echo '[{"name":"john", "grades":[1,2,3]}, {"name":"jane", "grades":[4,5,6]}]'| jq '.[]| "\(.name), \(.grades|.[])"'
echo '[{"name":"john", "grades":[1,2,3]}, {"name":"jane", "grades":[4,5,6]}]' | jq -r '.[] | "\(.name),\(.grades|.[])"' | paste -sd' ' -