LiNQ join two tables for substraction SUM - linq

Question

scenario : View should have sum of all profit , sum of all cost , and balance = profit - cost
public ProfitAndCostViewModel getTotalBalance()
{
var totalProfit = db.Profits.Where(p=>p.IdUser.UserId == WebSecurity.CurrentUserId).Sum(p=>p.Value);
var totalCost = db.Costs.Where(c=>c.IdUser.UserId == WebSecurity.CurrentUserId).Sum(c=>c.Value);
var balance = totalProfit - totalCost ;
return new ProfitAndCostViewModel { FinalBalance = balance };
}
controller:
public ActionResult Index()
{
var pcv = new ProfitAndCostViewModel();
pcv.ProfModel =getProfitSum();
pcv.CostModel =getCostSum();
pcv.TOTALBALANCE = getTotalBalance();
return View(pcv);
}
View:
#model WHFM.ViewModels.ProfitAndCostViewModel
#Model.FinalBalance.FinalBalance

Answer 1

Try this:
scenario : View should have sum of all profit , sum of all cost , and balance = profit - cost
public double getProfitSum()
{
return db.Profits.Where(p=>p.IdUser.UserId == WebSecurity.CurrentUserId).Sum(p=>p.Value);
}
public double getCostSum()
{
return db.Costs.Where(c=>c.IdUser.UserId == WebSecurity.CurrentUserId).Sum(c=>c.Value);
}
controller:
public ActionResult Index()
{
var pcv = new ProfitAndCostViewModel();
pcv.ProfModel = getProfitSum(); //This should be a double
pcv.CostModel =getCostSum(); //This should be a double
return View(pcv);
}
Model:
public class ProfitAndCostViewModel
{
public double ProfModel {get;set;}
public double CostModel {get;set;}
public FinalBalance {get{ return ProfModel - CostModel;} }
}
View:
#model WHFM.ViewModels.ProfitAndCostViewModel
#Model.FinalBalance - This show now be correct

Answer 2

try
public ProfitAndCostViewModel getTotalBalance()
{
var totalProfit = db.Profits.Where(p=>p.IdUser.UserId == WebSecurity.CurrentUserId).Sum(p=>p.Value);
var totalCost = db.Costs.Where(c=>c.IdUser.UserId == WebSecurity.CurrentUserId).Sum(c=>c.Value);
var balance = totalProfit - totalCost ;
return new ProfitAndCostViewModel{ FinalBalance = balance};
}
From what I can see, you are only looking for the final balance of the current user, right? If so, you don't need to return an IEnumerable of ProfitAndCostViewModel.
If you want to have a many to many user-balance output (an IEnumerable of ProfitAndCostViewModel) then try:
public IEnumerable<ProfitAndCostViewModel> getTotalBalance()
{
var result = from p in db.Profits
group p by p.IdUser.UserId
into g
join c in db.Costs on g.Key equals c.IdUser.UserId
group new {g,c} by g.Key into h
select new ProfitAndCostViewModel
{
FinalBalance = h.Select(x=>x.g.Sum(y=>y.Value)).First() - h.Sum(x=>x.c.Value),
UserId = h.Key
};
return result;
}
I only tested this on lists, not DB variables so it may not work.

Answer 3

public IEnumerable<ProfitAndCostViewModel> getTotalBalance()
{
var total = from p in db.Profits
join c in db.Costs on p.IdUser.UserId equals c.IdUser.UserId
group new { p, c } by p.IdUser.UserId into g
select new ProfitAndCostViewModel
{
FinalBalance = g.Sum(i => i.p.Value) - g.Sum(i => i.c.Value);
};
return total;
}

Answer 4

Try
public IEnumerable<ProfitAndCostViewModel> getTotalBalance()
{
var total = from p in db.Profits
join c in db.Costs on p.IdUser.UserId equals c.IdUser.UserId
where p.IdUser.UserId == WebSecurity.CurrentUserId
group new { p, c } by p.IdUser.UserId into g
select new ProfitAndCostViewModel
{
FinalBalance = g.Sum(i => i.p.Value) - g.Sum(i => i.c.Value)
};
return total;
}