C# 合并两个具有不同方案和 return 层次 json 的数据表

Question

我有一个动态的数据表，可以有 5-10 列。在下面的示例中，我只显示了 4 列。

DataTable dataTable = new DataTable();
            dataTable.Columns.Add("Name");
            dataTable.Columns.Add("America");
            dataTable.Columns.Add("Japan");
            dataTable.Columns.Add("Singapore");

            dataTable.Rows.Add("A", 200, 100, 300);
            dataTable.Rows.Add("B", 300, 300, 600);
            dataTable.Rows.Add("C", 400, 400, 700);
            dataTable.Rows.Add("D", 500, 500, 800);
            dataTable.Rows.Add("E", 600, 600, 900);
            dataTable.Rows.Add("F", 700, 700, 1000);
            dataTable.Rows.Add("G", 800, 800, 600);
            dataTable.Rows.Add("H", 900, 100, 400);
            dataTable.Rows.Add("I", 100, 200, 300);
            dataTable.Rows.Add("J", 200, 300, 200);
            dataTable.Rows.Add("K", 300, 500, 500);

此数据表保证有 Name 列，其他列可能出现也可能不出现。

我有一个映射数据表，它也有 Name 列（可用于连接两个数据表），它还有另外两列建立行之间的关系。

 DataTable mappingTable = new DataTable();
            mappingTable.Columns.Add("Name");
            mappingTable.Columns.Add("id");
            mappingTable.Columns.Add("parentID");


            mappingTable.Rows.Add("A", 1, null);
            mappingTable.Rows.Add("B", 2, 1);
            mappingTable.Rows.Add("C", 3, 1);
            mappingTable.Rows.Add("D", 4, null);
            mappingTable.Rows.Add("E", 5, 4);
            mappingTable.Rows.Add("F", 6, null);
            mappingTable.Rows.Add("G", 7, 6);
            mappingTable.Rows.Add("H", 8, 6);
            mappingTable.Rows.Add("I", 9, 1);
            mappingTable.Rows.Add("J", 10, null);
            mappingTable.Rows.Add("K", 11, 10);

目前我正在 returning JSON DataTable 使用：

var json = Newtonsoft.Json.JsonConvert.SerializeObject(dataTable);

它产生以下输出：

[
  {
    "name": "A",
    "america": "200",
    "japan": "100",
    "singapore": "300"
  },
  {
    "name": "B",
    "america": "300",
    "japan": "300",
    "singapore": "600"
  },
  {
    "name": "C",
    "america": "400",
    "japan": "400",
    "singapore": "700"
  },
  {
    "name": "D",
    "america": "500",
    "japan": "500",
    "singapore": "800"
  },
  {
    "name": "E",
    "america": "600",
    "japan": "600",
    "singapore": "900"
  },
  {
    "name": "F",
    "america": "700",
    "japan": "700",
    "singapore": "1000"
  },
  {
    "name": "G",
    "america": "800",
    "japan": "800",
    "singapore": "600"
  },
  {
    "name": "H",
    "america": "900",
    "japan": "100",
    "singapore": "400"
  },
  {
    "name": "I",
    "america": "100",
    "japan": "200",
    "singapore": "300"
  },
  {
    "name": "J",
    "america": "200",
    "japan": "300",
    "singapore": "200"
  },
  {
    "name": "K",
    "america": "300",
    "japan": "500",
    "singapore": "500"
  }
]

但不是 return 这种 JSON，我需要使用 Mapping DataTable 并在行和 return 之间建立关系 JSON 看起来像这个：

[{
        "name": "A",
        "america": "200",
        "japan": "100",
        "singapore": "300",
        "children": [{
                "name": "B",
                "america": "300",
                "japan": "300",
                "singapore": "600"
            }, {
                "name": "C",
                "america": "400",
                "japan": "400",
                "singapore": "700"
            }, {
                "name": "I",
                "america": "100",
                "japan": "200",
                "singapore": "300"
            }
        ]
    }, {
        "name": "D",
        "america": "500",
        "japan": "500",
        "singapore": "800",
        "children": [{
                "name": "E",
                "america": "600",
                "japan": "600",
                "singapore": "900"
            }
        ]
    }, {
        "name": "F",
        "america": "700",
        "japan": "700",
        "singapore": "1000",
        "children": [{
                "name": "G",
                "america": "800",
                "japan": "800",
                "singapore": "600"
            }, {
                "name": "H",
                "america": "900",
                "japan": "100",
                "singapore": "400"
            }
        ]
    }, {
        "name": "J",
        "america": "200",
        "japan": "300",
        "singapore": "200",
        "children": [{
                "name": "K",
                "america": "300",
                "japan": "500",
                "singapore": "500"
            }
        ]
    }
]

DataTable 的结构可以更改，因为我可能会获得更多或更少的列数。如何生成所需的 JSON 输出？

Answer 1

我不确定是否有使用 DataTable 关系执行此操作的优雅方法。如果您不能摆脱使用数据表，您可以手动将数据映射到您需要的结构中。这假设映射 table 中的 ID 始终与数据 table.

中的行号匹配

var data = dataTable.Rows.Cast<DataRow>()
    .Select(r => dataTable.Columns.Cast<DataColumn>().ToDictionary(c => c.ColumnName, c => r[c.ColumnName]))
    .ToList();
var mapping = mappingTable.Rows.Cast<DataRow>()
    .Where(r => !r["parentID"].Equals(DBNull.Value))
    .ToLookup(r => (int)r["parentID"], r => (int)r["id"]);

var output = new List<Dictionary<string, Object>>();
foreach (var group in mapping) {
    data[group.Key - 1].Add("children", group.Select(c => data[c - 1]).ToList());
    output.Add(data[group.Key - 1]);
}

var json = Newtonsoft.Json.JsonConvert.SerializeObject(output);

C# 合并两个具有不同方案和 return 层次 json 的数据表

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