PHP组查询结果为嵌套关联数组

Question

I'm trying to group query results in PHP as an associative array in an efficient manner. I could use multiple nested foreach loops, checking if the current id field matches the previous for each array group, but I'm guessing there are better/more efficient solutions to this problem. Does anyone have a clever solution for this? Ideally a generic function or method that can group any query result set given a key field or array of nested key fields?

Here is the query results array:

Array
(
    [0] => Array
        (
            [look_id] => 3
            [look_name] => Test Look
            [look_description] => description here
            [clothing_article_id] => 1
            [clothing_article_name] => Coat
            [look_clothing_article_attribute_id] => 1
            [look_clothing_article_attribute_name] => Purple
            [clothing_brand_name] => Gap
            [clothing_article_brand_price] => 40.00
            [clothing_article_brand_attribute_price] => 50.00
            [clothing_article_brand_attribute_name] => Purple
        )

    [1] => Array
        (
            [look_id] => 3
            [look_name] => Test Look
            [look_description] => description here
            [clothing_article_id] => 1
            [clothing_article_name] => Coat
            [look_clothing_article_attribute_id] => 2
            [look_clothing_article_attribute_name] => Black
            [clothing_brand_name] => Gap
            [clothing_article_brand_price] => 40.00
            [clothing_article_brand_attribute_price] => 
            [clothing_article_brand_attribute_name] => 
        )

    [2] => Array
        (
            [look_id] => 3
            [look_name] => Test Look
            [look_description] => description here
            [clothing_article_id] => 2
            [clothing_article_name] => Pants
            [look_clothing_article_attribute_id] => 3
            [look_clothing_article_attribute_name] => Cuffed
            [clothing_brand_name] => 
            [clothing_article_brand_price] => 
            [clothing_article_brand_attribute_price] => 
            [clothing_article_brand_attribute_name] => 
        )

)

And this is the array I'd like to convert it to:

Array
(
    'looks' => Array(
        [0] => Array(
            'id' => 3,
            'name' => 'Test Look',
            'description' => 'description here',
            'clothingArticles' => Array(
                [0] => Array(
                    'id' => 1,
                    'name' => 'Coat',
                    'attributes' => Array(
                        [0] => Array(
                            'id' => 1,
                            'name' => 'Purple'
                            'brands' => Array(
                                [0] => Array(
                                    'name' => 'Gap',
                                    'price' => 50.00
                                )
                            )
                        ),
                        [1] => Array(
                            'id' => 2,
                            'name' => 'Black'
                        )
                    ),
                    'brands' => Array(
                        [0] => Array(
                            'name' => 'Gap',
                            'price' => 40.00
                        )
                    )
                ),
                [1] => Array(
                    'id' => 2,
                    'name' => 'Pants',
                    'attributes' => Array(
                        [0] => Array(
                            'id' => 3,
                            'name' => 'Cuffed'
                            'brands' => Array()
                        )
                    ),
                    'brands' => Array()
                )
            )
        )
    )
)

Explanation of grouping relationships:

A look can have 1 or many clothing articles. A clothing article can have 1 or many clothing brands. A look clothing article can have 1 or many attributes. A clothing article brand can have 1 or many attributes.

Answer 1

This shouldn't be too scary to do; rather than using numeric indices for the inner arrays you should use whatever the unique identifier is so you can group on that. This doesn't preclude you from using that identifier in the array itself either.

//seems a little pointless?
$looks = array('looks' => array());
$looks = &$looks['looks'];
while ($row = $result->fetch()) {
    if (!isset($looks[$row->look_id])) {
        $looks[$row->look_id] = array(
            'id' => $row->look_id,
            'name' => $row->look_name,
            'description' => $row->look_description,
            'clothingArticles' => array()
        );
    }
    $look = &$looks[$row->look_id];
    if (!isset($look[$row->clothing_article_id])) {
        //continue this process as needed

Answer 2

Do as many queries as you have join levels, one for each table, all sorted on the same columns and weave the rows together:

$q1 = "SELECT * FROM look ORDER BY look_id";
$q2 = "SELECT look_id, article.* FROM look INNER JOIN article USING(look_id) ORDER BY look_id, article_id";
$q3 = "SELECT look_id, article_id, attribute.* FROM look INNER JOIN article USING(look_id) INNER JOIN attribute USING(article_id) ORDER BY look_id, article_id, attribute_id";

// loop on looks
// inner loop on article and add to look
// inner loop on attribute and add to article

Or you could use a ready made ORM library like doctrine .