ADO.NET :: Update Generic List With Linq?
Dec 8, 2010
I have a class Trans with various properties, including a boolean named Deleted.I have a generic list of Trans that are loaded from the database. I want to use linq to set all the Trans in this list to Deleted. Can I use linq to do this?
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Nov 23, 2010
I have declared a simple class
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And Pass some values to it :
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Then I use Linq to select rows :
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How I can enumerate it?! I used this, but it has error
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Jan 20, 2011
I have implemented a generic repository patteren for performing CRUD operations against a database. Functions Insert/Delete/GetSingle works fine but update method doesn't work whenever database table consist of relationships but for standalone table it works fine.When i try to update a table with relationship i get following error:An attempt has been made to Attach or Add an entity that is not new, perhaps having been loaded from another DataContext. This is not supported.Here is my update method:
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Nov 30, 2010
I have a following generic list method that contains some data for a gridview. I need to supply edit and delete functionality for it.
List<students> List(string id)
{
List<students> st = new List<students>();
[code]...
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Feb 6, 2010
I have the following Students class:
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I need the 1 since it's a foreign key in another table. For the life of me, I can't get this to work like this.
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Jan 3, 2011
I have a list view control. Each row within it has a rowid and a textbox where a note(user enters relevant info to that particular record) is entered. On a paging event I store the rowID and the note text in a generic list for retrieval if the user pages back later on. Goal here is to keep the text the user has entered. (see the code below)This generic list does in fact get populated correctly when I go to the next page currently. I can see this in Visual Studio. So now, when the user goes back to the first page I want to run a test within my Listviews ItemDataBound event. I want to see if the row ID being tested is part of the generic list. If so, I then want to take the corresponding note that is also within the list and bind it to the text box. However, I don't know how to write the correct conditional for this and how to bind the textbox if the conditional evaluates to true.
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Apr 7, 2010
I have two generic list with Hotel class object. Both List contains hotel ID. I want to retrieve common hotel id from both Hotel List and assign to new HotelList.I have done following code for that but any other sort way to implement this kind of functionality.
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Note: I dont want to use Linq because I am working on framwork 2.0
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Aug 4, 2010
I'm trying to render out some images on an aspx page. Error I'm getting in the code below is:
DataBinding: '_Default+ImageThing' does not contain a property with the name 'FileName'.
public class ImageThing
{
public string FileName;
}
private void DisplayThumbnailImages()
{
ImageThing imageThing1 = new ImageThing();
ImageThing imageThing2 = new ImageThing();
imageThing1.FileName = "asdf.jpg";
imageThing2.FileName = "aaa.jpg";
List<ImageThing> imagesToRender = new List<ImageThing>();
imagesToRender.Add(imageThing1);
imagesToRender.Add(imageThing2);
Repeater1.DataSource = imagesToRender;
Repeater1.DataBind();
}
here is the aspx:
<asp:Repeater ID="Repeater1" runat="server">
<ItemTemplate>
<%#DataBinder.Eval(Container.DataItem, "FileName")%>
</ItemTemplate>
</asp:Repeater>
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Jan 19, 2011
in my model there is a List.
public class InvoiceModel{
public int InvoiceID { get; set; }
public int Date { get; set; }[code]...
for create view i can use Html.TextBoxFor(m => m.InvoiceID) and for Date.but how can i fill List?and how can i use global for this list as Shopping cart?
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Nov 16, 2010
I'm having trouble doing a left outer join with multiple generic lists tables. I've been researching for hours and there isn't a whole lot out there on this subject and VB (at least what I found).
I have the following Linq query:
Dim DataForGridview = (From s In S1 _
Join c In C1 On c.ID Equals s.ID _
Join v In V1 On v.ID Equals s.ID _
Select New With { _
.dataFieldID = s.ID, _
.dataField1 = s.dataField1, _
.dataField2 = c.dataField2, _
.dataField3 = c.dataField3, _
.dataField4 = c.dataField4, _
.dataField5 = v.dataField5 _
}).ToList()
S1 has a count of 30. V1 has a count of 20. C1 has a count of 10. This query joins the three but ends up with a count of only 10 based on the datakey ID and, of course, only shows those 10 in the gridview.
I would like to show all 30 from S1 in the gridview with blank fields wherever V1 and C1 do not have data. From what I've read I need to do a left outer join. However, all examples I've found are with two datasets.
I've tried multiple times expanding on what I've found by changing it to a group join and also adding the .DefaultIfEmpty() property in the query, but nothing is working.
How can I change the above query to a left outer join with these multiple tables?
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Aug 17, 2010
Can any one can describe the main diffrence between the array and generic list.
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Apr 7, 2010
I have one Hotel class that contains many properties. When I retrieve all hotels data from database, I store them in Generic List object.Now what I want that I have two properties called LowestPrice and HiestPrice. I want to get Minimum(LowestPrice) and Maximum(HiestPrice) from generic list directly.
Something like HotelList.Min();
Right now I have following logic implemented in my project, but I dont want to use foreach loop.
[Code]....
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Aug 1, 2010
I have a list of Categories which I need to bind to a TreeView control in WPF and I can't find a working tutorial or get it working.My Category class consist of (ID, Title, ParentID). If the Category is a top level category the parentID is null.Can anyone sow me how to bind this to a treeview?
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Jun 25, 2010
I am using datalist to bind the generic list. On databind() command I am getting error "nable to evaluate expression because the code is optimized or a native frame is on top of the call stack.
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Feb 22, 2011
I am trying to bind generic list to DropDownList an i am not sure how to continue.
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Aug 31, 2010
I am working in asp.net 3.5 page, where I want to bind a textbox with generic list data. And I have Previous & next button. Which will show the record in textbox.
I don't want to go in db again and again.
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May 25, 2010
i have these values in my generic list:
Product Name ItemCount Additional Info
Brioche & Jam 2
Almond Croissant 4
Mixed Salad(v) 20 No Onions
Mixed Salad(v) 5
What i am trying to do is group the duplicates so now the list would look like this:
Product Name ItemCount Additional Info
Brioche & Jam 2
Almond Croissant 4
Mixed Salad(v) 25 No onions
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Sep 20, 2010
I have a GenericList and i want to convert that to DataTable My code is here
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I am getting Count in "objFinOpRegs". But i want to convert "objFinOpRegs " to DataTable.
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Sep 14, 2010
Here is what is in my code-behind:
List<Event> events = new List<Event>();
protected void Page_Load(object sender, EventArgs e)
{
}
protected void AddEvent_Click(object sender, EventArgs e)
{
Event ev = new Event();
ev.Name = txtName.Text;
events.Add(ev);
}
I want to add an item to the list every time the Add button is clicked, but the list is reset after every postback. How can I keep the data in the list between postbacks?
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Aug 19, 2010
How to use Generic collection and generic list effectively in a asp.net application i.e. web application.? Can we able to use Generic list in Dataset or Datatable or Datareader using to bind in Grid view?
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Feb 9, 2010
I have a generic list which contains a class called Parameter. Parameter contains 2 integers, ParamType and ParamValue. A generic list is built containing a small number of values List<Parameter> myList I have created a function which passes in 2 parameters. These are passed individually but are used to create a new Parameter within the function. The Parameter is tested against myList, and if it is found removed. In order to do this I have used the remove function, the syntax being:
myList.Remove(new Parameter(ParamType, ParamValue));
The remove isn't working and at present I'm using LINQ to do it.
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Dec 29, 2010
I notice that my generic list is maintaining only one item, i declared it in the aspx.cs page f one of my forms. I am assuming that each time the page is reloaded when I add an item the list is redeclared. How can I stop that?
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Apr 1, 2010
I'm trying to use a Generic list for my class but I'm getting this error "Conversion from type 'EnumerableQuery(Of VB$AnonymousType_105(Of String))' to type 'String' is not valid."
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-imperialx
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Jan 22, 2010
I am trying to bind the gererist list type to GridView control but for some reason its just displaying "Member"(Object name) rather then the actuakl content inside object.Any Idea why?Below i have decleared a List Type Member:
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And the Below trying to bind with gridview:
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Feb 26, 2010
I've got a class that implements IListSource and returns a generic List of ListItem objects (List<ListItem>). in this list one of the ListItems has the Selected attribute set to true.On the web page I have a standard asp:dropdownlist and I set it's datasource to the getList method of my class and databind it.The problem is that the databind seems to loose the selected Item and the first item in the generic list becomes selected.
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