DataWeave 转换：展平嵌套的 json 对象

Question

我想将以下输入传输为输出 JSON 格式。

并且密钥应该是动态的。我还有其他具有独特 JSON 结构的有效负载。

我该如何解决这个问题？

输入：

{"Report_Entry": [{
"Accepted_Currencies": "USD; EUR",
"Amount": "22",
"Lines": [{
"Project": "Proj1"
},{
"Project": "Proj2"
}],
"Amendments": [{
"Name": "Amd 1",
"Status": "Approved"
},{
"Name": "Amd 2",
"Status": "Approved"
}]
}]
}

输出：

[{
"Accepted_Currencies": "USD; EUR",
"Amount": "22",
"Project": "Proj1",
"Name": "Amd 1",
"Status": "Approved"
},{
"Accepted_Currencies": "USD; EUR",
"Amount": "22",
"Project": "Proj1",
"Name": "Amd 2",
"Status": "Approved"
},{
"Accepted_Currencies": "USD; EUR",
"Amount": "22",
"Project": "Proj2",
"Name": "Amd 1",
"Status": "Approved"
},{
"Accepted_Currencies": "USD; EUR",
"Amount": "22",
"Project": "Proj2",
"Name": "Amd 2",
"Status": "Approved"
}]

Answer 1

我假设 Report_Entry 中只有一个元素。在线和修改上嵌套地图将为您提供所需元素的组合。由于嵌套映射返回嵌套数组，因此顶部需要

flatMap()

或

flatten()

来展平两个映射的结果。

%dw 2.0
output application/json
var root=payload.Report_Entry[0]
---
root.Lines 
    flatMap ((line, line_index) -> 
        root.Amendments map ((amendment, amendment_index) -> 
        {
            Accepted_Currencies: root.Accepted_Currencies,
            Amount: root.Amount
        }
        ++ line 
        ++ amendment )
    )

输出：

[
  {
    "Accepted_Currencies": "USD; EUR",
    "Amount": "22",
    "Project": "Proj1",
    "Name": "Amd 1",
    "Status": "Approved"
  },
  {
    "Accepted_Currencies": "USD; EUR",
    "Amount": "22",
    "Project": "Proj1",
    "Name": "Amd 2",
    "Status": "Approved"
  },
  {
    "Accepted_Currencies": "USD; EUR",
    "Amount": "22",
    "Project": "Proj2",
    "Name": "Amd 1",
    "Status": "Approved"
  },
  {
    "Accepted_Currencies": "USD; EUR",
    "Amount": "22",
    "Project": "Proj2",
    "Name": "Amd 2",
    "Status": "Approved"
  }
]