如何在特定键上合并两个多维数组（唯一键）

Question

My First array is

Array
(
[19] => Array
    (
        [entity_id] => 19
        [entity_type_id] => 4
        [attribute_set_id] => 4
        [type_id] => simple
        [sku] => Escape
        [has_options] => 1
        [required_options] => 0
        [created_at] => 2014-02-27 07:33:53
        [updated_at] => 2014-03-06 07:29:49
        [category_id] => 181
        [pgender] => male
        [name] => Escape 
    )

[32] => Array
    (
        [entity_id] => 32
        [entity_type_id] => 4
        [attribute_set_id] => 4
        [type_id] => simple
        [sku] => Laundry Service
        [has_options] => 1
        [required_options] => 0
        [created_at] => 2014-02-27 19:41:29
        [updated_at] => 2014-03-06 11:02:35
        [category_id] => 181
        [pgender] => both
        [name] => Laundry Service 
    )

)

And Second array is:

Array
(
[20] => Array
    (
        [entity_id] => 20
        [entity_type_id] => 4
        [attribute_set_id] => 4
        [type_id] => simple
        [sku] => Escape
        [has_options] => 1
        [required_options] => 0
        [created_at] => 2014-02-27 07:33:53
        [updated_at] => 2014-03-06 07:29:49
        [category_id] => 181
        [pgender] => male
        [name] => Escape name
    )

[32] => Array
    (
        [entity_id] => 32
        [entity_type_id] => 4
        [attribute_set_id] => 4
        [type_id] => simple
        [sku] => Laundry Service
        [has_options] => 1
        [required_options] => 0
        [created_at] => 2014-02-27 19:41:29
        [updated_at] => 2014-03-06 11:02:35
        [category_id] => 181
        [pgender] => both
        [name] => Laundry Service 
    )

)

I want to merge array by unique key:

Array
(
[1] => Array
    (
        [entity_id] => 19
        [entity_type_id] => 4
        [attribute_set_id] => 4
        [type_id] => simple
        [sku] => Escape
        [has_options] => 1
        [required_options] => 0
        [created_at] => 2014-02-27 07:33:53
        [updated_at] => 2014-03-06 07:29:49
        [category_id] => 181
        [pgender] => male
        [name] => Escape 
    )

[2] => Array
    (
        [entity_id] => 32
        [entity_type_id] => 4
        [attribute_set_id] => 4
        [type_id] => simple
        [sku] => Laundry Service
        [has_options] => 1
        [required_options] => 0
        [created_at] => 2014-02-27 19:41:29
        [updated_at] => 2014-03-06 11:02:35
        [category_id] => 181
        [pgender] => both
        [name] => Laundry Service 
    )
[3] => Array
    (
        [entity_id] => 20
        [entity_type_id] => 4
        [attribute_set_id] => 4
        [type_id] => simple
        [sku] => Escape
        [has_options] => 1
        [required_options] => 0
        [created_at] => 2014-02-27 07:33:53
        [updated_at] => 2014-03-06 07:29:49
        [category_id] => 181
        [pgender] => male
        [name] => Escape name
    )
)

Answer 1

This can be done simply with array_merge - http://bd1.php.net/array_merge

$res = array_merge($arr1, $arr2);

It will preserve the keys from $arr1 that are duplicated in $arr2.