Question

据说，我有一个LEFT JOIN查询返回的数据，我想通过Javascript格式化它。 ES6如何实现这一目标？

我们说我有这些数据：

{ 2, 4 }

对于每种材料，查询中都有一个行条目。

我想将它转换为具有相同进程的行将被转换为一个，但不同的材料放在其中的对象数组中：

[
    {
      "process_name": "Process 1",
      "bom_qty": 1.000000,
      "wip_qty": 20,
      "material_name": "Material 1",
      "material_id": "id 1",
      "process_id": 1
    },
    {
      "process_name": "Process 2",
      "bom_qty": 1.000000,
      "wip_qty": 11,
      "material_name": "Material 2",
      "material_id": "id 2",
      "process_id": 2
    },
    {
      "process_name": "Process 2",
      "bom_qty": 0.000003,
      "wip_qty": 11,
      "material_name": "Material 3",
      "material_id": "id 3",
      "process_id": 2
    },
    {
      "process_name": "Process 3",
      "bom_qty": "",
      "wip_qty": 58,
      "material_name": "Material 4",
      "material_id": "id 4",
      "process_id": 3
    },
    {
      "process_name": "Process 4",
      "bom_qty": "",
      "wip_qty": 58,
      "material_name": false,
      "material_id": "",
      "process_id": 4
    }
]

Answer 1

您可以使用array#reduce并创建一个以process_id为关键字的对象。对于每个唯一键，创建一个对象并添加所需的属性。之后，使用Object.values()提取所有值。

＆＃13;

var data = [ { "process_name": "Process 1", "bom_qty": 1.000000, "wip_qty": 20, "material_name": "Material 1", "material_id": "id 1", "process_id": 1 }, { "process_name": "Process 2", "bom_qty": 1.000000, "wip_qty": 11, "material_name": "Material 2", "material_id":"id 2", "process_id": 2 }, { "process_name": "Process 2", "bom_qty": 0.000003, "wip_qty": 11, "material_name": "Material 3", "material_id": "id 3", "process_id": 2 }, { "process_name": "Process 3", "bom_qty": "", "wip_qty": 58, "material_name": "Material 4", "material_id": "id 4", "process_id": 3 }, { "process_name": "Process 4", "bom_qty": "", "wip_qty": 58, "material_name": false, "material_id": "", "process_id": 4 } ],
    result = Object.values(data.reduce((r,{process_name, bom_qty, wip_qty, material_name, material_id, process_id}) => {
      r[process_id] = r[process_id] || {process_name, wip_qty, material : [], process_id};
      r[process_id].material.push({name: material_name,id: material_id, qty: bom_qty });
      return r;
    },{}));
console.log(result);

＆＃13;

Answer 2

您可以使用Array.prototype.map重新塑造您的收藏品像这样：

const data = [{
    "process_name": "Process 1",
    "bom_qty": 1.000000,
    "wip_qty": 20,
    "material_name": "Material 1",
    "material_id": "id 1",
    "process_id": 1
  },
  {
    "process_name": "Process 2",
    "bom_qty": 1.000000,
    "wip_qty": 11,
    "material_name": "Material 2",
    "material_id": "id 2",
    "process_id": 2
  },
  {
    "process_name": "Process 2",
    "bom_qty": 0.000003,
    "wip_qty": 11,
    "material_name": "Material 3",
    "material_id": "id 3",
    "process_id": 2
  },
  {
    "process_name": "Process 3",
    "bom_qty": "",
    "wip_qty": 58,
    "material_name": "Material 4",
    "material_id": "id 4",
    "process_id": 3
  },
  {
    "process_name": "Process 4",
    "bom_qty": "",
    "wip_qty": 58,
    "material_name": false,
    "material_id": "",
    "process_id": 4
  }
];
const newData = data.map(obj => ({
  process_name: obj.process_name,
  wip_qty: obj.wip_qty,
  material: {
    name: obj.material_name,
    id: obj.material_id,
    qty: obj.wip_qty
  }
}));

console.log(newData);

修改
我想念你想要的最终结果，我想你只想重新塑造结构现在我知道你也想要组合（分组）我写了另一个使用reduce和map的解决方案的对象。

Answer 3

映射数组需要一半。您仍然需要创建一个中间对象，其中process_id为键，对象为value。然后迭代它;如果密钥不存在，则将值推送到结果数组;如果存在，则将材质数组推送到现有数组。像这样的想法（在Sagiv的前一个代码之后添加它）：

const tmpObj = {}
newData.forEach(e => {
  if (tmpObj[e.process_id]) {
    tmpObj[e.process_id].material.push(e.material[0])
  } else {
    tmpObj[e.process_id] = e
  }
})
const resultArray = []
for (let key of Object.keys(tmpObj)) {
  resultArray.push(tmpObj[key])
}
console.log(resultArray)

来自LEFT Join的ES6格式数据

3 个答案: