Linq To Sql, Aggregate Columns ,group By Date Into Listview?
Aug 3, 2011
also i have a table called Orders with several columns, they contain information about the order and store the ID of the Customer they belong to.Question is: how can i query that table with (preferably) linq (the datacontext is from LinqToSql) to return the following dataI want to search for any entry with the matching CustomerID which took place, group them by Year, Sum the Totals respectively and add them to the listview?I now i could use lamda expressions and aggregate, its just not clear how (option infer on,db is a datacontext object,CustomerID is an int32 variable):
Dim Orders = (From order In db.Orders Where order.CustomerID = CustomerID).GroupBy(Function(p) p.Date.Year).GetEnumerator
I reckon i'd have to create an anonymous type like the following:
I have the below Linq query that is returning the data but I need to aggregate the columns to group on the Period and Sum the Count columns. How do I go about doing this?
LINQ from t In tblTimes join h In tblEngineeringDashboard_CADMachinesCounts on t.ID Equals h.TimeID Order By t.Period
I have a list of attachments that I need to group by clientCLID and EmailAddress. From this grouped list I only need a list of clientCLIDs. After fiddling for a while I've managed to get it to work as follows:
The following data is created by joining two sql tables together:I would like to group together distinct rows of DateStamp/UserName/ StudentName/ InstructorName/TableName/PrimaryKey (I'll call this 'group records') and then group under these ColumnName/PreviousValue/NewValue (I'll call this 'subgroup records')The end result would be that I could iterate through the 'group records' - there would be 5. In each 'group record', I could then iterate through the 'subgroup records'. The 5 groups would contain 3, 2, 5, 2 and 1 subgroup records respectively.What would be the syntax to create a query to do this? Ideally this would be in a vb.net linq syntax.
I want to get the average of this query. From d In (From c In location.Descendants("temperature") Where c.Attribute("type").Value = "hourly" Select c).Descendants("value") Take 3 Select d I can see the aggregate keyword in the autocomplete dropdown, but how to apply it.
I've seen the operator Max used two different ways. The following two queries produce the same results. The MSIL code is slightly different. What is the benefit of using the Aggregate operator? Logically, is there a difference?
[code]The LINQ query going into "result" is incomplete because I'm stumped at what is happening there. I expect FirstOrDefault to refer to refer to a single Child object at that point in the expression, but it refers to a collection of child objects. Why? What is the best way to get a list of parents that have no associated child or have a child fitting a particular condition? (My actual code will have one child max, so this sample code is not representative.)I just don't understand what the collection of FirstOrDefault could be referring to. It should really be just 1 value or nothing at all times.
I'm having trouble getting my head around converting a traditional SQL aggregate query into a LINQ one. The basic data dump works like so:
Dim result = (From i As Models.InvoiceDetail In Data.InvoiceDetails.GetAll Join ih As Models.InvoiceHeader In Data.InvoiceHeaders.GetAll On i.InvoiceHeaderID Equals ih.ID
[CODE].....................
What I need to really be getting out is ih.Period (a value from 1 to 12) and a corresponding aggregate value for i.ExtendedValue. When I try to Group ih I get errors about i being out of scope/context.
I want to Sum of the calculated column Red which is calculated in the Function IsRed() that return an integer.When I run the query I get the following error: Method 'Int32 IsRed(Int32)' has no supported translation to SQL.How should I rewrite this to get it to work.
I have the following LINQ statement, which performs a simple linq query and assigns the resulting values labels on an asp.net web form:
Dim db As New MeetingManagerDataContext Dim q = From s In db.vwRoomAvailabilities _ Where s.MeetingID = lblMeetingID.Text _
[code]....
Originally, there was going to be only a single row result and you can see I'm using FirstOrDefault() to grab that single value which works great. But the design has changed, and multiple rows can now be returned by the query. I need to now Group By the MeetingID above, and SUM each of the selected columns (i.e. s.AllRequestedDoubles).
I have a list of object with 3 properties (quantity, service, name)I want to have all names and services in my list (kinda cross join) and the grouped quantity of the row corresponding. Not clear i guess
Quantity Service Name 3 Srv2 Bob 4 Srv2 Paul 2 Srv1 Paul 1 Srv2 Nick
I want as output All the services and all the names and corresponding quantities (0 if none)
Srv1 Paul 2 Srv1 Bob 0 Srv1 Nick 0
[code]....
Here is what I got so far, but I dont even get the expected resultsAnd I am acutally certain there is a pretty easy way of achieving what i want...
Dim services = (From a In interventions Select New With {.Service = a.Service}).Distinct() Dim months = (From b In interventions Select New With {.Month = b.DateHeureIntervention.Month}).Distinct() 'Dim query = (From s In services _
I have a table "People" with the following columns:
-FullName (nvarchar not null) -DOB (datetime null)
I want to write a LINQ to SQL to group the people by age, like following result:
Age 19: 4 ppl Age 20: 5 ppl Age 21: 6 ppl Here's my try: Dim query = From ppl In db.People _ Select New With {.Age = DateTime.Now.Year - CDate(ppl.DOB).Year, .CountAge = ppl.Count}
Notice that there are no DOB record for some people in the tables, so these shall not be included. The DOB column has record like this 1982-10-24 10:12:45 AM because it's a DateTime column.
I have a Linq Group By query that works. Here's the query:
Dim query = From fb As Feedback In lst Where fb.Seller.login_name.ToLower = UserName.ToLower Order By fb.transaction_id Descending, fb.creation Descending _
[Code]...
I don't like working with anonymous types so I'm trying to delare the result and am hitting an InvalidCastException.
I have a Linq Group By query that works. Here's the query:
Dim query = From fb As Feedback In lst Where fb.Seller.login_name.ToLower = UserName.ToLower Order By fb.transaction_id Descending, fb.creation Descending _ Group fb By fb.transaction_id _ Into Group
I don't like working with anonymous types so I'm trying to delare the result and am hitting an InvalidCastException.
So, armed with this information, here's the declaration used:
Dim query As IEnumerable(Of IGrouping(Of Int32?, IEnumerable(Of Feedback)))
Here's the error returned:
Unable to cast object of type 'System.Linq.GroupedEnumerable`4[Feedback,System.Nullable`1[System.Int32],Feedback,VB$AnonymousType_0`2[System.Nullable`1[System.Int32],System.Collections.Generic.IEnumerable`1[Feedback]]]' to type
I'm trying to figure out how to use Group Joins in LINQ queries under VB.net. For some reason, every example I seem to find on the syntax is just plain At least, that's what my compiler keeps telling me. This is a simple example where I want to join orders to their order items so that I end up with a type that contains a collection of order items grouped together by their orderId's:
Dim groupedOrders = (From o In orders Group Join i In orderItems On o.OrderId Equals a.OrderId Into myOrders Select o.OrderId, myOrders).ToList()
What I'm currently running into in this example is that the 'myOrders' group I'm creating errors out with: Definition of method 'myOrders' is not accessible in this context.
I am trying to write a module that will select cells from multiple, non-contiguous columns within a row that is defined by a variable. The column numbers are known and are unchanging. For example, my worksheet might look like this:
A B C D Row 1 X X X X
I want to select cells A1, B1, and D1; however, I don't want to use the row number (1 in this case) in my code. Rather, I want the row number to be specified as a variable. The code I am writing is inside a For/Next loop, so I would like to use the iterative variable (i in this case) to define the row number. That way, every iteration of the For loop will select cells from a different row.
I have a user input screen that allows them to select input values and the resulting query is dependent on which values the user entered. The resulting query groups up the results to present a list of unique customers
Simplified table design - A customer can be in many states [code...]
My head is fuzzled with this. I have an xml doc which has the layout for a grid stored in it. If you notice the columns are stored as "Items" in the XML. I am trying to retrieve each "Item" out of the XML using LINQ but no matter what I do I keep taking on straggler properties that I don't need.
I have the following query that groups parking spaces by their garage, but I can't figure out how to iterate the data in the view.
Public Function FindAllSpaces() Implements ISpaceRepository.FindAllSpaces Dim query = _ From s In db.spaces _ Order By s.name Ascending _
[code]....
The controller is taking the query object as is and putting it into the viewdata.model and as stated the view is not currently strongly typed as I haven't been able to figure out how to do this. I have run the query successfully in linqpad.
I spent a lot of time on this problem. I am able to do simple Group By LINQ queries (on one property) but for multiple fields I'm a little stuck... Here is a LINQPad sample of what I want to do :
dim lFinal={new with {.Year=2010, .Month=6, .Value1=0, .Value2=0}, new with {.Year=2010, .Month=6, .Value1=2, .Value2=1}, new with {.Year=2010, .Month=7, .Value1=3, .Value2=4},
I have to perform the following SQL query: select answer_nbr, count(distinct user_nbr) from tpoll_answer where poll_nbr = 16 group by answer_nbr The LINQ to SQL query
