如何在DataWeave中按article汇总数组并计算ats_qty与最大po_date

需求说明 #

现有两个数组，需要按article字段进行汇总：

• 累加对应ats_qty的值
• 取该article对应的最大po_date值

输入数组 #

var array1 = [
    {
        "marketPlaceName": "A1",
        "article": "XX103030AE1100M",
        "ats_qty": "0",
        "po_date": "20230302"
    }
]

var array2 = [
    {
        "marketPlaceName": "A1",
        "article": "XX103030AE1100M",
        "ats_qty": "1",
        "po_date": "20230303"
    },
    {
        "marketPlaceName": "A1",
        "article": "XX103030AE1100L",
        "ats_qty": "2",
        "po_date": "20230302"
    }
]

实现代码 #

%dw 2.0
output application/json
var array1 = [
    {
        "marketPlaceName": "A1",
        "article": "XX103030AE1100M",
        "ats_qty": "0",
        "po_date": "20230302"
    }
]

var array2 = [
    {
        "marketPlaceName": "A1",
        "article": "XX103030AE1100M",
        "ats_qty": "1",
        "po_date": "20230303"
    },
    {
        "marketPlaceName": "A1",
        "article": "XX103030AE1100L",
        "ats_qty": "2",
        "po_date": "20230302"
    }
]
---
(array1 ++ array2) 
    groupBy ($.article) 
    pluck ((groupedItems, articleKey) -> {
        marketPlaceName: groupedItems[0].marketPlaceName,
        article: articleKey,
        ats_qty: (sum(groupedItems.ats_qty as Number)) as String,
        po_date: max(groupedItems.po_date)
    })

代码逻辑说明 #

1. 合并数组：用++运算符将两个输入数组合并为一个数组
2. 按article分组：使用groupBy函数，以article字段为键对合并后的数组分组
3. 聚合处理每组数据：通过pluck遍历分组结果，对每组数据做以下处理：
   • marketPlaceName：取分组中第一个条目的值（假设同一article对应的marketPlaceName一致）
   • article：直接使用分组的键值
   • ats_qty：先将每组的ats_qty转为数字类型求和，再转回字符串类型，匹配预期输出格式
   • po_date：利用max函数直接取每组中的最大值（因po_date是格式统一的日期字符串，字典序与日期顺序一致，可直接比较）

预期输出 #

[
    {
        "marketPlaceName": "A1",
        "article": "XX103030AE1100M",
        "ats_qty": "1",
        "po_date": "20230303"
    },
    {
        "marketPlaceName": "A1",
        "article": "XX103030AE1100L",
        "ats_qty": "2",
        "po_date": "20230302"
    }
]

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