How To Express'Aggregate Into' In C#
Jul 25, 2011I have a code in VB .NET:Aggregate item In items Into Sum(item.Value)
View 3 RepliesI have a code in VB .NET:Aggregate item In items Into Sum(item.Value)
View 3 RepliesGiven....
Public MasterList as IEnumerable(Of MasterItem)
Public Class MasterItem(Of T)
Public SubItems as IEnumerable(Of T)
End Class
I would like a single IEnumerable(Of T) which will iterate through all SubItems of all MasterItems in MasterList
I would like to think that there is a Linq facility to do this, or an extension method I am overlooking. I need a mechanism that works in VB9 (2008) and hence does not use Yield.
How to Aggregate field's numeric value..? in visual basic 2010.i am created a form with a datagridview and a textbox .datagridview binding with a table. in visual basic 2010 and SQL Server 2008R2
table fields and datagridview columns are like below
[Code]...
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 have 1 query with aggregate with condition using access
SELECT
HD.No,
SUM(IIf(DT.Status = 'A', 1, 0)) AS One,[code]...
i can run it in access but not in .Net QueryBuilder
1.print the cars which are fast moving cars.
i have written this code but it shows message Cannot have aggregate function in expression[code]...
I do have a datatable filled from a flatfile (say .txt). After the datatable is populated, I manipulate the data. After datamanipulation I want to do some analysis of the content of the datatable. For this analysis, I need to aggregate the data.
To keep it simple, let's say I have single orders of customers in the datatable and now I want to get the total order amount for each customer (SQL: SELECT Customer, Count(Ordervalue) FROM Ordertable GROUP BY Customer).
how to change this Linq to Entities (VB.Net) query to Group by L2_ID column and aggregate the calculated column diff as Sum for the group.
[Code]...
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]...
[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.
View 1 RepliesI am trying to aggregate a column in a datagridview. I know how to get it to work if I bind a database to it, I have several of them working perfectly, but I have one datagrid that is not bound to a database and for the life of me can not fiqure out
View 4 RepliesVB.NET .NET 3.5 I have an aggregate class called Package as part of a shipping system. Package contains another class, BoxType . BoxType contains information about the box used to ship the package, such as length, width, etc. of the Box.
Package has a method called GetShippingRates. This method calls a separate helper class, ShipRater, and passes the Package itself as an argument. ShipRater examines the Package as well as the BoxType, and returns a list of possible shipping rates/methods.
What I would like to do is construct an Interface, IRateable, that would be supplied to the helper class ShipRater. So instead of:
[Code]...
However, ShipRater requires information from both the Package and its aggregate, BoxType. If I write an interface IRateable, then how can I use the BoxType properties to implement part of the Interface?
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.
Given a table like
ID | Name | City
1 | X | Y
2 | Z | Y
[code].....
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:
[code].....
I've got a 2 part question: First question: I know that there is a query limit of 5,000 records when querying records, for performance reasons, but is there a limit when doing an aggregate query? If so, what is it? I need only to query the number of records and for one entity I can get a result of 39,000+ records, but for another entity I see an error message like:
[Code]...
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.
[Code]...
I am working on an application in Visual Basic Express using an Access 2000 database.I am trying to get athe following SQL query to work but get an error in Access.
The query is:
SELECT [ID], [Title], [Author], [Series], [YearPublished], [ISBN], [CoverPrice], [Style], [Condition], [Signed], [Comments], Count([Title]) AS CountOfBooks, Sum([CoverPrice]) AS TotalCoverPrice
FROM tblBooks
WHERE ID=[@ID];
The error is:"You have tried to execute a query that does not include the spec ified expression 'ID' as a part of the aggragate function."
The query works fine without the 'Count' and 'CoverPrice' count and sum to the query.
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
[code].....
I'm just using the default SQL Server Express in my vb 2008 express edition as my database server for my database operation. When I tried to update the records on my table I got a runtime error which indicates the error on this line 'myCommand.ExecuteNonQuery()'and it highlights a yellow background on it. The runtime error says "SqlException was unhandled: An expression of non-boolean type specified in a context where a condition is expected, near 'Number'. ".
Imports System.Data.SqlClient
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Dim myConnection As New SqlConnection
Dim myCommand As New SqlCommand
[code]....
I tried to start using VB 2010 Express with a program I originally developed with VB 2005 Express that I moved to VB 2008 Express successfully a couple years ago. It uses a database file (*.mdf) that is on the computer ( not out on a server). When attempt to run the program in debug mode, I get the following error "An attempt to attach an auto-named database for file C:Documents and SettingsTomMy DocumentsQuizzing StuffQuestion Database 2010QuizQuest ionGameQuizQuestionGameinReleaseQuizQuestionDB.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share."
I first made a copy of the entire project folder that was working in VB 2008 Express and gave it a different name. In VB2010 I opened the project in the copied folder and it said it successfully converted the project. I am able to open the Data Source inthe Designer and see the database structure as I expect. I think the project is still using SQL Server 2005 Express (because it is what is checked in the list of prerequisites on the Publish tab).
Note, I have programmed off and on for many years, but fairly new to using databases and SQL Server.
Is it possible to connect to a database on SQL Server R2 Express from Visual Basic Express? I am following a set of tutorial videos done in SQL Server 2005, but cannot seem to connect to create the database. I have created the database in SQL Server R2 Express, but cannot connect. Is there a work around?
View 4 RepliesHere is the scoop: I am trying to make a user account SQL database work with Visual Basic 2008 Express for login purposes, i.e. usernames & passwords. Plan is to host this server so people can login to use the the application and verify they have a valid account. I would like to host all the account information in SQL due to the possiblity of hundreds of users at any given time. I also need the ability to add data to the database for users registering for the first time. The SQL server will need to be able to access the SQL Server databases remote via WAN.
View 1 RepliesI am trying to re write a VB6 program using MS Access, many years ago, using VB 2010 express and SQL server 2008 R2 Express. I have a database with several tables, which I created using the designer. I am able to connect to the database and select data and display it in textboxes etc in vb code. What I have not been able to in code is to INSERT rows DELETE rows or UPDATE any data in the tables. I can do any of these operations using the Query Designer, but I want to do it in code. I can post some code if necessiary, but I thought it might just be some property that I had not set in the designer.
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Is VB Express 2010 slower to compile and run that older versions of VB Express? I've installed it this weekend and it seems a little sluggish on my quad core computer with 1 gig of RAM. I have VB Express 2005 installed for my students at school and it seems to fly just fine. Those school computers are older P4s with 512k of RAM.
View 7 Repliesthere Dream in Code Community! Im an okay programmer as far as skill right now I am still learning as we all are I need some help from some experienced VB.NET programmers in the community, Here is the scoop: I am trying to make a user account SQL database work with Visual Basic 2008 Express for login purposes, i.e. usernames & passwords.
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The program I am trying to modify was initially written using VB 2005 Express. I have subsequently downloaded the 2008 version. The program creates a monthly spreadsheet from a template. The old code that will no longer (highlighted and underlined) compile is as follows:
[Code]...
It's probably just a case of me not looking in the right place or not seeing the obvious, but does anyone know if a machine with just version 2.0 of the .NET Framework should be able to run a VB.NET Express application which accesses a SQL Server Express database file? Or is there an additional requirement for a non-development machine to have some kind of SQL Server Express runtime component in addition to the 2.0 Framework?It seems to be counterintuitive to expect that a VB.NET application would be able to access any kind of SQL Server data without having some kind of SQL Server host component (Express or otherwise) installed. But then again, it seems just as counterintuitive that Microsoft would require the download and installation of the new framework as well as a separate database runtime in order for the average user to run an application with accesses a local SQL Server Express database.To me, it runs contrary to the whole concept of XCopy deployment to require more than just the application's files and .NET Framework for an application to run properly. But nothing I've read so far explicitly indicates that a user would require anything more than the app files and the framework to run an application which accesses SQL Server Express data. But...I can't get any VB Express applications which uses a SQL Server Express databases to run on any machine that doesn't have SQL Server Express installed.What am I missing?(Apologies if this isn't the right group to post this in.
View 3 RepliesI have attempted to uninstall VB 2005 express and C++ express using Remove Add programs to no avail. Error message: The Window Installer Package c:program files visual studio 8 vs_setup.msi could not be opened. I have removed the MSDN library and SQL server successfully. I have also tried vs_uninst_betas tool which doesn't find anything to uninstall. I would prefer not to modify the registry if at all possible. If I could find a source for the original install packages for VB and C++ I would attempt reinstalling and then uninstalling....but cannot find them anywhere.
View 4 RepliesIs there any advantage to using the VB2010 express version versus the VB2008 express version? Can they be installed side by side or will VB2010 express replace VB2008? I have no issues with the 2008 version, so I don't know if installing the 2010 version would be of any advantage.
View 9 Replies