Develop Reference

How to use linq to "flatten" an hierachy?

Given the following code example, how do I:
Get the commented out lines in the unfiltered list to work (without changing the definition of Result)?
Get the commented out lines in the filtered list to work (without changing the definition of Result)? From my maths it should give 32 records. Hopefully my output intent is clear enough for others to understand
Any questions feel free to ask
Regards
Kyle
//Populate data
var alphas = new List<Alpha>();
for (int a = 1; a <= 10; a++)
{
var alpha = new Alpha() { Id = a, Name = "A" + a };
for (int b = 1; b <= 10; b++)
{
var beta = new Beta() { Id = b, Name = "B" + b };
for (int c = 1; c <= 10; c++)
{
var charlie = new Charlie() { Id = c, Name = "C" + c };
for (int d = 1; d <= 10; d++)
{
var delta = new Delta() { Id = d, Name = "D" + d };
charlie.Deltas.Add(delta);
}
beta.Charlies.Add(charlie);
}
alpha.Betas.Add(beta);
}
alphas.Add(alpha);
}
//Get results into required format without filtering
var unfilteredResults = alphas.Select(a => new Result
{
AId = a.Id,
AName = a.Name,
//BId = a.Betas.Select(b => b.Id),
//BName = a.Betas.Select(b => b.Name),
//CId = a.Betas.Select(b => b.Charlies.Select(c => c.Id)),
//CName = a.Betas.Select(b => b.Charlies.Select(c => c.Name)),
//DId = a.Betas.Select(b => b.Charlies.Select(c => c.Deltas.Select(d => d.Id))),
//DName = a.Betas.Select(b => b.Charlies.Select(c => c.Deltas.Select(d => d.Name)))
});
var whiteListAIds = new List<int>() { 1, 2 };
var whiteListBIds = new List<int>() { 3, 4 };
var whiteListCIds = new List<int>() { 5, 6 };
var whiteListDIds = new List<int>() { 7, 8 };
//Get results into required format with filtering
var filteredResults = alphas.Where(a => whiteListAIds.Contains(a.Id)).Select(a => new Result
{
AId = a.Id,
AName = a.Name,
//BId = a.Betas.Where(b => whiteListBIds.Contains(b.Id)).Select(b => b.Id),
//BName = a.Betas.Where(b => whiteListBIds.Contains(b.Id)).Select(b => b.Name),
//CId = a.Betas.Where(b => whiteListBIds.Contains(b.Id)).Select(b => b.Charlies.Where(c => whiteListCIds.Contains(c.Id)).Select(c => c.Id)),
//CName = a.Betas.Where(b => whiteListBIds.Contains(b.Id)).Select(b => b.Charlies.Where(c => whiteListCIds.Contains(c.Id)).Select(c => c.Name)),
//DId = a.Betas.Where(b => whiteListBIds.Contains(b.Id)).Select(b => b.Charlies.Where(c => whiteListCIds.Contains(c.Id)).Select(c => c.Deltas.Where(d => whiteListDIds.Contains(d.Id)).Select(d => d.Id))),
//DName = a.Betas.Where(b => whiteListBIds.Contains(b.Id)).Select(b => b.Charlies.Where(c => whiteListCIds.Contains(c.Id)).Select(c => c.Deltas.Where(d => whiteListDIds.Contains(d.Id)).Select(d => d.Name)))
});
class Alpha
{
public int Id { get; set; }
public string Name { get; set; }
public List<Beta> Betas { get; set; } = new List<Beta>();
}
class Beta
{
public int Id { get; set; }
public string Name { get; set; }
public List<Charlie> Charlies { get; set; } = new List<Charlie>();
}
class Charlie
{
public int Id { get; set; }
public string Name { get; set; }
public List<Delta> Deltas { get; set; } = new List<Delta>();
}
class Delta
{
public int Id { get; set; }
public string Name { get; set; }
}
class Result
{
public int AId { get; set; }
public string AName { get; set; }
public int BId { get; set; }
public string BName { get; set; }
public int CId { get; set; }
public string CName { get; set; }
public int DId { get; set; }
public string DName { get; set; }
}

Got it working as below thanks to the first answer linq selectmany flatten multiple levels
Basically had to combine .SelectMany() on the "outer" parents and .Select() on the last/inner child.
//Populate data
var alphas = new List<Alpha>();
for (int a = 1; a <= 10; a++)
{
var alpha = new Alpha() { Id = a, Name = "A" + a };
for (int b = 1; b <= 10; b++)
{
var beta = new Beta() { Id = b, Name = "B" + b };
for (int c = 1; c <= 10; c++)
{
var charlie = new Charlie() { Id = c, Name = "C" + c };
for (int d = 1; d <= 10; d++)
{
var delta = new Delta() { Id = d, Name = "D" + d };
charlie.Deltas.Add(delta);
}
beta.Charlies.Add(charlie);
}
alpha.Betas.Add(beta);
}
alphas.Add(alpha);
}
var unfilteredResults = alphas.SelectMany(a => a.Betas.SelectMany(b=> b.Charlies.SelectMany(c=> c.Deltas.Select(d => new Result
{
AId = a.Id,
AName = a.Name,
BId = b.Id,
BName = b.Name,
CId = c.Id,
CName = c.Name,
DId = d.Id,
DName = d.Name
}))));
var whiteListAIds = new List<int>() { 1, 2 };
var whiteListBIds = new List<int>() { 3, 4 };
var whiteListCIds = new List<int>() { 5, 6 };
var whiteListDIds = new List<int>() { 7, 8 };
//Get results into required format with filtering
var filteredResults = unfilteredResults.Where(r => whiteListAIds.Contains(r.AId) && whiteListBIds.Contains(r.BId) && whiteListCIds.Contains(r.CId) && whiteListDIds.Contains(r.DId));
Console.WriteLine("Finished");
class Alpha
{
public int Id { get; set; }
public string Name { get; set; }
public List<Beta> Betas { get; set; } = new List<Beta>();
}
class Beta
{
public int Id { get; set; }
public string Name { get; set; }
public List<Charlie> Charlies { get; set; } = new List<Charlie>();
}
class Charlie
{
public int Id { get; set; }
public string Name { get; set; }
public List<Delta> Deltas { get; set; } = new List<Delta>();
}
class Delta
{
public int Id { get; set; }
public string Name { get; set; }
}
class Result
{
public int AId { get; set; }
public string AName { get; set; }
public int BId { get; set; }
public string BName { get; set; }
public int CId { get; set; }
public string CName { get; set; }
public int DId { get; set; }
public string DName { get; set; }
}

Select the last 4 posts of the site on the main page

I want to display the last 4 articles of the last site on the main page in a concise way. I have made a model view and I only have a problem with ef core.
ViewModel:
public class ShowBlogForHomePageViewModel
{
public int BlogId { get; set; }
public string BlogTitle { get; set; }
public string BlogUrl { get; set; }
public string BlogImageName { get; set; }
public string MetaDescriptionBlog { get; set; }
}
IBlogService:
List<ShowBlogForHomePageViewModel> GetBlogPostForHome();
BlogService:
public List<ShowBlogForHomePageViewModel> GetBlogPostForHome()
{
var ListBlogs= _context.Blogs.OrderByDescending(b => new ShowBlogForHomePageViewModel()
{
BlogId = b.BlogId,
BlogImageName = b.BlogImageName,
BlogTitle = b.BlogTitle,
MetaDescriptionBlog = b.MetaDescriptionBlog,
BlogUrl = b.BlogUrl
}).Take(4).ToList();
return null;
}
I think this part is true . please check it:
public List<ShowBlogForHomePageViewModel> GetBlogPostForHome()
{
return _context.Blogs.OrderBy(b=>b.BlogId).Select(b => new ShowBlogForHomePageViewModel()
{
BlogId = b.BlogId,
BlogImageName = b.BlogImageName,
BlogTitle = b.BlogTitle,
MetaDescriptionBlog = b.MetaDescriptionBlog,
BlogUrl = b.BlogTitle
}).TakeLast(4).ToList();
}

try this
public List<ShowBlogForHomePageViewModel> GetBlogPostForHome()
{
return _context.Blogs
.OrderByDescending(b => b.BlogId)
.Select(b => new ShowBlogForHomePageViewModel
{
BlogId = b.BlogId,
BlogImageName = b.BlogImageName,
BlogTitle = b.BlogTitle,
MetaDescriptionBlog = b.MetaDescriptionBlog,
BlogUrl = b.BlogUrl
}).Take(4)
.ToList();
}

Where is the mistake? Group by, join , select .net

I don´t know where is the mistake why it says that does not contain a defintion of ImporteSolicitado, interesesDemora and importeReintegro when they are colums of c and the last one of d
var importes = (from c in _context.ReintegroSolicitado
join d in _context.ReintegroRecibido on c.Expediente.ID equals d.Expediente.ID
group new {c,d} by new { c.Expediente.Codigo} into cd
select new { ImporteSolictadoFinal = cd.Sum(b => b.ImporteSolicitado + b.InteresesDemora), ImporteReintegroFinal = cd.Sum(e => e.ImporteReintegro) });

your group element contains two property c and d. So you need refer to
this property as
...
select new {
ImporteSolictadoFinal = cd.Sum(b => b.c.ImporteSolicitado + b.c.InteresesDemora),
ImporteReintegroFinal = cd.Sum(e => e.d.ImporteReintegro) }
...

This is very tough to get right with query posted. I did my best, but it is probably not exactly correct.
var importes = (from c in _context.reintegroSolicitado
join d in _context.reintegroRecibido on c.expediente.ID equals d.expediente.ID
select new { reintegroSolicitado = c, reintegroRecibido = c})
.GroupBy(x => new { c = x.reintegroSolicitado , d = x.reintegroRecibido})
.Select(cd => new { ImporteSolictadoFinal = cd.Sum(b => b.reintegroSolicitado.ImporteSolicitado + b.reintegroSolicitado.InteresesDemora), ImporteReintegroFinal = cd.Sum(e => e.reintegroRecibido.ImporteReintegro) });
}
}
public class Context
{
public List<ReintegroSolicitado> reintegroSolicitado { get; set; }
public List<ReintegroSolicitado> reintegroRecibido { get; set; }
public Expediente expediente { get; set; }
}
public class ReintegroSolicitado
{
public Expediente expediente { get; set; }
public int ImporteSolicitado { get; set; }
public int InteresesDemora { get; set; }
public int ImporteReintegro { get; set; }
}
public class Expediente
{
public int ID { get; set; }
public int Codigo { get; set; }
}

How to map objects

Here is my how my bindings currently look:
MerchantAccountRequest request = new MerchantAccountRequest
{
Individual = new IndividualRequest
{
FirstName = merchant.MerchantIndividual.FirstName,
LastName = merchant.MerchantIndividual.LastName,
Email = merchant.MerchantIndividual.Email,
Phone = merchant.MerchantIndividual.Phone,
DateOfBirth = merchant.MerchantIndividual.DateOfBirth,
Ssn = merchant.MerchantIndividual.Ssn,
Address = new AddressRequest
{
StreetAddress = merchant.MerchantIndividual.StreetAddress,
Locality = merchant.MerchantIndividual.Locality,
Region = merchant.MerchantIndividual.Region,
PostalCode = merchant.MerchantIndividual.PostalCode
}
},
Business = new BusinessRequest
{
LegalName = merchant.MerchantBusiness.LegalName,
DbaName = merchant.MerchantBusiness.DbaName,
TaxId = merchant.MerchantBusiness.TaxId,
Address = new AddressRequest
{
StreetAddress = merchant.MerchantBusiness.StreetAddress,
Locality = merchant.MerchantBusiness.Locality,
Region = merchant.MerchantBusiness.Region,
PostalCode = merchant.MerchantBusiness.PostalCode
}
},
Funding = new FundingRequest
{
Descriptor = merchant.MerchantFunding.Descriptor,
Destination = FundingDestination.BANK,
Email = merchant.MerchantFunding.Email,
MobilePhone = merchant.MerchantFunding.MobilePhone,
AccountNumber = merchant.MerchantFunding.AccountNumber,
RoutingNumber = merchant.MerchantFunding.RoutingNumber
},
TosAccepted = merchant.TosAccepted,
MasterMerchantAccountId = merchant.MasterMerchantAccountId,
Id = merchant.MerchantId
};
And I need to use AutoMapper to achieve the above.
This is what I've tried:
CreateMapperProfile
EDIT:
CreateMap<Classes.Merchant, MerchantAccountRequest>()
.ForMember(dest => dest.Individual, source => source.MapFrom(s => s.MerchantIndividual))
.ForMember(dest => dest.Business, source => source.MapFrom(s => s.MerchantBusiness))
.ForMember(dest => dest.Funding, source => source.MapFrom(s => s.MerchantFunding))
.ForMember(dest => dest.Id, source => source.MapFrom(s => s.MerchantId));
Here is the Merchant class:
public partial class Merchant :
{
public int Id { get; set; }
public string MerchantId { get; set; }
public virtual MerchantIndividual MerchantIndividual { get; set; }
public virtual MerchantBusiness MerchantBusiness { get; set; }
public virtual MerchantFunding MerchantFunding { get; set; }
public bool TosAccepted { get; set; }
public string MasterMerchantAccountId { get; set; }
public bool isSubMerchant { get; set; }
}
And the mappings;
EDIT:
MerchantAccountRequest request = _mapper.Map<MerchantAccountRequest>(merchant);
request.Individual = _mapper.Map<IndividualRequest>(merchant.MerchantIndividual);
request.Business = _mapper.Map<BusinessRequest>(merchant.MerchantBusiness);
request.Funding = _mapper.Map<FundingRequest>(merchant.MerchantFunding);
Can the first line of code MerchantAccountRequest request = _mapper.Map<MerchantAccountRequest>(merchant); above do all the mapings?
..
..
..
..
How can I create the correct mappings?

You don't need to call _mapper.Map on the properties of the request.
Just call MerchantAccountRequest request = _mapper.Map<MerchantAccountRequest>(merchant); and assuming you have a map for each type you should be fine.
I think something along the lines of the following should get you going down the right path.
class Program
{
static void Main(string[] args)
{
var config = new MapperConfiguration(cfg => {
cfg.CreateMap<Merchant, MerchantAccountRequest>()
.ForMember(dest => dest.Individual, c => c.MapFrom(source => source.MerchantIndividual));
cfg.CreateMap<MerchantIndividual, IndividualRequest>();
});
config.AssertConfigurationIsValid();
var mapper = config.CreateMapper();
var merchant = new Merchant
{
Id = 1,
MerchantIndividual = new MerchantIndividual { FirstName = "John Doe" }
};
var merchantAccountRequest = mapper.Map<Merchant, MerchantAccountRequest>(merchant);
}
}
public class Merchant
{
public int Id { get; set; }
public MerchantIndividual MerchantIndividual { get; set; }
}
public class MerchantIndividual
{
public string FirstName { get; set; }
}
public class MerchantAccountRequest
{
public int Id { get; set; }
public IndividualRequest Individual { get; set; }
}
public class IndividualRequest
{
public string FirstName { get; set; }
}

Linq SelectMany With Null Child

MenuSetup and AccessRules have a one to many relation as described below.
public class MenuSetup
{
public virtual int MenuId { get; set; }
public virtual string DisplayText { get; set; }
public virtual int MenuOrder { get; set; }
public virtual bool MenuStatus { get; set; }
public virtual bool HasKids { get; set; }
public virtual IList<MenuAccessRules> AccessRules { get; set; }
}
public class MenuAccessRules
{
public virtual int Id { get; set; }
public virtual Boolean CanCreate { get; set; }
public virtual Boolean CanUpdate { get; set; }
public virtual Boolean CanDelete { get; set; }
public virtual FamsRoles Roles { get; set; }
public virtual MenuSetup Menu { get; set; }
}
I want to project the result of the query below in a view model
var result = session.QueryOver<MenuSetup>()
.Where(p => p.MenuId == id)
.List();
var vs = result.SelectMany(x => x.AccessRules, (a, b) => new MenuDetailsViewModel
{
MenuId = a.MenuId,
DisplayText = a.DisplayText,
MenuOrder = a.MenuOrder,
HasKids = a.HasKids,
MenuStatus = a.MenuStatus,
AccessRuleLists = a.AccessRules.
Select(c => new AccessRulesList {
Id = b.Id,
MenuId = b.Menu.MenuId,
RoleId = b.Roles.RoleId,
CanCreate = b.CanCreate,
CanUpdate = b.CanUpdate,
CanDelete = b.CanDelete }).ToList()
}).SingleOrDefault();
When AccessRules has data, vs returns MenuDetailsViewModel, but when AccessRules is Empty vs returns null.
Please how do i craft my selectMany to return MenuDetailsViewModel irrespective of AccessRules data.
Thanks in advance for your help

Would something like this:
var vs = result.Select(x => new MenuDetailsViewModel
{
MenuId = x.MenuId,
DisplayText = x.DisplayText,
MenuOrder = x.MenuOrder,
HasKids = x.HasKids,
MenuStatus = x.MenuStatus,
AccessRuleLists = x.AccessRules == null ? null : x.AccessRules.
Select(c => new AccessRulesList
{
Id = c.Id,
MenuId = c.Menu.MenuId,
RoleId = c.Roles.RoleId,
CanCreate = c.CanCreate,
CanUpdate = c.CanUpdate,
CanDelete = c.CanDelete
}).ToList()
}).SingleOrDefault();

Check below code it may help
var vs = result.SkipWhile(a=> a.AccessRules==null).SelectMany(x => x.AccessRules, (a, b) => new MenuDetailsViewModel
{
MenuId = a.MenuId,
DisplayText = a.DisplayText,
MenuOrder = a.MenuOrder,
HasKids = a.HasKids,
MenuStatus = a.MenuStatus,
AccessRuleLists = a.AccessRules.
Select(c => new AccessRulesList {
Id = b.Id,
MenuId = b.Menu.MenuId,
RoleId = b.Roles.RoleId,
CanCreate = b.CanCreate,
CanUpdate = b.CanUpdate,
CanDelete = b.CanDelete }).ToList()
}).SingleOrDefault();