父级和子级的数据表到具有层次结构的JSON格式

Question

I am trying to build a JSON output from the C# datatable. The single datatable contains parent and child as well. I would like to use LINQ to setup the JSON data, but would like to avoid creating classes since I have many such requirements and creating classes for each will be a burden.

Code

var obj = dt.AsEnumerable()
            .GroupBy(r => r["Head"])
            .ToDictionary(g => g.Key.ToString(),
                          g => g.Select(r => new {
                                                item = r["Item"].ToString(),
                                                quantity = (int)r["Quantity"]
                                             })
                                .ToArray());

var json = JsonConvert.SerializeObject(obj);

The above code provides the following output,

{
Sports : [
{item: 'Porsche 911', quantity: 100},
{item: 'Porsche 912', quantity: 200}
],
Luxury : [
{item: 'BMW 3 Series', quantity: 300}
],
Small :[
{item: 'Toyota Corolla', quantity: 400},
{item: 'Mitsubishi Lancer', quantity: 500},
{item: 'Mitsubishi Lancer 2', quantity: 600}
]}

But I want the following output

[
    {
        Head: 'Sports',
        total: 300,
        data : [
            {item: 'Porsche 911', quantity: 100},
            {item: 'Porsche 912', quantity: 200}
        ]
    },
    {
        Head: 'Luxury',
        total: 300,
        data : [
        {item: 'BMW 3 Series', quantity: 300}
        ]
    },
    {
        Head: 'Small',
        total: 1500,
        data :[
            {item: 'Toyota Corolla', quantity: 400},
            {item: 'Mitsubishi Lancer', quantity: 500},
            {item: 'Mitsubishi Lancer 2', quantity: 600}
        ]
    }
]

This post is a copy from Datatable with Parent and Child to JSON format . I wanted the data in a different format.

Answer 1

It can be written like this:

var obj = dt.AsEnumerable()
            .GroupBy(r => r["Head"])
            .Select(g => new
            {
                Head = g.Key.ToString(),
                total = g.Sum(x => (int)x["Quantity"]),
                data = g.Select(r => new
                {
                    item = r["Item"].ToString(),
                    quantity = (int)r["Quantity"]
                }).ToArray()
            })
            .ToList();


var json = JsonConvert.SerializeObject(obj);