Very close! In your select
expression, you have to use a pipe (|
) before contains
.
This filter produces the expected output.
. - map(select(.Names[] | contains ("data"))) | .[] .Id
The jq Cookbook has an example of the syntax.
Filter objects based on the contents of a key
E.g., I only want objects whose genre key contains "house".
$ json='[{"genre":"deep house"}, {"genre": "progressive house"}, {"genre": "dubstep"}]' $ echo "$json" | jq -c '.[] | select(.genre | contains("house"))' {"genre":"deep house"} {"genre":"progressive house"}
Colin D asks how to preserve the JSON structure of the array, so that the final output is a single JSON array rather than a stream of JSON objects.
The simplest way is to wrap the whole expression in an array constructor:
$ echo "$json" | jq -c '[ .[] | select( .genre | contains("house")) ]'
[{"genre":"deep house"},{"genre":"progressive house"}]
You can also use the map function:
$ echo "$json" | jq -c 'map(select(.genre | contains("house")))'
[{"genre":"deep house"},{"genre":"progressive house"}]
map unpacks the input array, applies the filter to every element, and creates a new array. In other words, map(f)
is equivalent to [.[]|f]
.