I have recently built an N-Tier app using VB.Net 2008. The application is based on Beth Massi's tutorial at [URL] I am trying to incorporate a datagrridview control on a Parent form - one parent (father and mother) to many children. For example,
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I am going to ask a dumb question. I want to update my tables (two). There is a one to many relation between them. I know how to update when only one table is update, but how do i update when there is many on the other side. My problem is that , if one of the records on the many should become redundant, how would i delete it in the update process. If only the content changes , it is not a problem, i know the data just gets written back to the tables, but if one of the child records is not delete, how would it work I need some clue on the SQL statement using OLEDB
View 2 RepliesI'm trying to create a document that displays a list of items, with details below each item. I feel like what I'm trying to do should be relatively simple, and the answer is hiding under my nose, but I can't find what I'm looking for.
For an example, let's say I'm just listing people, with a child list of their favorite foods.
This is how the data will eventually be displayed:
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I'm trying to do this with a gridview control. I'm not sure that's what I should be using. But what I'm having trouble with, is getting the gridview to only list items with a unique USERID. And then using that unique USERID to list each item individually below.
Is there any kind of "automated" way of pulling this off using standard .net controls without going in and manually piecing it all together from the codebehind?
I am developing a small windows application(vb.net).In that i want to have parent child relations in a gridview control. There are lots of examples available on this, but they are using two gridviews for that, but in my case i want the relation to be displayed in a single gridview control itself. When they click the + sign immediate row should populate child rows with it's own header(ie child rows has it's own header which is different from parent header). In my case parent row has 2 columns and child row has 4 columns.
View 2 RepliesThe database strutcure is:
Id Name ParentId
1 File NULL
2 Open 1
3 Save 1
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I am using the database PostgreSQL.
I want to program a water supply pipeline network in a treeview control. It has five node (junctions). The parent-child relation is based on a parameter (say pressure). Initially, the node 1 is parent and its child nodes are 2 and 3. The node 3 has child nodes 4 and 5. At run time the pressure changes. Now, node 3 is parent and its child nodes are 1, 4 and 5. The node 1 has child node 2.
View 7 RepliesI have a situation where a database table is updated with records inside a loop. Every record in this table has a parent child relationship with another table. This child table is also updated subsequently inside the same loop.I am creating the datatable for Parent table and adding records inside the loop, but committing the records in the database (using SqlCommandBuilder) outside the loop only once.
Inside the loop I am also calling the function for updating records in the child table. Because the adaptor and datable objects are created inside the child table function, I need to commit records in child table inside the function only. So this happens before commit of parent table. Because there is a PK-FK constraint in the database, an error is generated.
Simplest solution would be to bring all code inside one function. But I don't want to do that. Besides this parent child relations can go upto any levels.
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I have a large application that has always existed all in a single .NET project up until recently (200,000+ LOC). I'm finally getting to the point where I can fix this. I just started using the Entity Framework (4.1 using code first) and I believe this is a good time to start seperating my logic.
What I did is I separated my application into three subprojects:UI - Windows forms project Business - The POCO classes Data - Legacy data access code AND the DBContext class to connect my POCO classes to the database. I also have a Windows service project and will soon have a WCF project, but those concern me less.
The problem is that in this plan, the data layer depends on the business layer and vice versa causing a circular reference error. There is no way around this.So, my idea is to move my POCO classes into the data layer removing all business logic first (just keeping the database fields, basically). Then, I will inherit from those classes in the business layer adding back all the business rules. Then my data access layer will not rely on any other project, the business layer will rely just on the data access layer, and the interface layer will rely on both for now but eventually only on the business layer.
Does anyone see any problems with this, or a better way of doing things given my current circumstances?
Using VB.NET 2008 I want to know what is 3 Tier Architecture for windows application? How to make a code for Inserting, Deleting, Updating in a database using 3 tier architecture.
View 5 RepliesBuilding a large application using 3 tier architecture in vb.net. Question: I am a vb.net developer. I have developed small and medium size application with 2 tier architecture. Now I am going to develop a large application. I have decided to develop that application using 3 tier architecture. So I studied about 3 tier. Now I know how what is 3 tier and how to develop a simple application. And also I studied about .Net Remoting and Web services. In my project, 7 modules are available. Each module has 3 layers. How can I manage in a Single Solution?
View 1 RepliesIn my DataGridView table i have one column called "Category".In this "Category" column values are like
3101,
3102,
3103,
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In my WPF Form1 I have TextBlock1 that fill from AddressTableAdapter. To edit address user must click EditButton to open Form2 to perform changes. My problem is passing data to Form2 from Form1. In Form2 I have 3 TextBoxes Street, City, Zip, and StateComboBox. I try to code in Loaded procedure of Form2 like this and got error message:
Private Sub Form2Detail_Loaded(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles Me.Loaded
Me.AddressTableAdapter.Fill(Me.AbcDataSet.Address)
Me.StreetTextBox = IIf(IsDBNull(AbcDataSet.Address.StreetColumn), "", AbcDataSet.Address.StreetColumn))
Me.StateComboBox = IIf(IsDBNull(AbcDataSet.Address.StateColumn), 0, AbcDataSet.Address.StateColumn))
End Sub
I have a main form, and some sub forms, and each sub form can have some sub forms. When I have multiple sub forms open, and I try to get data from the parent form, it returns the data from the wrong parent form.For example I have two instances of Mainform.subform running. If I do something like this in a child form of one instance of the subform. It returns data from the other subform.
dim l = Mainform.subform.listofdata
Edit:I am using visual Studio 2008. Winforms, form designed using designer. In my mainform I am doing this
Protected Friend frmMain as Mainform
frmmain = new mainform
In frmMain I am doing this
Protected Friend frmsub as new Subform'
frmsub = new subform
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i have three forms
when i click button1 on form1=====> form2.showdialog()
then click button 1 on form2 =====> form3.showdialog
then click button 1 on form 3 =====>
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I'm trying to pass a variable from a child form that contains a DataGridView, I'm calling a function to do the action, but I can not succeed alone function gets the value but does not alter the form's datagridview father, the code I'm using is:
Invoice_new (Parent FORM):
Controls:
DatagridView: invoice_items
Public WriteOnly Property ValueFromChild() As String
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I have two forms....Mainform is filled with controls that are databound to a datasource.....then I have a child form that is used to edit data from parent form.......the data that is displayed on the child form uses the Filter() method of the binding source to display data only for the customer selected......
The child form has the standard OK and CANCEL buttons set up as dialog result.......after I edit the content in child form, the changes are displayed on the child form correctly......but when closing the child form and going back to the parent form the changes dont appear there unless I restart the application.....I also tried adding the tableadapter.update/fill method in the 'OK' dialog result event handler and it still doesnt work......
How can I make the changes take effect on the parent form without restarting the application?
Im working with MDI parent/child objects. when closing the child objects i need the child to check to see if it is the last child object before closing. i couldn't find anything on google, maybe im searching for the wrong thing.
View 2 RepliesI've made a ContextMenuStrip to use in my program to change the image in a picture box. However, it's used with multiple picture boxes which each need to have their own changed. What I want to do is make my command change only that picture box leaving the others as they were before. An example, if this were a plausible code.
Private Sub TestToolStripMenuItem_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles TestToolStripMenuItem.Click
Self(aka the control that currently has the menu open).Image = My.Resources.Picture
End Sub
I enter the data and save, the problem I having is the data of the parentis saving but the child is not.I've notice when I click add, the parent has focus but the child does
Can I have both the parent and child data file on one form, if I can how do I get both to accept and save data.Also if anyone can suggest a bookon building and understand database for visual studio, especially about relational databases and
I have a little big problem in one application.
I have a datagridview with data from a datatable, this datatable have these fields (id,num1,num2, date,user,ref,qt,cost,center), some of them are hided in the dgv (id,num1,num2,date,user). The user can edit,delete and add new rows to the dgv.
I have a save button that performs this actions:
First check if there are new rows, and if yes it fill the hidden fields. Then validate the inserted values by the user with a couple of ifs. In the end, i call the bindingsource EndEdit, and call the adapter Update command against the datatable...
This sometimes works others not really, i don't understand why.
The error it's: "Concurrency violation: the DeleteCommand affected 0 of the expected 1 records"
I think sometimes when Updating it occurs to.
I am writing an application in VB 2008 Express which will consist of a parent process which calls / runs / executes several child processes. I can happily start up a utility program from the parent process, passing parameters to it through Process.StartInfo.Arguments
View 1 RepliesI'm using vb.net 2008. And I am using ADO Update to Insert new data. So I have a Dataset with two tables - one a Parent and one a Child. When adding new Parent plus some child data on the client side, and then Inserting it into the DB (using TableAdapter.Update), how does the child get the new Parent ID?
View 1 Repliesi have a one two many relationship on a form that loads empty so that the user have to do a search in order to populate the data into the form. To acomplish this, i created a filter (query) in the dataset. The filter works fine for the parent data, but how can i load its corresponding child data?
This is the code generated automatically when i created the filter in the DataSet:
VBCode
Try Me.TblConfidencialesTableAdapter.Buscar_Confidencial(Me.ConfidencialesDataSet.tblConfidenciales, TablillaConfidencialToolStripTextBox.Text)
Catch ex As System.Exception
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I'm experimenting with a plugin architecture for my company's internal business system. I have managed to read all .DLLs in a Plugin folder which implement a specific interface. What I am trying to figure out is the best method of communication between the "host" MDI parent application and forms that will be in the .DLLs which I intend to make MDI children.
Currently, I am returning just ToolStripMenuItem objects from the .DLLs to add to the MDI Parent. I've also tested that events wired in the .DLLs to the ToolStripMenuItems do propagate to the code in the .DLLs. I've also managed to return a Form object via the interface and open that form, as the Plugin folder is being "scanned".
However, I am not clear how I would make these forms MDI children. Also, any other forms living in the .DLLs will also have to be MDI children. I created a VS 2008 Addin project just to see what's going on, and it seems that the Addin accepts an Application object on which it adds to the ToolStripMenuItems and does other operations. The code to build the menu inside the .DLL. This is opposite of what I have done so far, where the MDI requests a ToolStripMenuItem from each .DLL and adds the returned object to its own menu.
Would designing my plugin architecture to accept an application object in the same manner the only way I could get forms to open as an MDI child? Am I asking for other, currently unknown to me, headaches by NOT passing in the application object to the .DLL?
I've been asked by a local window cleaner to design a small utility that can display a grid of customer data, sort them, and then export it out as a formatted .txt or rtf file.
View 14 RepliesInstead of connecting to database,I create datacolumns of two data tables.assign foregin key constraints and primary keys to the columns.Add these datatables to dataset and create relationship between them.Now by using RowFilter property,how to display the child table in a datagrid by clicking on parent record in another datagrid?Accept and Award Points Accept as Solution
View 2 RepliesI am sorry to keep bothering you about this damn DataGridView control ... As you might have noticed I am having a hard time with the DataGridView control ... My latest problem has to do with updating the data base file (Access) through a DataGridView control .
Up to now I have managed to successfully edit an entry in the DataGridView control and moreover to successfully update the data base file itself .
The above form and its code work fine . The problem starts when I am trying to run the code of the Update button from another form .
You see , I have another form , through which I change the contents of some of the cells in the DataGridView control (back in Form1) . What I want next is to simply update the data base file itself , just like I was doing with the button in the first form , after I manually changed the cell in the DataGridView control .Thus , on the second form I have a button with this code :
Form1.Button1_Click(Nothing, Nothing) (of course the Click event is declared public)I have also tried :
Form1.Button1.PerformClick()
but still nothing ...Although Form2 successfully changes the cells back in Form1 , the data base file itself does not get updated ...If I manually press the Update button in Form1 I once again successfully update the data base file , but I want to do the whole thing by calling the Update button from Form2 .
have a form with 3 comboboxes and 3 Bindingdource dropped on, Now I can manage to have the first dropdown box display a list of manufacturers ok then when one is selected to display the range of products made and be able to open a form etc based on that, but what I really want to do is in the 3rd combobox display a list of models of the product in combobox2... Is this possible?. I have spent hours trying to figure this out and looking on the net but all examples only point to 1 parent and 1 child..
View 3 RepliesI have the following code that creates a master/detail scenario between a products table and a test table based on the productid: [code]Unhandled exception has occured. the constraint cannot be enabled as not all values have corresponding parent values as you will see, where I add the datarelation between the two datatables i've added a false. This ensures constraints are not created.That solved the problem. However, I want to know if this is the correct solution. It is really difficult to troubleshoot as I cannot reproduce the error. The database is accessed through the network. it could be the network was down at the time so the child records where not inserted hence the error.
View 4 RepliesHow can i write code to check if the hyperlink that would show the data for the child table has been clicked. When i try to use code such as currentcell.gettype it would simply say datagridcell but does not provide any more information?
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