How can I (generically) transform the input file below to the output file below, using jq. The record format of the output file is: array_index | key | value
Input file:
[{"a": 1, "b": 10},
{"a": 2, "d": "fred", "e": 30}]
Output File:
0|a|1
0|b|10
1|a|2
1|d|fred
1|e|30
Here's a solution using tostream, which creates a stream of paths and their values. Filter out those having values using select, flatten to align both, and join for the output format:
jq -r 'tostream | select(has(1)) | flatten | join("|")'
0|a|1
0|b|10
1|a|2
1|d|fred
1|e|30
Or a very similar one using paths to get the paths, scalars for the filter, and getpath for the corresponding value:
jq -r 'paths(scalars) as $p | [$p[], getpath($p)] | join("|")'
0|a|1
0|b|10
1|a|2
1|d|fred
1|e|30
< file.json jq -r 'to_entries
| .[]
| .key as $k
| ((.value | to_entries )[]
| [$k, .key, .value])
| @csv'
Output:
0,"a",1
0,"b",10
1,"a",2
1,"d","fred"
1,"e",30
You just need to remove the double quotes.
to_entries can be used to loop over the elements of arrays and objects in a way that gives both the key (index) and the value of the element.
jq -r '
to_entries[] |
.key as $id |
.value |
to_entries[] |
[ $id, .key, .value ] |
join("|")
'
Demo on jqplay
Replace join("|") with @csv to get proper CSV.
