无法使用 jq 将 json 解析为 csv

Question

我有一个 JSON 文件，我想使用 shell 脚本中的 jq 将其转换为 CSV 文件。我想从整个 JSON 文件中创建一行。我必须从价值中提取价值。行输出应该类似于

null,642,642,412,0,null,null

Here is my JSON file

{
     "data": [
   {
     "name": "exits",
     "period": "lifetime",
     "values": [
       {
         "value": {}
       }
     ],
     "title": "Exits",
     "description": "Number of times someone exited the carousel"
   },
   {
     "name": "impressions",
     "period": "lifetime",
     "values": [
       {
         "value": 642
       }
     ],
     "title": "Impressions",
     "description": "Total number of times the media object has been seen"
   },
   {
     "name": "reach",
     "period": "lifetime",
     "values": [
       {
         "value": 412
       }
     ],
     "title": "Reach",
     "description": "Total number of unique accounts that have seen the media object"
   },
   {
     "name": "replies",
     "period": "lifetime",
     "values": [
       {
         "value": 0
       }
     ],
     "title": "Replies",
     "description": "Total number of replies to the carousel"
   },
   {
     "name": "taps_forward",
     "period": "lifetime",
     "values": [
       {
         "value": {}
       }
     ],
     "title": "Taps Forward",
     "description": "Total number of taps to see this story's next photo or video"
   },
   {
     "name": "taps_back",
     "period": "lifetime",
     "values": [
       {
         "value": {}
       }
     ],
     "title": "Taps Back",
     "description": "Total number of taps to see this story's previous photo or video"
   }
 ]
}

您好尝试使用这个 jq 命令： .data | map(.values[].value) | @csv

这给出了以下输出： jq：错误（在：70）：对象（{}）在 csv 行中无效 退出状态 5

所以当我得到这个空的 JSON 对象时，它反映了一个错误。

请帮忙！！

行输出应该类似于

null,642,642,412,0,null,null

Answer 1

在这里使用length==0 充其量是可疑的。要检查 {}，可以这样写：

jq '.data | map(.values[].value | if . == {} then "null" else . end) | @csv'

同样适用于 []。

Answer 2

如果你在没有@csv 部分的情况下运行命令，你会看到输出是：

[
  {},
  642,
  412,
  0,
  {},
  {}
]

通过将空对象替换为“null”：(length == 0)

jq '.data | map(.values[].value) | map(if (type == "object" and length == 0 ) then "null" else . end) | @csv'

Output:
"\"null\",642,412,0,\"null\",\"null\""

根据@aaron 的建议（见评论）。以下可以生成请求的输出而无需额外的后处理。免责声明：这不适用于我的 jq 1.5，但适用于 jqplay 和 jq 1.6。

jq --raw-output '.data | map(.values[].value) | map(if (type == "object" and length == 0 ) then "null" else . end) | join(",")'

Output:
null,642,412,0,null,null