Linq complex queries C# - c#

i have this:
int item = particleEdges.ElementAt(i).Key;
Point3 hashPoint = particleEdges[item][j].hashEdge;
var hashList = particleEdges
.Where(p => p.Value.Any(q => q.hashEdge == hashPoint))
.Select(r => r.Key != item)
.ToList();
How to exclude "item" from hashList? Broke my head. Linq doesn't want to open to me.

var hashList = particleEdges
.Where(p => p.Value.Any(q => q.hashEdge == hashPoint))
.Where(r => r.Key != item)
.Select(s => s.Key)
.ToList();

Related

How to iterate over a list to build a Linq query

I have the following working query:
posts.Where(post =>
post.Fields
.Where(x =>
x.RegionId == "RecipeArticleDetails" &&
(x.FieldId == "RecipePrepTime" || x.FieldId == "RecipeCookTime")
)
.GroupBy(x => x.PostId)
.Select(x => new { ID = x.Key, Value = x.Sum(y => Convert.ToInt32(y.Value)) })
.Where(x => x.Value > 10 && x.Value < 40)
.Any()
)
List<string> suppliedTimes = new List<string>(){
"10-60","0-10"
};
I would like to replace Where(x => x.Value > 10 && x.Value < 40) so it looks up from a list of ranges:
List<string> suppliedTimes = new List<string>(){
"10-60","0-10"
};
My understanding is I can use select to iterate over the items:
posts.Where(post =>
suppliedTimes.Select(x => new {low = Convert.ToInt32(x.Split("-",StringSplitOptions.RemoveEmptyEntries)[0]), high = Convert.ToInt32(x.Split("-",StringSplitOptions.RemoveEmptyEntries)[1]) })
.Any( a =>
post.Fields
.Where(x =>
x.RegionId == "RecipeArticleDetails" &&
(x.FieldId == "RecipePrepTime" || x.FieldId == "RecipeCookTime")
)
.GroupBy(x => x.PostId)
.Select(x => new { ID = x.Key, Value = x.Sum(y => Convert.ToInt32(y.Value)) })
.Where(x => x.Value > a.low && x.Value < a.high)
.Any()
)
)
However this code results in the error:
could not be translated. Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by inserting a call to 'AsEnumerable', 'AsAsyncEnumerable', 'ToList', or 'ToListAsync'. See https://go.microsoft.com/fwlink/?linkid=2101038 for more information.
Please can someone explain how I can achieve this and why what I have isn't working.
To make it work with EF Core I would suggest my extnsion FilterByItems and change the way how to retrieve records.
List<string> suppliedTimes = new List<string>(){
"10-60","0-10"
};
var ranges = suppliedTimes
.Select(x => x.Split("-", StringSplitOptions.RemoveEmptyEntries))
.Select(x => new {
low = Convert.ToInt32(x[0]),
high = Convert.ToInt32(x[1])
});
var fields = context.Fields
.Where(x =>
x.RegionId == "RecipeArticleDetails" &&
(x.FieldId == "RecipePrepTime" || x.FieldId == "RecipeCookTime")
)
.GroupBy(x => x.PostId)
.Select(x => new { ID = x.Key, Value = x.Sum(y => Convert.ToInt32(y.Value)) })
.FilterByItems(ranges, (e, r) => e.Value > r.low && e.Value < r.high, true);
var posts = posts
.Join(fields, p => p.Id, f => f.ID, (p, f) => p);

Is there a way to set this entity/linq query to IEnumerable?

I'm trying to return an IEnumerable activities instead of "var"
var activities = ctx.Activities.Where(a => a.SiteID == propID)
.Where(a => a.ActivityTypeName == "Call")
.Select(x => new
{
x.DateTimeEntry,
x.Contact.OwnerContact.ParcelDatas
.FirstOrDefault(a => a.OwnerContactID == x.Contact.OwnerContact.OOwnerID)
.Parcel_LetterTracking.LMailDate,
x.FAQs.FirstOrDefault(a => a.ActivityID == x.ActivityID)
.FAQ_Library.FaqNum,
x.FAQs.FirstOrDefault(a => a.ActivityID == x.ActivityID)
.FAQ_Library.Question
});
edit: data type Object compiles but I'm not sure if that's right.
.Select already returns a an IEnumerable<TResult> also combine your ..where() clauses with && instead. https://learn.microsoft.com/en-us/dotnet/api/system.linq.enumerable.select?view=netframework-4.8 also one other thing you can do is use .AsEnuemerable()
var activities = ctx.Activities.Where(a => a.SiteID == propID && a.ActivityTypeName == "Call")
.Select(x => new
{
x.DateTimeEntry,
x.Contact.OwnerContact.ParcelDatas.FirstOrDefault(a => a.OwnerContactID == x.Contact.OwnerContact.OOwnerID).Parcel_LetterTracking.LMailDate,
x.FAQs.FirstOrDefault(a => a.ActivityID == x.ActivityID).FAQ_Library.FaqNum,
x.FAQs.FirstOrDefault(a => a.ActivityID == x.ActivityID).FAQ_Library.Question
}).AsEnumerable();

Adding more parameters to a Linq query

I'm using this query to count number of orders by date. I'm trying to add one more parameter that counts total products for each order, however I can't get it to work atm.
This is the essential part of a method that is suposed to return a list of 3 parameters (Date, TotalOrders and TotalProducts). Im using a Linq query to get a list with total order for each date, im wondering how to add my third parameter to the list "TotalProducts" and if i can do by adding one more search parameter in the Query. The foreach part below do not work propertly, it will return a list of TotalProducts but CreationDate will be the same for ech item in the list. I also have a feeling putting a foreach inside a foreach dosn't seem optimal for this:
var orders = _orderService.SearchOrderStatistics(startDateValue, endDateValue, orderStatus,
paymentStatus, shippingStatus, model.CustomerEmail, model.OrderGuid);
var result = orders.Where(o => o.PaymentStatus == PaymentStatus.Paid)
.GroupBy(g => g.CreatedOnUtc.Date.ToString("yyyyMMdd"))
.Select(s => new { Date = s.Key, Count = s.Count() });
List<GCOrdersModel> TotalOrdersPaid = new List<GCOrdersModel>();
foreach (var g in result)
{
foreach (var opv in orders)
{
GCOrdersModel _Om = new GCOrdersModel(g.Date, g.Count.ToString(), opv.OrderProductVariants.Count.ToString());
TotalOrdersPaid.Add(_Om);
}
}
return TotalOrdersPaid;
To access total products for every orders I must use OrderProductVariants.Count.ToString()
Can I add this parameter to the query?
Thx
You could try this:
return orders.Where(o => o.PaymentStatus == PaymentStatus.Paid)
.GroupBy(g => g.CreatedOnUtc.Date.ToString("yyyyMMdd"))
.Select(s => new GCOrdersModel()
{
Date = s.Key,
Count = s.Count(),
OpvCount = opv.OrderProductVariants.Count.ToString()
})
.ToList();
or
return orders.Where(o => o.PaymentStatus == PaymentStatus.Paid)
.GroupBy(g => g.CreatedOnUtc.Date.ToString("yyyyMMdd"))
.Select(s => new GCOrdersModel(s.Key, s.Count, opv.OrderProductVariants.Count.ToString()))
.ToList();
That way, you don't have to iterate over your result again. And it automatically creates your list of GCOrdersModel.
Edit
Does this work?
return orders.Where(o => o.PaymentStatus == PaymentStatus.Paid)
.GroupBy(g => g.CreatedOnUtc.Date.ToString("yyyyMMdd"))
.Select(s => new GCOrdersModel()
{
Date = s.Key,
Count = s.Count(),
OpvCount = s.OrderProductVariants.Count.ToString()
})
.ToList();
or
return orders.Where(o => o.PaymentStatus == PaymentStatus.Paid)
.GroupBy(g => g.CreatedOnUtc.Date.ToString("yyyyMMdd"))
.Select(s => new GCOrdersModel(s.Key, s.Count(), s.OrderProductVariants.Count.ToString()))
.ToList();
How about:
var opvCount =
opv
.OrderProductVariants
.Count
.ToString();
return
orders
.Where(o => o.PaymentStatus == PaymentStatus.Paid)
.GroupBy(g => g.CreatedOnUtc.Date.ToString("yyyyMMdd"))
.Select(s => new
{
Date = s.Key,
Count = s.Count()
})
.Select(x =>
new GCOrdersModelg(x.Date, g.Count.ToString(), opvCount));

Simplify if statement

How can I simplify such statement:
var someList = new List<someType>();
if (String.IsNullOrEmpty(groupId))
{
someList = CTX.Values.Include(c => c.Customer).ToList();
}
else
{
someList = CTX.Values.Include(c => c.Customer).Where(c => c.GroupId== groupId).ToList();
}
The difference is only in .Where(c => c.GroupId== groupId). Is it possible to include the condition String.IsNullOrEmpty(groupId) inside the query statement?
You can construct the query in multiple steps. Simply add the Where part only when groupId is not empty.
The query will only be executed once you call ToList().
var values = CTX.Values.Include(c => c.Customer);
if(!String.IsNullOrEmpty(groupId))
values = values.Where(c => c.GroupId == groupId);
someList = values.ToList();
Maybe this?
someList = CTX.Values.Include(c => c.Customer)
.Where(c => String.IsNullOrEmpty(groupId)
|| c.GroupId== groupId)
.ToList();
EDITED BY PLB REQUEST :)
bool isGroupValid = String.IsNullOrEmpty(groupId);
someList = CTX.Values.Include(c => c.Customer)
.Where(c => isGroupValid
|| c.GroupId== groupId)
.ToList();
You can add:
.Where(c => String.IsNullOrEmpty(groupId))
That is:
CTX.Values.Include(c => c.Customer)
.Where(c => c.GroupId == groupId || c => String.IsNullOrEmpty(groupId))
.ToList();

Resultant LinQ Query to a new DataTable

Refer to earlier post/Question:
LINQ to Swap few Columns to Rows of a DataTable using C#
I want the resultant of the query interms of a new dataTable directly instead of defining columns in the new datatable.
Refer to the above post question the LINQ Query newset is:
var newSet = dt.AsEnumerable()
.GroupBy(r => r.Field<string>("Location"))
.Select(g => new
{
Location = g.Key,
ppl_required_Q1 = g.Where(p => p.Field<string>("Quarter") == "Q1").Sum(p => p.Field<int>("ppl_required")),
ppl_required_Q2 = g.Where(p => p.Field<string>("Quarter") == "Q2").Sum(p => p.Field<int>("ppl_required")),
ppl_required_Q3 = g.Where(p => p.Field<string>("Quarter") == "Q3").Sum(p => p.Field<int>("ppl_required")),
ppl_required_Q4 = g.Where(p => p.Field<string>("Quarter") == "Q4").Sum(p => p.Field<int>("ppl_required")),
ppl_available_Q1 = g.Where(p => p.Field<string>("Quarter") == "Q1").Sum(p => p.Field<int>("ppl_available")),
ppl_available_Q2 = g.Where(p => p.Field<string>("Quarter") == "Q2").Sum(p => p.Field<int>("ppl_available")),
ppl_available_Q3 = g.Where(p => p.Field<string>("Quarter") == "Q3").Sum(p => p.Field<int>("ppl_available")),
ppl_available_Q4 = g.Where(p => p.Field<string>("Quarter") == "Q4").Sum(p => p.Field<int>("ppl_available")),
});
How to get the newset resultant collection in a new datatable directly without any loop through? Is it possible in LINQ??
Try this:
newset.CopyToDataTable();
Check this Link

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