Jolt Shift转换数组输出出现Null，求修正方案

Hey there! I see the annoying null value popping up in your second object's LOCATIONS array—let's get this sorted out right away.

The Root Cause #

The issue comes from how you're indexing the LOCATIONS array in your shift spec. Right now you're using [&1] for the LOCATIONS index:

"BUILDING": "[&1].LOCATIONS.[&1].Building",

That inner &1 refers to the index of the parent COMPINFO array element. For the first COMPINFO entry (index 0), this maps to LOCATIONS[0] which works perfectly. But for the second entry (index 1), it tries to map to LOCATIONS[1]—leaving the LOCATIONS[0] slot empty, which gets filled with null.

The Simple Fix #

Since each COMPINFO entry should only have one location object in its LOCATIONS array, replace the inner [&1] with a fixed [0] index. Here's the corrected spec:

[
  {
    "operation": "shift",
    "spec": {
      "data": {
        "COMPINFO": {
          "*": {
            "COMPID": "[&1].COMPID",
            "ORGID": "[&1].ORGID",
            "COMP_DESC": "[&1].DESCRIPTION",
            "BUILDING": "[&1].LOCATIONS.[0].Building",
            "FLR_LEVEL": "[&1].LOCATIONS.[0].Floor_Level",
            "ROOM_SPCE": "[&1].LOCATIONS.[0].ROOM_SPCE",
            "SITEID": "[&1].SITEID",
            "ASSETTYPE": "[&1].ASSETTYPE"
          }
        }
      }
    }
  }
]

Verified Output #

With this adjusted spec, your output will match exactly what you expected:

[
  {
    "COMPID": "C2014",
    "ORGID": "",
    "DESCRIPTION": "Cherokee High School",
    "LOCATIONS": [
      {
        "Building": "Main",
        "Floor_Level": "Ground",
        "ROOM_SPCE": "100"
      }
    ],
    "SITEID": "BWDEMO",
    "ASSETTYPE": "MANUFACTURING"
  },
  {
    "COMPID": "9001B",
    "ORGID": "",
    "DESCRIPTION": "Sludge Pump",
    "LOCATIONS": [
      {
        "Building": "Main",
        "Floor_Level": "Production",
        "ROOM_SPCE": "100"
      }
    ],
    "SITEID": "BWDEMO",
    "ASSETTYPE": "FACILITY"
  }
]

No more unwanted nulls—each LOCATIONS array now holds exactly one location object as intended!

内容的提问来源于stack exchange，提问作者Pratik Jaiswal