如何将包含在一条消息中的 JSON 对象数组转换为多个 JSON 对象消息？

Question

目前正在 Node-RED 中创建一个 ETL 流运行，运行在 Node.js 上，运行在 Bluemix 上运行在 CloudFoundry 上。

我正在查询一个 Cloudant 数据库，并获得返回的查询结果作为单个 JSON 数组包含所有文档作为 JSON 对象。

不，我想以流水线方式单独处理它们。这如何在 Node-RED 中实现？

非常感谢！

JSON

[{
  "id": "c8342b2a.bf0df",
  "type": "cloudant in",
  "z": "2f0a54f6.110ccc",
  "service": "nokeredrkie-cloudantNoSQLDB",
  "cloudant": "",
  "name": "",
  "database": "tweets",
  "search": "_all_",
  "design": "",
  "index": "",
  "x": 295.70001220703125,
  "y": 450.9333190917969,
  "wires": [
    ["5e83a34.48cdd5c"]
  ]
}, {
  "id": "c9411e75.2b1b7",
  "type": "debug",
  "z": "2f0a54f6.110ccc",
  "name": "",
  "active": true,
  "console": "false",
  "complete": "payload",
  "x": 646.699951171875,
  "y": 470.7333679199219,
  "wires": []
}, {
  "id": "3f1d2018.8f5ec8",
  "type": "inject",
  "z": "2f0a54f6.110ccc",
  "name": "",
  "topic": "",
  "payload": "",
  "payloadType": "date",
  "repeat": "",
  "crontab": "",
  "once": true,
  "x": 126.70001220703125,
  "y": 472.6666564941406,
  "wires": [
    ["c8342b2a.bf0df"]
  ]
}, {
  "id": "5e83a34.48cdd5c",
  "type": "function",
  "z": "2f0a54f6.110ccc",
  "name": "",
  "func": "//msg.payload = JSON.parse(msg.payload);\nmsg.payload = msg.payload[1].tweet.user.screen_name;\nreturn msg;",
  "outputs": 1,
  "noerr": 0,
  "x": 444.70001220703125,
  "y": 489.4000549316406,
  "wires": [
    ["c9411e75.2b1b7"]
  ]
}]

Answer 1

将 Cloudant 节点 输出到 函数节点，如下所示：

var msgs = [];
for (var i = 0; i< msg.payload.length; i++) {
  msgs.push({payload: msg.payload[i]});
}

return [msgs]

这会将数组中的每个项目流式传输到流中的下一个节点

编辑：需要将数组包装在另一组 [] 中，以使所有消息输出相同的输出。

如何将包含在一条消息中的 JSON 对象数组转换为多个 JSON 对象消息？

How can I transform a JSON array of object contained in one message to multiple JSON object messages?

javascript

json

node.js

node-red

ibm-cloud