php - 将mysql结果输出为形式的数组（列名=>列名的可能值）

Question

我有数据库，如

我想创建一个关联数组，以便每个att_name值都与其可能的值相关联att_value：

array('att_name' => array('att_value_1', 'att_value_2', 'att_value_3'))

实现这一目标的最佳方法是什么？

Answer 1

虽然很容易做到这一点，只需选择您想要的结果并在 PHP 中迭代它们以创建您想要的数据结构，您可以将一些工作分给 MySQL GROUP_CONCAT()：

$query = "
  SELECT att_name, GROUP_CONCAT(att_value SEPARATOR ',') AS values
  FROM table_name
  GROUP BY att_name
";
$result = mysql_query($query);

$array = array();
while ($row = mysql_fetch_assoc($result)) {
  $array[$row['att_name']] = explode(',', $values);
}

print_r($array);

当然，这仅在您的值永远不会包含您SEPARATOR在 MySQL 查询中使用的字符（或字符序列）时才有效，因此更安全的纯 PHP 方法是：

$query = "
  SELECT att_name, att_value
  FROM table_name
";
$result = mysql_query($query);

$array = array();
while ($row = mysql_fetch_assoc($result)) {
  $array[$row['att_name']][] = $row['att_value'];
}

print_r($array);

Answer 2

试试下面：

$sql = "SELECT * from tablename";
$result = mysql_query($sql,$con);
$final_array=array();
 while ($row = mysql_fetch_object($result))
   {
      $final_array[$row->att_name][0]=$row->att_value_1;
      $final_array[$row->att_name][1]=$row->att_value_2;
      ....
      ....
   }

Answer 3

This way :

SELECT
    item,
    att_name,
    GROUP_CONCAT(att_value SEPARATOR "<!>") AS att_value
FROM
    table
GROUP BY
    att_name

Will give you something like that :

item    att_name    att_value
-----------------------------
books   height      150 mm<!>250 mm
books   price       rs:20<!>Rs:20
books   size        15 pg<!>30 pg<!>60 pg
books   width       300 mm<!>400 mm

You have to explode the result from att_value by a <!>. I use this <!> so it highly impossible to have a value inside att_value with this. If you think you would someday use this, take another separator. Example : [{--}], _SEPARATOR_, [_-CUT-_], etc. Something you are sure at 100% you won't use a choice but always as a separator to split the text.

So example :

$SQL = 'SELECT item, att_name, GROUP_CONCAT(att_value SEPARATOR "<!>") AS att_value FROM table GROUP BY att_name';
$Query = mysql_query($SQL) or die('MySQL Error : '.mysql_error());

while($Assoc = mysql_fetch_assoc($Query)){
    $Assoc['att_value'] = ($Assoc['att_value'] != '' ? explode('<!>', $Assoc['att_value']) : NULL);
    print_r($Assoc);
}