prepare($query); 
$stmt->bind_param('s',$user); 
$user = 'fred'; 
$stmt->execute(); 
$stmt->bind_result($cat, $count); 
while ($stmt->fetch()) { 
    ${'num'.$cat} = $count; 
} 

print $numfake; 
print $numok; 
print $numsold;