Nested Linq in c#-CodePudding

I want to extract a list using linq as tree structure.

{
    "details": [
        {
            "description":"This is description 1",
            "Name": "Name 1"
        },
        {
            "description":"This is description 2",
            "Name": "Name 2"
        }
    ],
    "price": 100
}

I have one detailsDto as List<> in hand which i will use it in Details field

properties from 'm' instance will be bind in detailsDto. that's where i am facing problem on how to do it. description and name field available in 'm' instance

var data = await Task.FromResult((
    from c in _context.C
    join mc in _context.MC on c.VId equals mc.VId
    join m in _context.M on mc.Id equals m.mcId
    where mc.Id == mcId && c.Id == CId
    select new MainDto()
    {
        Price = mc.Price,
        // Details =
    }
    ).FirstOrDefault()
);

CodePudding user response：

Probably you need this query:

var data = await (
    from c in _context.C
    join mc in _context.MC on c.VId equals mc.VId
    where mc.Id == mcId && c.Id == CId
    select new MainDto()
    {
        Price = mc.Price,
        Details = _context.M.Select(m => new DetailsDto 
        {
            Name = m.Name,
            description = m.Description,
        }).ToList()
    }
    ).FirstOrDefaultAsync();

CodePudding user response：

this should be helpful

{
    Price = mc.Price,
    Details = m.Select(x => new DetailDto
    {
        Description = x.Description,
        Name = x.Name
    }).ToList()
}

It will create a new instance of the DetailDto class for each element in the m list and assign the values of the Description and Name properties to the corresponding properties in the DetailDto instance.