Laravel验证：禁止订单中重复选择同一商品

问题场景 #

需要实现订单多商品的重复验证，确保单个订单中不能选择同一商品。从请求数据可以看到，product_id0和product_id1的值均为1，属于重复商品，但现有验证逻辑无法正确检测，甚至在商品ID不同时仍返回错误提示。

请求数据示例：

+request: Symfony\Component\HttpFoundation\InputBag {#45
#parameters: array:16 [
  "_token" => "El3iq45CsoEPRXxwaAOv072O0bWARb5WUNx3Lmfe"
  "warehouse_id" => "1"
  "customer_id" => "1"
  "order_date" => "2023-08-24 19:20"
  "shipping_address" => "q"
  "product_id0" => "1"
  "qty0" => "1"
  "stock_outstanding0" => "99"
  "unit_price0" => "65000"
  "total_price0" => "65000"
  "count_item" => "1"
  "product_id1" => "1"
  "qty1" => "1"
  "stock_outstanding1" => "100"
  "unit_price1" => "65000"
  "total_price1" => "65000"
]
}

错误的验证逻辑 #

第一种错误实现 #

$isValid = true;

for ($g = 0; $g <= $request->count_item; $g++) {
    $validator = Validator::make($request->all(), [
        'warehouse_id' => 'required',
        'customer_id' => 'required',
        'order_date' => 'required',
        'shipping_address' => 'required',
        "product_id{$g}.*" => 'distinct',
    ]);

    if ($validator->fails()) {
        $isValid = false;
        break;
    }
}

if ($isValid) {
    return response()->json([
        'status' => true,
        'message' => 'Validation Work',
    ]);
} else {
    return response()->json([
        'status' => false,
        'message' => 'Validation Failed',
    ]);
}

第二种错误实现 #

$tempId = [];
$tempArray = [];

for ($g=0; $g <= $request->count_item; $g++) { 
    $tempId[] = $request['product_id' . $g];

    if(in_array($tempId, $tempArray)){
        return response()->json([
            'status' => true,
            'message' => 'True validation work',
        ]);
    }else{
        return response()->json([
            'status' => false,
            'message' => 'False validation failed',
        ]);
        $tempArray[] = $tempId;
        dd($tempArray);
        exit;
    }
}

正确的解决方案 #

方案1：使用Laravel验证器distinct规则（推荐） #

先收集所有商品ID为数组，再针对数组验证唯一性：

// 收集所有商品ID
$productIds = [];
for ($g = 0; $g <= $request->count_item; $g++) {
    $productIds[] = $request->input("product_id{$g}");
}

// 构建验证规则
$validator = Validator::make(
    array_merge($request->all(), ['product_ids' => $productIds]),
    [
        'warehouse_id' => 'required',
        'customer_id' => 'required',
        'order_date' => 'required',
        'shipping_address' => 'required',
        'product_ids' => 'array|distinct',
    ]
);

if ($validator->fails()) {
    return response()->json([
        'status' => false,
        'message' => '订单中存在重复商品，请检查后重新提交',
        'errors' => $validator->errors()
    ]);
}

return response()->json([
    'status' => true,
    'message' => '验证通过'
]);

方案2：手动遍历检测重复 #

$productIds = [];
$hasDuplicate = false;

// 检测重复商品ID
for ($g = 0; $g <= $request->count_item; $g++) {
    $currentId = $request->input("product_id{$g}");
    if (in_array($currentId, $productIds)) {
        $hasDuplicate = true;
        break;
    }
    $productIds[] = $currentId;
}

// 验证必填字段
$requiredValidator = Validator::make($request->all(), [
    'warehouse_id' => 'required',
    'customer_id' => 'required',
    'order_date' => 'required',
    'shipping_address' => 'required',
]);

if ($requiredValidator->fails()) {
    return response()->json([
        'status' => false,
        'message' => '必填字段不能为空',
        'errors' => $requiredValidator->errors()
    ]);
}

if ($hasDuplicate) {
    return response()->json([
        'status' => false,
        'message' => '订单中存在重复商品，请检查后重新提交'
    ]);
}

return response()->json([
    'status' => true,
    'message' => '验证通过'
]);

错误原因分析 #

1. 第一种错误逻辑：循环中单次验证单个product_id{g}的distinct规则，但distinct是针对数组的校验规则，单个字段使用该规则不会生效，导致无论是否重复都判定验证通过。
2. 第二种错误逻辑：循环第一次就直接返回结果，未遍历全部商品ID；且in_array($tempId, $tempArray)是将数组作为元素查找，逻辑错误，应直接比较单个商品ID是否已存在。

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