I have a function that looks like this:
public void GetAvailableResourcesByLocationChart(List<DateTime> dates, List<ChartResourceModel> data)
{
var totals = (from r in data
group new { Dates = r.Dates } by r.Location into g
select new
{
Location = g.Key,
Dates = dates.Select(d => new
{
Date = d,
Available = g.SelectMany(x => x.Dates.Where(y => y.Date == d)).Count(x => x.Available)
})
.OrderBy(x => x.Date)
.ToList()
})
.OrderBy(x => x.Location)
.ToList();
}
This example groups the data based on Location. But I want to be able to pass in a string that specifies what it should group on. I was thinking DynamicLinq would be the right way to go about this but I'm having trouble reproducing it.
I started off doing this, but am getting stuck reproducing the SelectMany inside the select:
public void GetAvailableResourcesByLocationChart(List<DateTime> dates, List<ChartResourceModel> data, string grouping)
{
var totals = data.GroupBy(grouping, "it").Select("new (it.Key as Group, it as Dates)").Cast<dynamic>();
}
Any ideas on what I need to do next?
this
from r in data
group new { Dates = r.Dates } by r.Location into g
...
is the same as this
data.GroupBy(r => r.Location, b => b.Dates)
so if we have variable named grouper
data.GroupBy(r => {
if (grouper == "L")
return r.Location
else
return r.Dates }, b => b.Dates);
This should get you on the right track?
Related
I have following query:
select concat(Left(DateName(month,[date]),3), ' ', Year([date])),
sum(TotalAttendants) as Total,
Sum(FemaleAttendants) as Women,
Sum(MaleAttendants) as Men
from dbo.Events
where IsDeleted=0 and EventTypeId = 1
group by concat(Left(DateName(month,[date]),3), ' ', Year([date]))
and I want to transform it to c# linq lambda expression.
I tried something like this:
var response = await _context.Events
.Where(x => !x.IsDeleted && x.EventTypeId == Domain.Enums.EventTypes.DirectBeneficiaries)
.GroupBy(x => x.Date)
.Select(x => new EventViewData
{
MaleAttendants = x.Sum(u => u.MaleAttendants),
FemaleAttendants = x.Sum(u => u.FemaleAttendants),
TotalAttendants = x.Sum(u => u.TotalAttendants),
MonthName = x.Key.ToString("00")
}).ToListAsync();
Im not getting same result as Im getting in my mssql management studio.
If you need more information about data structure and table Events here is the my another stackoverflow topic: link
I think you should group by month and year and do the formatting (concat, etc.) later (if needed at all).
select
...
from dbo.Events
..
group by Month([date]), Year([date]))
Then in linq you can:
...
.GroupBy(x => new { Year = x.Date.Year, Month = x.Date.Month } )
.Select(x => new // Note no type name
{
MaleAttendants = x.Sum(u => u.MaleAttendants),
FemaleAttendants = x.Sum(u => u.FemaleAttendants),
TotalAttendants = x.Sum(u => u.TotalAttendants),
Month = x.Key.Month,
Year = x.Key.Year
})
.ToListAsync() // Hit the db
.Select( x => new EventViewData
{
x.MaleAttendants
x.FemaleAttendants
x.TotalAttendants
MonthName = System.Globalization.CultureInfo.CurrentCulture.DateTimeFormat.GetAbbreviatedMonthName(x.Month)
...
}
I don't think GetAbbreviatedMonthName is supported by EF so we need to do it after ToListAsync.
I have two List row1 and row2.This is data for row1:
and data for row2:
I Concatenate these two lists into one :
var rows = rows1.Concat(rows2).ToList();
The result would be this:
and then want to groupBy on a few fields and order by with other fields.and do some changes to some data. This is my Code
var results = rows.GroupBy(row => new { row.FromBayPanel, row.TagNo })
.SelectMany(g => g.OrderBy(row => row.RowNo)
.Select((x, i) =>
new
{
TagGroup = x.TagGroup,
RowNo = (i == 0) ? (j++).ToString() : "",
TagNo = (i == 0) ? x.TagNo.ToString() : "",
FromBayPanel = x.FromBayPanel,
totalItem = x.totalItem
}).ToList());
which brings me back this result:
This is not what I really want I want to have this result. I Want all data with same "FromBayPanel" be listed together.
which part of my code is wrong?
I think when you want to order the elements within your group you have to use a different approach as SelectMany will simply flatten your grouped items into one single list. Thus instead of rows.GroupBy(row => new { row.FromBayPanel, row.TagNo }).SelectMany(g => g.OrderBy(row => row.RowNo) you may use this:
rows.OrderBy(x => x.FromBayPanel).ThenBy(x => x.TagNo) // this preserves the actual group-condition
.ThenBy(x => x.RowNo) // here you order the items of every item within the group by its RowNo
.GroupBy(row => new { row.FromBayPanel, row.TagNo })
.Select(...)
EDIT: You have to make your select WITHIN every group, not afterwards:
rows.GroupBy(row => new { row.FromBayPanel, row.TagNo })
.ToDictionary(x => x.Key,
x => x.OrderBy(y => y.RowNo)
.Select((y, i) =>
new
{
TagGroup = y.TagGroup,
RowNo = (i == 0) ? (j++).ToString() : "",
TagNo = (i == 0) ? y.TagNo.ToString() : "",
FromBayPanel = x.FromBayPanel,
totalItem = y.totalItem
})
)
EDIT: Test see here
How can I transform this SQL query to LINQ?
SELECT eg.Name Name, sum(bi.PlannedAmount) Amount
FROM BudgetItem bi, Expense e, ExpenseGroup eg
WHERE Discriminator = 'ExpenseItem' AND
bi.ExpenseId = e.Id AND
e.ExpenseGroupId = eg.id AND
bi.MonthlyBudgetId = 1
GROUP BY eg.Name
So far I've come up with this line:
var result = context
.ExpenseGroups
.GroupBy(eg => eg.Id, (s) => new { Name = s.Name, Amount = s.Expenses.SelectMany(e => e.Items).Sum(i => i.PlannedAmount) })
.ToList();
But I still cannot figure out what expression to use to add 'bi.MonthlyBudgetItem = 1'.
Does anybody have an Idea?
Edit #1:
I forgot to mention the relationships between the entities. Every ExpenseGroup has many Expenses, and every Expense has many BudgetItems.
So, ExpenseGroup => Expenses => BudgetItems
Edit #2:
I'm using Entity Framework and every ExpenseGroup has a Collection of Expense objects (every Expense has a ExpenseGroup object), as well as every Expense has a Collection of BudgetItem objects (every BudgetItem object has a Expense object).
I suppose something like this should do it:
var result = context
.ExpenseGroups
.Where(x => x.Discriminator == 'ExpenseItem' &&
x.bi.ExpenseId == e.Id &&
x.e.ExpenseGroupId == eg.id &&
x.bi.MonthlyBudgetId == 1)
.GroupBy(eg => eg.Id, (s) => new { Name = s.Name, Amount = s.Expenses.SelectMany(e => e.Items).Sum(i => i.PlannedAmount) })
.ToList();
Something similar to this...
var result = (from g in context.ExpenseGroups
where g.Expense.BudgetItem.MonthlyBudgetId == 1
select g)
.GroupBy(eg => eg.Id, (s) => new { Name = s.Name, Amount = s.Expenses.SelectMany(e => e.Items).Sum(i => i.PlannedAmount) })
.ToList();
or
var result = context.ExpenseGroups
.Where(g => g.Expense.BudgetItem.MonthlyBudgetId == 1)
.GroupBy(eg => eg.Id, (s) => new { Name = s.Name, Amount = s.Expenses.SelectMany(e => e.Items).Sum(i => i.PlannedAmount) })
.ToList();
You are actually doing an inner join in your SQL query, so do similarly in your linq query as well. This should work:-
var result = from bi in context.BudgetItem
join e in context.Expense
on bi.ExpenseId equals e.Id
where bi.MonthlyBudgetId == 1
join eg in ExpenseGroup
on e.ExpenseGroupId equals eg.id
group new { bi, eg } by eg.Name into g
select new
{
Name = g.Key,
Amount = g.Sum(x => x.bi.PlannedAmount)
};
I have this function:
/// <summary>
/// Return array of all badges for a users
/// </summary>
public static Badge[] getUserBadges(int UserID)
{
Badge[] ReturnBadges;
using (MainContext db = new MainContext())
{
var q = db.tblBadgeUsers
.Where(c => c.UserID == UserID)
.GroupBy(c => c.BadgeID)
.Select(c => new { BadgeCount = c.Count(), TheBadge = c });
ReturnBadges = new Badge[q.Count()];
int i = 0;
foreach (var UserBadge in q)
{
ReturnBadges[i] = new Badge(UserBadge.TheBadge.Key);
ReturnBadges[i].Quantity = UserBadge.BadgeCount;
i++;
}
}
return ReturnBadges;
}
I wish to order by tblBadges.OrderID ascending but I can't seem to find out where to put it, can anyone help?
I've tried:
.OrderBy(c=> c.TheBadge.OrderID)
But it's not valid code. TheBadge.Key in the loop is a tblBadges type. It's confusing me a bit why intellisense wont let me do the order by anywhere!
TheBadge isn't a single badge, it's a group of badges... so I'd personally rename it if I were you. Now, which OrderId do you want to get? You've got multiple entities in the gruop. For example, you could do this:
var q = db.tblBadgeUsers
.Where(c => c.UserID == UserID)
.GroupBy(c => c.BadgeID)
.Select(c => new { BadgeCount = c.Count(), TheBadge = c })
.OrderBy(x => x.TheBadge.First().OrderId);
That will order by some notional "first" element - although I don't know what the generated SQL will look like.
If you expect the OrderId to be the same for every badge with the same ID, you might use:
var q = db.tblBadgeUsers
.Where(c => c.UserID == UserID)
.GroupBy(c => new { c.BadgeID, c.OrderID })
.OrderBy(group => group.Key.OrderID)
.Select(c => new { BadgeCount = c.Count(), TheBadge = c });
Try this:
var q = db.tblBadgeUsers
.Where(c => c.UserID == UserID)
.GroupBy(c => c.BadgeID)
.Select(c => new { BadgeCount = c.Count(), TheBadge = c.Key }) // *mod
.OrderBy(c=> c.TheBadge.OrderID); // * added
In the following line, TheBadge is a linq collection, not the badge itself. You want c.Key.
.Select(c => new { BadgeCount = c.Count(), TheBadge = c })
I am using GroupBy create a hierarchical set of groups to use in multiple child grids.
Assume I have a query with with 6 columns, a, b, c, d, e, f.
Now, I need to group by a, then by b, then by c. and return the entire row in the group of c's.
var q = rows.GroupBy(x => x.a)
Ok, that's nice. That gives me my group of a's. Next, we look to group them by a and b.
var q1 = q.Select(g =>new {
Key = g.Key,
SubGroup = g.GroupBy(x => x.b)
}
Ok, that also works nice. I get my group of a's with subgroups of b's.
Now I'm stumped at the third level. I've tried various syntaxes, but most won't even compile. The ones that do do not give the correct results.
var q2 = q1.Select(g1 => new {
Key = g1.Key,
SubGroup = g1.GroupBy(x => x.c)
}
This doesn't compile. Tells me that there is no GroupBy on g1.
var q2 = q.Select(g1 => new {
Key = g1.Key,
SubGroup = g1.GroupBy(x => x.c)
}
This doesn't give me the b subgroup, only the a and c.
Any idea of what i'm doing wrong here?
EDIT:
The Following also does not work, saying there is no definition for the g1.Key
var q2 = q.Select(g => new {
Key = g.Key,
SubGroup = g.Select(g1 => new {
Key = g1.Key
SubGroup = g1.GroupBy(a => a.c)
})
I have such a poor grasp on what this is doing internally.
Now, I'm not saying this is actually a good approach; it's probably going to be slow and the right way to do this, if performance matters, may be to sort the whole collection by these different criteria and then look at the different parts of the sorted collection.
But if you want to use GroupBy and IGroupings to manage it, you're working at it from the wrong end. You want to start at the deepest level first and work up.
var groups = rows
.GroupBy(x => new { x.A, x.B, x.C, x.D, x.E, x.F })
.GroupBy(x => new { x.Key.A, x.Key.B, x.Key.C, x.Key.D, x.Key.E })
.GroupBy(x => new { x.Key.A, x.Key.B, x.Key.C, x.Key.D, })
.GroupBy(x => new { x.Key.A, x.Key.B, x.Key.C })
.GroupBy(x => new { x.Key.A, x.Key.B })
.GroupBy(x => x.Key.A);
groups.First().Key; // will be an A value
groups.First().First().First(); // will be an A, B, C group
GroupBy actually supports giving a list of elements to group by. Each group will contain the same first 3 items (A, B & C). You can get the key with the .Key method, and play around with the different rows with foreach. See Example:
var groups = Elements.GroupBy(x => new {x.A, x.B, x.C});
foreach (var group in groups)
{
Trace.WriteLine(group.Key + ": " + group.Count());
foreach (var row in group)
{
Trace.WriteLine(row.D);
}
}
Edit: Ahh, ok - what you need is this then:
var groups = Elements
.GroupBy(a => new {a.A})
.Select(g1 => new {
A = g1.Key,
Groups = g1
.GroupBy(b=> new {b.B})
.Select(g2 => new {
B = g2.Key,
Groups = g2
.GroupBy(c => new {c.C})
.Select(g3 => new {
C = g3.Key,
Rows = g3
})
})
});
foreach (var groupA in groups)
{
Trace.WriteLine(groupA.A);
foreach (var groupB in groupA.Groups)
{
Trace.WriteLine("\t" + groupB.B);
foreach (var groupC in groupB.Groups)
{
Trace.WriteLine("\t\t" + groupC.C);
foreach (var row in groupC.Rows)
{
Trace.WriteLine("Row: " + row.ToString());
}
}
}
}