如何使用jq将来自不同JSON对象的值合并到一行CSV

Question

I want to extract data from a JSON file and write it to a CSV file using jq .

This is a sample of my data:

[
  {
    "media": {
      "track": [
        {
          "attype": "General",
          "FileExtension": "MP4",
          "Format": "MPEG-4"
        },
        {
          "attype": "Video",
          "Format": "MPEG Video"
        }
      ]
    }
  },
  {
    "media": {
      "track": [
        {
          "attype": "General",
          "FileExtension": "ts",
          "Format": "MPEG-TS"
        },
        {
          "attype": "Video",
          "Format": "MPEG Video"
        }
      ]
    }
  }
]

This is the desired output:

"MP4","MPEG-4","MPEG Video"
"ts","MPEG-TS","MPEG Video"

This is my jq code:

.[].media.track[] |
  [
    (select(.attype =="General") | .FileExtension, .Format),
    (select(.attype =="Video") | .Format)
  ] | @csv

This is the actual output:

"MP4","MPEG-4"
"MPEG Video"
"ts","MPEG-TS"
"MPEG Video"

I have experimented with the flatten filter and with different usage of the square brackets [] for array construction, but to no avail. How can I reach the desired output with jq ?

Answer 1

You're on the right track (pun intended) -- you just have to expand .track as follows:

.[].media.track
| [.[]
   | (select(.attype =="General") | .FileExtension, .Format),
     (select(.attype =="Video") | .Format) ]
| @csv

Alternatively ...

If you find all those brackets and parentheses to be too distracting, you could go with:

.[].media.track
| map( if .attype =="General" then .FileExtension, .Format
       elif .attype =="Video" then .Format
       else empty
       end )
| @csv

Answer 2

A solution is to create a cells array for each media rather than for each track :

.[].media | 
  [ 
    .track[] |
       (select(.attype =="General") | .FileExtension, .Format),
       (select(.attype =="Video") | .Format)
  ] | @csv