Combining Objects Through Summation Of One Field Only
Aug 1, 2011
I have a set of objects that I'm returning via a Linq to SQL query. I'd like to modify the query so that I return a set of objects that are combined only when one of the fields match. The relevant columns of my Products DB table are CategoryID and Quantity. I'd like to combine the fields so that if the CategoryID is identical, the Quantity fields are summed up. However, I don't just want the sum - I need an object that has all the common fields (assume all other fields are identical for the query) so it appears as only one object of type Product. Is this possible? (I'm using VB.net - but open to solutions that include database views, partial classes, etc)
I would like to show a mathematical summation in a rich text box, using the standard mathematical notation that shows a Greek capital sigma, with the starting value of n below the sigma and an infinity sign above it. I have successfully done this using the code below, but I cannot get the infinity sign closer to the sigma. It looks like it is not part of the summation notation.
Does anyone have an idea how I can get the infinity sign lower? When I use a character offset to lower it, it also lowers the lines below it, so that the distance between the infinity sign and the sigma remains unchanged.
but how I'm going to view the total value of the summation? I had been searching for this but most of the answers I get is for PHP. Can someone show me how to assign that total value to a variable in VB.NET?
Or teach me how to assign that total value to another table.
So i run a loop that is an iteration for array variables. for i = 1 to 1000summation = summation + array(i)next iyet for every iteration, array(i) contains a different set elements, and I need to know the sum of these elements for every iteration step.For some reason VB saves the values from previous iteration(s) and adds them to the new.The question is: how do I sum a new set of array elements for every iteration without using the older values.? Can I: dim array(number of elements as a function of something) ?
How do you average certain records and then do the summation in a single or separate SQL statements? For example, you want to average learner marks below 50 and the sum all marks for every learner in the table. If this needs two separate statements please help me with the averaging statement.
I'm a long time VB.NET developer and has recently switched to C#. I found out that some of the built-in VB.NET functions (which predates .NET back to 6.0 and BASIC itself) such as the String.Left, or Right, or advanced functions like saving to the registry (SaveSettings and GetSettings) are noticeably absent. What I did was create a new project in the same solution with VB.NET as its language and recreate basically all the functions I need that are available in VB.NET. And then I just call that to the C# code I'm writing.Since compiling the code in .NET pretty much boils down to the same CIL, it shouldn't matter performance-wise what language I wrote the code in or whether I mix C# with VB.
I am getting this error, Not sure why it is happening "Error The SqlParameterCollection only accepts non-null SqlParameter type objects, not Int32 objects."I have tried with all sorts of possibilties, now try to enter default data as dummy data,
Using connection As New SqlConnection connection.ConnectionString = ConfigurationManager.ConnectionStrings("DentalDeviceConnectionString").ConnectionString connection.Open()[code].....
I want to let the user input objects to a richtextbox 1 object on each line, and somehow use Random.Next to select pseudorandomly a few objects, the number 'few' inputted in a textbox.
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Using conn As New SqlConnection("Database=Clinic_Management_System;Data Source=.SQLExpress;Integrated Security=True;AttachDBFilename=|DataDirectory|Clinic Management System.mdf") Dim cmdRecord As SqlCommand
I have a user control that inherits the FW ListView and I need to dispose of two objects when the form's disposing of it's objects. Here's what I've concluded already, am I on the right track?
I'm trying to write 2 extension methods to handle Enum types.One to use the description attribute to give some better explanation to the enum options and a second method to list the enum options and their description to use in a selectlist or some kind of collection.You can read my code up to now here:
<Extension()> _ Public Function ToDescriptionString(ByVal en As System.Enum) As String Dim type As Type = en.GetType Dim entries() As String = en.ToString().Split(","c)
[code]....
So my problem is both extension methods don't work that well together. The methods that converts the enum options to an ienumerable can't use the extension method to get the description.
I'm working with a third-party library interfacing to an old database system. There's a method - CallProg that calls a "stored procedure" (for lack of a better translation - any Pick users in the crowd?). However, instead of doing something like this:
Public Sub CallProg(ProgName, ParamArray ProgArgs() As String) ... End Sub
I have 3 textbox's and 1 dropdownlist and I am trying to combine all that data into one string. Here is what I tried but is not working:
Private Sub FullAddressTextBox_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles FullAddressTextBox.TextChanged FullAddressTextBox.Text = AddressTextBox.Text & " , " & CityTextBox.Text & " , " & StateDropdown.text " , " & ZipCodeTextBox.Text End Sub
My goal is to combine these simultaneously as whoever is filling in the data or after I hit my submit button, if so it has to occur as the first event.
I think my problem has to do with .text after the statedropdown, Is it suppose to be .tostring?
I've seen several posts on the subject, but none seem to answer this particular dilemma. I have two datatables that I obtained by querying two separate servers.[code]
I have two (actually many) .png images in my application. Both have transparent areas here and there.I want, in my application, to take both images, combine them, and display the result in a picture box. Later I want to save the result through a button.So far I managed to find the two images and combine them, but it seems the transparency thing won't work. I mean, if you put one image over another, only the top image is visible as the result because, apparently, the image's background is a plain white box. Which is not. Here is a bit of my code:
Dim Result As New Bitmap(96, 128) Dim g As Graphics = Graphics.FromImage(Result) Dim Name As String[code]....
resourcesPath is the path to my resources folder. Bases is a folder in it. And Name is the image's name.
How to combine these two conditions in one section Private Sub DataGridView1_CellValidating(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellValidatingEventArgs) Handles DataGridView1.CellValidating 'condition 1 ' check given value is numeric or charactr type If e.ColumnIndex = 3 Then If Not IsNumeric(e.FormattedValue) Then DataGridView1.Rows(e.RowIndex).ErrorText = " must be a numeric value" [Code] ..... 'condition 2 ' check given value is greater than 0 or not If e.ColumnIndex = 3 Then If (e.FormattedValue.ToString = "0") Then [Code] .....
Let's say I have 3 tables: carts, baskets and eggs where a basket can contain many eggs and where carts contain many baskets. Each basket has a foreign key that maps to a cart and each egg has a foreign key that maps to a basket.I need to return a table that contains these 3 columns:Cart Name | Count of Baskets in Cart | Count of Eggs in Cart.Each table is an EF and I'm using linq with VB.So far, I have 2 queries: one that returns the columns Cart Name and Count of Basket and another one that returns Cart Name and Count of Eggs. How can I combine these two result tables so that I get the results in one table?
Dim query1 = (From cart In myEntities.Carts Where cart.UserID = TheUserID Join baskets In myEntities.Baskets On baskets.CartID Equals cart.CartID
I'm trying to combine two arrays. Simply append 1 array to another. I have two string arrays. Lets just say array1 and array2.would the following be correct?
array1.Copy(array1, array2, UBound(array1)) I guess I'm slightly confused about the parameters. When I try to use the above code I get green squigglies with the following error.Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated.
this is my code right now i want to make it so that it will keep adding the total. meaning if i get an answer then get another answer i want both of them to add up and show.how can i change it so that it will do tat??
long story short, I have created a ListView type control, using UserControls for the parent control and the ListViewItems. Most the of the control is written and works fine, right up to the point where I tried to replicate the 'Control.SelectedItems(0).Index' property and the 'SelectedIndexChanged' event.
Each child object knows its index value, and could pass this value via the SelectedIndexChanged event (assuming this is how it works in a normal ListView control -- user clicks on an item, and that item fires an event updating the selected index value in the parent object).
How does the child object raise an event in the parent object? I have a feeling this could be done with Delegates, but I'm still learning about their usage.
I originally developed a simple application software [VB.Net + MS Access] (Lets call this project A) but now I want to include more functionality in it. I have an encryption/ decryption software utility (Lets call this project B ) and a Text to speech generation utility(Lets call this project C) . That is, I want to add Projects B and C to project A. [Such that clicking on the main form of project A calls a form from project B or C as desired].In solution explorer, I right clicked--Add Existing Project--and added both the above mentioned projects 1 by 1. (Added B and C to the solution explorer with the already present A).As the application software's (Project A's) main form is the main form of my project, I want to have a menu option on the main form (Of Project A) so that a user could click on one of the menu options and the main form of my other projects ( Project B or Project C or Encrypt/Decrypt or Voice Generation) should open by him doing so. To this effect, I tried the following:
1. I dragged the form simply from one of the projects (From B or C ) into the folder of my Application Software (Project A).This generated a lot of Build errors and the Voice Generation utility (Prj. C) would not work like this.
2. Tried to reference a dll, however the authors of Projects B and C did not include a dll in their projects.
3. Now I came to know that to call a form residing in another project folder or even another folder within the same project, you have to give a path for the form. HOW DO WE DO THIS?
As you can understand, I cannot copy the entire code of the 3 projects here....I will try attaching my project here though..Here it is: http: rapidshare.co...MY_Prj.zip.html[Dear Administrator: The downloading option on the webpage does not allow files bigger than I mb, thts why I used an external link]As I said, in the application, Project A is TMS.NET ; Project B is EncryptFile and Project is C.I encountered a problem while adding project C [spoken word], so the project contains only projects B and A. I will try to attach project C seperately.That is, TMS contains proj A+B and Speech contains C.
