PHP中按ID匹配从次要数组向主数组添加属性

主数组 $allcustomers 结构 #

array:4 [▼
  0 => array:13 [▼
    "id" => 4
    "name" => "shahd"
    "gender" => "F"
    "helper_code" => null
    "age" => 255.0
    "dob" => 1768.0
    "mobile_no" => "01789654123"
    "category" => null
    "status" => 0
    "created_by" => 8
    "updated_by" => null
    "created_at" => "2023-08-14T18:56:26.000000Z"
    "updated_at" => null
  ]
  1 => array:13 [▼
    "id" => 2
    "name" => "amr"
    "gender" => "M"
    "helper_code" => 252
    "age" => 25.0
    "dob" => 1998.0
    "mobile_no" => "01252523987"
    "category" => "Mixed"
    "status" => 47
    "created_by" => 8
    "updated_by" => 8
    "created_at" => "2023-08-10T08:05:00.000000Z"
    "updated_at" => "2023-08-10T19:35:00.000000Z"
  ]
  2 => array:13 [▼
    "id" => 1
    "name" => "mohamed shaker"
    "gender" => "M"
    "helper_code" => 2525
    "age" => 2.0
    "dob" => 2021.0
    "mobile_no" => "01999999999"
    "category" => "Mixed"
    "status" => 9
    "created_by" => 8
    "updated_by" => 8
    "created_at" => "2023-08-01T09:51:51.000000Z"
    "updated_at" => "2023-08-10T10:57:43.000000Z"
  ]
  3 => array:13 [▼
    "id" => 3
    "name" => "tasnim"
    "gender" => "F"
    "helper_code" => 255
    "age" => 25.0
    "dob" => 1998.0
    "mobile_no" => "01252525256"
    "category" => null
    "status" => 0
    "created_by" => 8
    "updated_by" => null
    "created_at" => "2023-07-11T19:13:55.000000Z"
    "updated_at" => null
  ]
]

次要数组 $lastvisitdate 结构 #

array:2 [▼
  0 => array:2 [▼
    "id" => 1
    "date" => "2023-08-28"
  ]
  1 => array:2 [▼
    "id" => 2
    "date" => "2023-08-10"
  ]
]

需求说明 #

根据ID匹配，将次要数组中的date字段添加到主数组中。若主数组中的ID在次要数组中不存在，则对应的date字段设为null。

期望结果 #

array:4 [▼
  0 => array:13 [▼
    "id" => 4
    "name" => "shahd"
    "gender" => "F"
    "helper_code" => null
    "age" => 255.0
    "dob" => 1768.0
    "mobile_no" => "01789654123"
    "category" => null
    "status" => 0
    "created_by" => 8
    "updated_by" => null
    "created_at" => "2023-08-14T18:56:26.000000Z"
    "updated_at" => null
    "date" => null
  ]
  1 => array:13 [▼
    "id" => 2
    "name" => "amr"
    "gender" => "M"
    "helper_code" => 252
    "age" => 25.0
    "dob" => 1998.0
    "mobile_no" => "01252523987"
    "category" => "Mixed"
    "status" => 47
    "created_by" => 8
    "updated_by" => 8
    "created_at" => "2023-08-10T08:05:00.000000Z"
    "updated_at" => "2023-08-10T19:35:00.000000Z"
     "date" => "2023-08-10"
  ]
  2 => array:13 [▼
    "id" => 1
    "name" => "mohamed shaker"
    "gender" => "M"
    "helper_code" => 2525
    "age" => 2.0
    "dob" => 2021.0
    "mobile_no" => "01999999999"
    "category" => "Mixed"
    "status" => 9
    "created_by" => 8
    "updated_by" => 8
    "created_at" => "2023-08-01T09:51:51.000000Z"
    "updated_at" => "2023-08-10T10:57:43.000000Z"
    "date" => "2023-08-28"
  ]
  3 => array:13 [▼
    "id" => 3
    "name" => "tasnim"
    "gender" => "F"
    "helper_code" => 255
    "age" => 25.0
    "dob" => 1998.0
    "mobile_no" => "01252525256"
    "category" => null
    "status" => 0
    "created_by" => 8
    "updated_by" => null
    "created_at" => "2023-07-11T19:13:55.000000Z"
    "updated_at" => null
    "date" => null
  ]
]

解决方案 #

实现步骤 #

1. 将次要数组转换为以id为键、date为值的关联数组，实现O(1)时间复杂度的快速查找。
2. 遍历主数组，为每个元素添加date字段，值为关联数组中对应id的值（存在则取，否则设为null）。

示例代码（PHP） #

// 将次要数组转换为id => date的关联数组
$dateMap = array_column($lastvisitdate, 'date', 'id');

// 遍历主数组添加date字段
foreach ($allcustomers as &$customer) {
    $customer['date'] = $dateMap[$customer['id']] ?? null;
}
unset($customer); // 解除引用，避免后续操作影响原数组

// 输出结果
print_r($allcustomers);

代码说明 #

• array_column($lastvisitdate, 'date', 'id')：高效转换数组结构，把id作为键，date作为对应值，大幅提升查找效率。
• $dateMap[$customer['id']] ?? null：使用PHP的null合并运算符，简洁处理存在/不存在的情况，避免报错。
• 遍历主数组时使用引用&$customer，直接修改原数组元素，无需额外创建新数组。

内容的提问来源于stack exchange，提问作者Mohamed shaker