使用group by或join

Question

我有这两张桌子：

   categories
    +----+----------------+
    | ID | name           |
    +----+----------------+
    |  1 | First category |
    |  2 | Second category|
    |  3 | Third category |
    +----+----------------+
    subcategories
    +----+----------+----------------+
    | ID | category | name           |
    +----+----------+----------------+
    |  1 |        1 | 1.1 subcategory|
    |  2 |        1 | 1.2 subcategory|
    |  3 |        1 | 1.3 subcategory|
    |  4 |        2 | 2.1 subcategory|
    |  5 |        2 | 2.2 subcategory|
    |  6 |        2 | 2.3 subcategory|
    |  7 |        3 | 3.1 subcategory|
    |  8 |        3 | 3.1 subcategory|
    |  9 |        3 | 3.3 subcategory|
    +----+----------+----------------+

我需要一个查询，它会得到如下结果：

Array( [0] => Array ( [category] = First category, [subcategory] => Array( [0] => "1.1 subcategory", [1] => "1.2 subcategory", [2] => "1.3 subcategory")), [1] => Array ( [category] = Second category, [subcategory] => Array( [0] => "2.1 subcategory", [1] => "2.2 subcategory", [2] => "2.3 subcategory")), [2] => Array ( [category] = Third category, [subcategory] => Array( [0] => "3.1 subcategory", [1] => "3.2 subcategory", [2] => "3.3 subcategory")))

我认为这与group by + join

有关

我试过的查询

SELECT 
    categories.name, 
    subcategories.name
FROM categories     
INNER JOIN
    subcategories ON
    categories.id = subcategories.category  
GROUP BY categories.name

Answer 1

我认为你应该使用2个SQL语句并重新构建数组。