php 组合两个数组的子数组，其中某个键的值相等

Question

您好，感谢您的关注

我有两个数组:

[A] - 来自 server1 上一个数据库的 mysql 查询 - $postings_array - 讨论线程的所有帖子的 SELECT （基于线程的 id）
[B] - 来自 server2 上其他数据库的 mysql 查询 - $usersdata_array - 讨论线程的所有帖子的 SELECT （基于线程的 id）

这意味着：

在[A]中有很多postings-sub-arrays和在[B]中有一个或多个用户数据子数组。
两个数组总是在它们的每个数组中包含一个名为 usrsID 的键子数组。

I need to extend the Sub-Arrays in $postings_array [A]

by merging them 

with the Sub-Arrays of the $usersdata_array [B]

based on WHERE the VALUE of the usrsID KEY in the sub-array[A] is EQUAL to the usrsID KEY in the sub-array[B].

示例：

Array [A]:
(
    [0] => Array
        (
            [ID] => 5
            [usrsID] => 3
            [tid] => 19
            [txtid] => 22
        )
    [1] => Array
        (
            [ID] => 6
            [usrsID] => 1
            [tid] => 19
            [txtid] => 23
        )
    [2] => Array
        (
            [ID] => 7
            [usrsID] => 2
            [tid] => 19
            [txtid] => 24
        )
    [3] => Array
        (
            [ID] => 8
            [usrsID] => 1
            [tid] => 19
            [txtid] => 25
        )
)

--

Array [B]:
(
    [0] => Array
        (
            [id] => 1
            [usrsID] => 1
            [avatarID] => 1

        )
    [1] => Array
        (
            [id] => 2
            [usrsID] => 2
            [avatarID] => 3

        )
    [2] => Array
        (
            [id] => 3
            [usrsID] => 3
            [avatarID] => 22

        )

)

需要的结果（上面例子中的 [B] 扩展 [A]）：

Array [A_extended]:
(
    [0] => Array
        (
            [ID] => 5
            [usrsID] => 3
            [tid] => 19
            [txtid] => 22
            [id] => 3
            [avatarID] => 22
        )
    [1] => Array
        (
            [ID] => 6
            [usrsID] => 1
            [tid] => 19
            [txtid] => 23
            [id] => 1
            [avatarID] => 1
        )
    [2] => Array
        (
            [ID] => 7
            [usrsID] => 2
            [tid] => 19
            [txtid] => 24
            [id] => 2
            [avatarID] => 3
        )
    [3] => Array
        (
            [ID] => 8
            [usrsID] => 1
            [tid] => 19
            [txtid] => 25
            [id] => 1
            [avatarID] => 1
        )
)

...我认为，这是一个常见问题，因此应该有一个最佳实践（可能在一个内置 php 函数中或两个或三个函数的组合中）——我确实这样做不必重新发明轮子。至少，我希望如此...

否则，我的做法是

check the amounts of iterations (= the subarrays found in the $usersdata_array [B] )

iterate over the outerHaystack and trigger a function when $needle was found in innerHaystack

perform merge via checkSubArrayfunc

方法， with hayStackArray = complete [A]Array; needle = [B] 子数组的 $usrsID 值：

function checkSubArrayfunc($hayStackSubArray, $needle, $toMergeSubArray) {

        if (in_array(array('$hayStackSubArray'), $needle)) {
                array_merge_recursive($hayStackSubArray, $toMergeSubArray);
        }
    }

Answer 1

首先取一个空数组作为store marged array。然后在两个数组中遍历。如果 userID 在两个元素数组中都相同，则合并这些数组并推入 margeArr.

$margeArr = [];
foreach($Array_A as $a){
  foreach($Array_B as $b){
    if($a['usrsID'] == $b['usrsID']){
      array_push($margeArr,array_merge($a,$b));
    }
  }
}
print_r($margeArr);

Comment by the questionaire: It's a great solution - it really meets the requirements described in my question and merges the to be marged Array with the key-value-pairs of the "to be injected"-Array. But I prefere the bestprogrammersinintheworld's solution, where I can rename the keys "en passant / on-the-fly":

foreach($arr_b as $b_item) {
    foreach($arr_a as $key => &$a_item) {
        if ($b_item['usrsID'] == $a_item['usrsID']) {
            $a_item['myNewKeyName1'] = $b_item['usrsID'];
            $a_item['myNewKeyName2'] = $b_item['avatarID'];
        }
    }
}
print("<pre>".print_r($arr_a,true)."</pre>");

Answer 2

试试这个：

foreach($arr_b as $b_item) {
    foreach($arr_a as $key => &$a_item) {
        if ($b_item['usrsID'] == $a_item['usrsID']) {
            $a_item['id'] = $b_item['usrsID'];
            $a_item['avatarID'] = $b_item['avatarID'];
        }
    }
}

您 $_arr_a 的输出将是：

Array
(
    [0] => Array
        (
            [ID] => 5
            [usrsID] => 3
            [tid] => 19
            [txtid] => 22
            [id] => 3
            [avatarID] => 22
        )

    [1] => Array
        (
            [ID] => 6
            [usrsID] => 1
            [tid] => 19
            [txtid] => 23
            [id] => 1
            [avatarID] => 1
        )

    [2] => Array
        (
            [ID] => 7
            [usrsID] => 2
            [tid] => 19
            [txtid] => 24
            [id] => 2
            [avatarID] => 3
        )

    [3] => Array
        (
            [ID] => 8
            [usrsID] => 1
            [tid] => 19
            [txtid] => 25
            [id] => 1
            [avatarID] => 1
        )

)

php 组合两个数组的子数组，其中某个键的值相等

php combine two array's subarrays where value of certain key is equal

php

arrays

array-merge

示例：