Parse or view JSON data fields using JQ tool utility where field names have a “-” dash in the key name

Question

I have a JSON data file (as shown below) and I\'m trying to find field values using jq utility.

It\'s working fine except for fields if the key name contains a

Answer 1

I don't know about jq, but you put python in the tags so:

$ cat test.json | python -c "import sys, json; print(json.load(sys.stdin)['content']['book1']['field-three']['name'])"
THIRD

or without the pipe:

$ python -c "import json; print(json.load(open('test.json'))['content']['book1']['field-three']['name'])"

Answer 2

"-" is used for negation in jq. For key names with special characters such as "-", one cannot use the simplified ".keyname" syntax. There are several alternatives, but the most robust is simply to use the form .["KEY NAME"], which can be abbreviated to ["KEY NAME"] when chained, e.g. .a["b-c"] is shorthand for .a | .["b-c"].

If in doubt, use the pipe explicitly.

For further information, please consult the jq manual and/or https://github.com/stedolan/jq/wiki/FAQ

Answer 3

As explained in the jq manual, to handle keys with non-identifier characters like - you can use double quotes.

From the shell this is easiest if you use single quotes around your filter. For example, try the following commands:

cat /tmp/my.data.json | jq '.pages'
cat /tmp/my.data.json | jq '.pages.book1[0]'
cat /tmp/my.data.json | jq '.pages.book1[1]'
cat /tmp/my.data.json | jq '.content'
cat /tmp/my.data.json | jq '.content.book1'
cat /tmp/my.data.json | jq '.content.book1.name'
cat /tmp/my.data.json | jq '.content.book1.field1'
cat /tmp/my.data.json | jq '.content.book1."field-2"'
cat /tmp/my.data.json | jq '.content.book1."field-three"'
cat /tmp/my.data.json | jq '.content.book1."field-three".url'
cat /tmp/my.data.json | jq '.content.book1.authur'
cat /tmp/my.data.json | jq '.content.book1.route'

Answer 4

Hm..took some time but finally it seems like we need to DOUBLE QUOTE it and back slash just the double quote for any key name containing a - in it's name.

$ cat /tmp/my.data.json| jq ".content.book1.\"field-2\""                    
"value-2"

$ cat /tmp/my.data.json| jq ".content.book1.\"field-three\".\"url\""  
"book1/field-three/"

OR if you wrap everything in a single quotes ', then we do NOT need to backslash " double quotes but use double quotes for key names with - in their name.

$ cat /tmp/my.data.json| jq '.content.book1."field-three"."url"'  
"book1/field-three/"

Hope it helps! Took some help/hint from https://jqplay.org/

See this for more: https://github.com/stedolan/jq/issues/38#issuecomment-9770240