JQ解析嵌套数组

Question

我在从 JSON 获取数据时遇到问题：

{
  "operations": [
    {
      "operationName": "GetValue",
      "batch_size": "2",
      "orders": [
        {
          "clientId": "7836",
          "validation_time": {
            "place": "136",
            "execute": "5379"
          }
        },
        {
          "clientId": "7837",
          "validation_time": {
            "place": "145",
            "execute": "5401"
          }
        }
      ]
    },
    {
      "operationName": "GetValue",
      "batch_size": "3",
      "orders": [
        {
          "clientId": "7838",
          "validation_time": {
            "place": "122",
            "execute": "5201"
          }
        },
        {
          "clientId": "7839",
          "validation_time": {
            "place": "122",
            "execute": "5201"
          }
        },
        {
          "clientId": "7840",
          "validation_time": {
            "place": "122",
            "execute": "5201"
          }
        }
      ]
    }
  ]
}

因此，我想获取每个订单的信息，包括 clientId 作为键，place_validation_time 和 execute_validation_time 每个订单。我尝试了以下方法：

.operations[] | select(.operationName=="GetValue") | {key: .orders[].clientId, place_validation_time: .orders[].validation_time.place, execute_validation_time: .orders[].validation_time.execute, batch_size: .batch_size}

但它对我来说有一个意想不到的结果，它将所有 clientId 与validation_time.place 和validation_time.execute 的所有变体结合在一起，所以我得到了4 个（对于batch_size=2）而不是每个订单1 个对象，例如 预期：

{
  "key": "7836",
  "place_validation_time": "136",
  "execute_validation_time": "5379",
  "batch_size": "2"
}

实际我有：

{
  "key": "7836",
  "place_validation_time": "136",
  "execute_validation_time": "5379",
  "batch_size": "2"
}
{
  "key": "7836",
  "place_validation_time": "136",
  "execute_validation_time": "5401",
  "batch_size": "2"
}
{
  "key": "7836",
  "place_validation_time": "145",
  "execute_validation_time": "5379",
  "batch_size": "2"
}
{
  "key": "7836",
  "place_validation_time": "145",
  "execute_validation_time": "5401",
  "batch_size": "2"
}

有人知道如何避免它并因此每 1 个订单获得 1 个对象吗？

Answer 1

笛卡尔积行为是在对象构造表达式内的多个位置包含.orders[] 的结果。而是将其吊起。假设你想选择.batch_size等于“2”的对象，你可以这样写：

.operations[]
| select(.operationName=="GetValue")
| .batch_size as $batch_size
| select($batch_size == "2")
| .orders[]
| {key: .clientId,
   place_validation_time: .validation_time.place,
   execute_validation_time: .validation_time.execute,
   batch_size: $batch_size}

附录

如果您在 .batch_size 级别有其他感兴趣的项目，您可能希望使用更像这样的过滤器：

.operations[]
| select(.operationName=="GetValue")
| . as $it
| select($it.batch_size == "2")
| .orders[]
| {key: .clientId,
   place_validation_time: .validation_time.place,
   execute_validation_time: .validation_time.execute,
   batch_size: $it.batch_size}