如何用jq将json文档中的空值替换为特定值？

Question

我有一个包含的json文件 nulls as values for some keys, which I would like to replace with some specific value.

鉴于此输入：

{
  "id": null,
  "rows": [
    {
      "panels": [
        {
          "title": "Panel1",
          "datasource": null
        },
        {
          "title": "Panel2",
          "datasource": null
        }
      ]
    }
  ]
}

我想拥有

{
  "id": null,
  "rows": [
    {
      "panels": [
        {
          "title": "Panel1",
          "datasource": "mydb"
        },
        {
          "title": "Panel2",
          "datasource": "mydb"
        }
        ]
     }
  ]
}

What I currently use is

sed 's/"datasource": null/"datasource": "mydb"/'

This produces the output I need, but I keep thinking that it is a shame to use sed for this job, when there are tools like jq that can work on JSON in a much better way.

Answer 1

首先，您需要确定要更新的对象。由于您要将面板的空数据源设置为"mydb"，因此可以执行以下操作：

$ jq '.rows[].panels[].datasource //= "mydb"' input.json

如果要datasource在任何级别更新任何对象上的任何属性，可以使用..递归搜索它们。

$ jq '(.. | select(objects | has("datasource"))).datasource //= "mydb"' input.json