What Are The Various Objects In Dataset
Aug 18, 2010What are the various objects in Dataset ?...
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Synchronize Application Objects With DataSet
Mar 14, 2012I sometimes come across patterns or common practices that I do not agree with. I have a clear opinon of what is considered "good design", which is mainly based on my understanding of abstraction and creating layers.IMO, the core of an application is it's object model. It's a hierarchic model where one object references other objects or lists of them. That's a memory-internal model. For example, a house object references a list of rooms referencing lists of furniture.An object is identified by it's reference. There are no IDs or PKs in that layer.Saving/Loading data is an additional feature. Sure, no application will do without, but it's based on top of the core of the application. I could write an application that works very well without loading/saving, and for version 2 I will think about whether to save data to a database or an XML file. Merely this fact proves that a database layer is not the lowest. I've never agreed with that three-tier model - even if you call me unteachable.
In addition to all application objects, there are Datasets - and that's my problem now. They can be considered as a copy of what is already present in the application's object model. Its from a different, table-oriented view. As both structures exist in parallel, there's the need to synchronize the DataSet with the (rest of the) application's objects.That's the task that I am always struggling with, and I ask how you handle it. I know this is a major design question but, fortunatelly, I could quite get around this problem so far.The only solution I can imagine is maintaining additional relation lists. For example, whenever the property of a room object changes, that change must be reflected in the associated DataRow in the DataSet. For this purpose, I need a look-up table that tells me the PK of the given room in the database. It requires a lot of additional efforst to do all the synchronization.Again, the house or room object itself does not have a PK and it won't get one because on that layer, it doesn't even know that a database exists.
Caching DataSet Objects When Data Changed In SQL?
Oct 5, 2009A quick question on caching dataset objects. How can I know if the data is changed in Sql when caching data? I don't want to specify time constraints but used a strategy where data is changed in sql and I have to refresh my cache?
View 1 RepliesExtension For Dataset Returning List Of Objects
Apr 6, 2010I want to define a function similar to:[code]My current definition is having an issue with the following statement:GetList = (From x In oDS.Tables(0) Select New T(x)).ToList.I can't figure out how to get to create a New object of type T, any suggestions?
View 2 RepliesTake An Array Of Objects And Load It Into A Dataset Datatable?
Oct 16, 2010have a lot of experience with LINQ, but should your verb be attached to the array?
data.Tables("people").LoadDataRow(parsed(int1, 1), True) S/B
data.Tables("people").LoadDataRow(person.parsed(in t1, 1), True)
VB Express 2008 Dataset Not Showing New Database Objects (views)
Mar 3, 2010I am using VB Exopress 2008 and SQl Server Express 2008 in Windows Vista Home Premium. I have created a dataset after importing all tables and queries from MS Access to SQL Server. I have now added a view in SQL Server that I want to access and use in VB Express. However on clicking "Refresh" for the dataset the new view does not display in the available objects, only those I originally imported and opened with the original dataset. What, pleas am I doing wrong? How can I see this new View?
View 3 RepliesMake Objects From The ToolBox Using Code Instead Of Changing Existing Objects Invisible Then Visible Later?
Dec 5, 2011make objects from the ToolBox using code instead of changing existing objects invisible then visible later?
View 7 RepliesSql - Error The SqlParameterCollection Only Accepts Non-null SqlParameter Type Objects, Not Int32 Objects?
Jun 23, 2012I 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].....
Modifying Objects Inside For Each Loop Sets Properties Of All Objects With Values Of Last One?
Jan 29, 2011I have a program like this.
Module Module1
Public Class Mstr
Public Property Prop1 As String
Public Property Prop2 As String[code]....
But it is not working as I expect it to. You can see it from.The DtlsB properties of all three DtlsA objects are having values from last iteration.
Random Objects - Let The User Input Objects To A Richtextbox 1 Object On Each Line?
Jan 6, 2011I 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.
View 9 RepliesThe SqlParameterCollection Only Accepts Non-null SqlParameter Type Objects Not String Objects?
Jan 18, 2012Private 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
[code]....
VS 2008 Inherit ListView - Dispose Of Two Objects When The Form's Disposing Of It's Objects
Feb 7, 2010I 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?
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Child Objects Raising Events In Parent Objects?
May 1, 2009long 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.
ASP.NET Cast ArrayList Of Objects To Custom Objects?
Aug 9, 2011getting the following error Unable to cast object of type 'System.Object[]' to type 'OrderService.webdirect_WebLinesRow[]'. On the line
webdirect(web_companyID, web_locationCode, web_customerNumber, web_orderNumber, web_orderReference, web_orderDate, webLinesArray.ToArray(), o_Company, o_LocationCode, o_CustomerNumber, o_OrderNumber, o_OrderStatus, o_OrdDescrip, webRespArray)
I created the webLinesArray.ToArray() array as such
Dim webLinesArray As New ArrayList()
Am I missing an additional cast or something ?
Compare Two Objects To Check If All The Properites Of Both The Objects Have Same Value Or Not?
Aug 28, 2008I want to compare two objects to check if all the properites of both the object have same value or not. for this i need to use the reflection to enumarate through all the properties of an object and check the value of the property. To try the code just i have written a Employee Class having Two Properties EmployeeNo and EmployeeName. I am creating an object of the Employee class and need to write a function that can list the values of all the properties in the class.
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Bind Objects With Nested Objects?
Jul 21, 2009I am tring to bind a class to a form where the class contains other class variables. For example:
Class Character
Private _name as String
Property Name as String
[code]......
Array Of Child Objects In Nested Classes And Accessing Child Objects In .Net
Jan 3, 2012I have a nested class, let's call it class1 and it has class2 inside it; VB.Net eg:[code]
1) How can I define X number of Class2 objects[let's call it: Node(x) array]** with NEW() subroutine called?' this raises error: dim cls2(n) as new class2 end sub.
2) How can I return actual number of Node() array? [code]Outside my class in main project I define cls1 object:[code]Now an array of class2 is created inside cls1.
3) Now,How can I access All of them[node(x) array which is created inside cls1] with all properties and methods available?
I remember I wrote a ProcessManager class with this functionality in .net 2003, nearly 4 years age, I don't have the code now.
DataSet Editor - Allows The User To Edit A DataTable In A Strongly-typed DataSet
Mar 15, 2010When the user clicks an "Edit" button on my form, I want a box to come up which allows the user to edit a DataTable in a strongly-typed DataSet. What's the best way to do this?
View 2 RepliesIDE :: Dataset Code Behind Datatable.ColumnChanging Event Firing / But Dataset.HasChanges Property Not True
Jan 28, 2010I have code running in the Datatable.ColumnChanging event in my dataset. This dataset underlies a form and conventional drag/drop controls are in place for data entry.when the event triggers and runs, I am running code in the form that checks the dataset.HasChanges property. It is showing False. But this is immediately after the ColumnChanging event has been triggered.Okay, I see by others posts and MSDN that .HasChanges will only be true after moving off the row with the changed column. I have also noted lots of discussion about the advanced binding property of DataSourceUpdate Mode, but that does not address this issue.I guess I can do this by checking the state of the row for the binding source. Just seems odd that the event behind the dataset can be triggered and that does not change the dataset.HasChanges property.
View 3 RepliesSystem.Data.Common.DbDataAdapter.Fill(DataSet DataSet)
May 14, 2012I have tried everything I can to get beyond this error which shows below as <<<<< error here. It is trying to fill a dataset from a data adapter. If I change the SELECT statement to just SELECT * FROM xTable I get the correct number of records in each table. But anytime I try with a more complex statement I get the error message shown below which indicates System.Data.Common.DbDataAdapter.Fill(DataSet dataSet. I've completely erased all data and entered a new set of test data so I know there is no problem with relationships. Each table has primary key which is foreign key in other table. IS there something wrong with the Imports section: Imports System
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.net - Copy Data From Dataset To A Type Dataset Using Automapper?
Aug 24, 2010i am trying to copy data from a standard Dataset to a Type Dataset (XSD) of same table structure. i want to use Automapper to do that one. So how can i do that using automapper?
View 1 RepliesFill A DataSet On Application Startup And Use Dataset Other Form?
Jun 5, 2010I need to pick all data in my application from my database and use it in my form
my question : how to pick all data in my application then i use it
Loop Through Dataset Updating Data From Results Of Another Dataset
Jun 22, 2010I have two Datagrids, One grid has all the customers garments on it with style number and contact length. The other grid has the users who have garment issued to them. the style number is in both grids. I need to loop through the users grid and say if the contract number is 1 from the first grid then the contract date on the second grid will be todays date + 365 days (year contract) I have looked at using a stored procedure and also a for each command but I am just getting stuck with it all. [Code]
View 1 RepliesSaving Dataset To Database Which Has Imported Rows From Another Dataset
Jan 4, 2011I have a problem saving a dataset which contains rows that i have imported from another dataset. i can successfully view the imported rows in a gridview but i cannot commit the rows back to the database.
View 2 RepliesMultithreading - Create Custom Objects/list Of Custom Objects In .NET?
Jan 24, 2010I need two seperate lists, which every item is Integer, String, Bitmap - and one which every item is Integer, String String. However I don't know how to do this, or even where to look - I've googled for custom objects and custom object lists. What I'm trying to do is this.Custom Object1 is Integer, String, Bitmap Custom Object2 is Integer, String, String
In one thread I'll be adding items to List1(Of Object1), and processing them, and adding the results to List2(Of Object2), however I need to be able from other threads to look at the list and say only give me the items where Integer = (my thread ID), is this possible? Any help, or even links to information that would be relevant to this request would be helpful?
.net - Combine Multiple Dataset Columns To One Dataset?
May 19, 2010I have multiple datasets that I would like to combine into one. There is a common ID field that can be associated to each row. Calling Merge on the dataset will add additional rows to the dataset, but I would like to combine the additional columns. There are too many fields to do this in one query and therefore would make it unmanageable. Each individual query would be able to handle ordering to ensure the data is placed in the correct row.
For Example lets say I have two queries resulting in two datasets:
SELECT ID, colA, colB
SELECT colC, colD
The resulting dataset would look like
ID colA colB colC colD
1 a b c d
2 e f g h
Repointing A Report Dataset To A Test Dataset
Feb 18, 2011ok, I've finally got my test database issues sorted out, however now I need to actually modify my existing report to add the two new fields from my test database. I have made a copy of the report so that I am not modifying the original. I have deleted the two old fields and now want to add my two new fields in there. In the Field explorer window, I see an object called "dataset1" and when I expand it, it is using a view that includes fields from the table that I added my two new fields to.
The problem I see here is that I have gone in and modified the view to include these two new fields in my test database - but again, they are not showing up as selectable fields here. I am just assuming that "dataset1" is somehow pointing to the live database again and that I need to change the datasource location.In my solution explorer, I see an object called "dataset1.xsd" but the properties of that do not tell me much about where it is actually pointing to...
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VS 2005 Typed Dataset Vs UnTyped Dataset
Nov 25, 2009I want to access data using both the datasets.
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Try
[Code]....
In my code i have dataset name ds and table named Info1,when i write ds after that how tablename is coming,its not possible? How to do that ?
Can Objects In Objects Be Persistent
Dec 15, 2009[Code] I want that once I put something in the BigCollection it stays there, I don't want it to be changeable from outside. I want to be able to clear the SmallCollection but it should not be cleared in the BigCollection. Any Ideas?
View 1 RepliesCasting Objects To Other Objects?
Feb 6, 2012Firstly I need somebody to explain a bit of code to me, I'm a massive newbie at programming so I need an in depth explanation.
Private Sub Box_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
Dim C As PictureBox = CType(sender, PictureBox)
[code].....