jq：从嵌套对象中选择子集键

Question

输入：

{"success": true, "results": {"a": …, "b": …, "c": …}}

假设我想保留b，期望的输出如下：

{"success": true, "results": {"b": …}}

我尝试过的方法：

$ jq 'del(select(.results.b | not))'
{"success": true, "results": {"a": …, "b": …, "c": …}}
# removes nothing from "results"

$ jq 'with_entries(select(.key == "success" or .key == "results.b"))'
{"success": true}
# nested comparison not understood; returns only "success"

谢谢！

- zopieux

Answer 1

以下是一个解决方案：

.results |= {b}

样例运行

$ jq -M '.results |= {b}' <<< '{"success":true, "results":{"a": "…", "b": "…", "c": "…"}}'
{
  "success": true,
  "results": {
    "b": "…"
  }
}

Try it online at jqplay.org

- jq170727

---

{btsdaf} - zopieux

Answer 2

另一种使用 nodejs 和 shell 的方法：

代码：

$ node<<EOF
var obj = $(</tmp/file.json);
delete obj.results.a;
delete obj.results.c;
console.log(JSON.stringify(obj));
EOF

输出：

{"success":true,"results":{"b":"bbb"}}

- Gilles Quénot