使用jq从内部数组按条件取值并移至数组外部的实现方法

Got it, let's break down how to use jq to pull specific tag values from the nested tags array inside each assets element and attach them as top-level fields to the asset itself. I'll cover a couple common scenarios based on your sample JSON.

Sample Input JSON #

First, let's restate your input for reference:

{
  "data": {
    "assets": [
      {
        "aDASD": "1056bda9-2598-4fdf-bd99-db3924464a75",
        "KEY": "a7e2ef79-41aa-4a36-9ca1-1f388917eb12.ahnl",
        "key2": "store-order-picking-units-api",
        "key3": "1.0.1",
        "tags": [
          { "value": "abcd", "key": null, "mutable": false },
          { "value": "rest", "key": null, "mutable": false },
          { "value": "123", "key": null, "mutable": false },
          { "value": "system", "key": null, "mutable": true },
          { "value": "market", "key": null, "mutable": true }
        ],
        "type": "mytype"
      }
    ]
  }
}

Scenario 1: Extract all tags where mutable: true into a new array field #

If you want to collect all tag values that have mutable: true and add them as a mutable_tag_values field to each asset, use this jq command:

.data.assets[] |= (
  . + {
    mutable_tag_values: [.tags[] | select(.mutable == true) | .value]
  }
) | { data: { assets: [.data.assets[]] } }

Explanation: #

• .data.assets[] |=: Iterate over each asset element and modify it in-place
• . + { ... }: Merge the original asset with a new field we're creating
• mutable_tag_values: [.tags[] | select(.mutable == true) | .value]: Filter tags to only those where mutable is true, extract their value, and wrap the results in an array
• | { data: { assets: [.data.assets[]] } }: Reconstruct the original JSON structure after modifications

Output for this scenario: #

{
  "data": {
    "assets": [
      {
        "aDASD": "1056bda9-2598-4fdf-bd99-db3924464a75",
        "KEY": "a7e2ef79-41aa-4a36-9ca1-1f388917eb12.ahnl",
        "key2": "store-order-picking-units-api",
        "key3": "1.0.1",
        "tags": [/* original tags array */],
        "type": "mytype",
        "mutable_tag_values": ["system", "market"]
      }
    ]
  }
}

Scenario 2: Extract a specific tag value (e.g., where value == "system") as a single field #

If you only need a specific tag value (like "system") as a top-level field, use this:

.data.assets[] |= (
  . + {
    system_tag: .tags[] | select(.value == "system") | .value
  }
) | { data: { assets: [.data.assets[]] } }

Output for this scenario: #

{
  "data": {
    "assets": [
      {
        "aDASD": "1056bda9-2598-4fdf-bd99-db3924464a75",
        "KEY": "a7e2ef79-41aa-4a36-9ca1-1f388917eb12.ahnl",
        "key2": "store-order-picking-units-api",
        "key3": "1.0.1",
        "tags": [/* original tags array */],
        "type": "mytype",
        "system_tag": "system"
      }
    ]
  }
}

Scenario 3: Extract multiple specific tags into individual fields #

If you want to pull multiple specific tags into their own fields (e.g., "rest" and "market"), you can extend the approach:

.data.assets[] |= (
  . + {
    rest_tag: (.tags[] | select(.value == "rest") | .value),
    market_tag: (.tags[] | select(.value == "market") | .value)
  }
) | { data: { assets: [.data.assets[]] } }

Pro Tip: #

If you want to remove the original tags array after extracting the values, just add del(.tags) inside the modification block:

.data.assets[] |= (
  . + { mutable_tag_values: [.tags[] | select(.mutable == true) | .value] }
  | del(.tags)
) | { data: { assets: [.data.assets[]] } }

内容的提问来源于stack exchange，提问作者Naveen K Reddy