DataSource Controls :: Using LINQ Datasource Control To SQL Databind
Feb 18, 2010
I have got an issue while using LINQ 2 SQL.
public IEnumerable<Customer> GetCustomers()
{
Table<Customer> custObject = context.Customers;
IEnumerable<Customer> filteredCustList = from customer in custObject
select customer;
filteredCustList;
}
GridView2.DataSource = utilLinqClass.GetCustomers();
GridView2.DataBind();
(no errors at build time or at compile time) Error I am getting is: An attempt to attach an auto-named database for file App_Dataaspnetdb.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
I added a column of type "timestamp" to a table in SQL Server to use for concurrency control. I deleted all my tables from the Linq surface and then added them back. I see that the "Time Stamp" attribute is set to True for the timestamp column and False for all the other columns. I also see that the "Update Check" attribute is set to Never for all columns, including the timestamp column.
After watching some demo videos and reading some tutorials, I had expected to have to manually set the "Update Check" attribute values on the columns - to Never for all columns but the timestamnp column where it should be set to Always. But, before setting the "Update Check" to Always on the timestamp column, I decided to test it the way it was, and Linq seems to be doing the right thing - it seems to be using the timestamp column for concurrency control correctly even with "Update Check" set to Never on the timestamp column.
So my question is - does the fact that "Time Stamp" is set to True trump the "Update Check"? Or is there any other reason one could or should set "Update Check" to Always on a timestamp column? Is there any change in behavior?
I have Gridview control which bind data from LINQ datacontext object which use store procedure. sort the gridview using LINQ datacontext object which use store procedure.
am having trouble figuring this one out. Am using stored procedure and using databind for the gridview . i got the codes off other sites. I'm guessing its the code that i've underlined, how or what do i use as the datasource for the sorting event. I used the Session for the paging event and that works but not for sorting.
Here is the situation I have, I have a repeater inside a Usercontrol. The datasource is a IEnumerable<Investor> Exposed through a UserControl's Property. I have overridden the UserControl's databind event to set the Repeater Datasource before databinding the repeater. When it's not a postback, it databinds find and the events on the repeater item's controls fires up fine. But there is one event on repeater items (Delete Investor) which call back the DataBind of the UserControl after removing the Investor from de datasource. When this Event is called, it does all the work (deleting the investor and so on...) calls back the usercontrol's databind but when (within the usercontrol databind) the repeater is databinded again, the repeater items doesn't update (repeater items for investor not on the DataSource anymore still appears). My ItemDataBind doesn't even fire by then.
[Code]....
and code bedind
[Code]....
I Tried with both the Repeater Item Command and each LinkButton Event to see if it would make any difference, but none worked
I am writing a plugin to help with a current ERP system we have that I am not allowed to modify the data structure at all. The table I am dealing with has over 100 columns and I am wanting to set my linq object propertychanged event and submitchanges or do I really have list out each property and set it equal to the new one?Below is an example of what I am trying to do:
Like that I have large number of controls on my form. I have dought, if I assigned like this, db.usp_ATI_FetchPatientDetails(iPatientID).ElementAt(0).Last_Name.ToString(); to every control, then I have set of controls like,
My question is that, for each control the Stored Procedure called or not? If it is yes then it is time consuming and I need to use LINQ to DataSet or LINQ to Object rather than to call SP for each control. What is difference between LINQ to DataSet and LINQ to Object?
I need to pull a SubString from a Linq Datasource, but can't use INTs per .SubString(int, int) I have strings such as xxxx.xxxx.xxxxx.AAAA.xxxx.xxxx.xxxx.xxx and I need to pull AAAA out. the preceeding x's will be varying lengths, so I can't use a static int. What I do know is that there will be a static number of periods (.) leading up to the AAAA. I can't figure out how to use the SubSting with characters rather than indexs. This is what I have so far:
As you can see, the connectionstring parameter is defined to a specific connection string name and I need to be able to set such a parameter to a different value, for example, to a session variable content.
I've a listview with checkbox control in it and datasource as object data source.
I'm updating the values in listview using update method in object data source, problem is I'm not able to pass the value of checkbox checked in the update event as parameter.
i my website i am using Repeater control which further contain checkboxlist control. Now my problem is that i have successfully bind "Parameter Type" in repeater control but when i am binding checkbox values, it does't appears in display
<asp:Repeater ID="Repeater1" runat="server"> <ItemTemplate> <h4> <%#Container.DataItem%></h4> <asp:CheckBoxList ID="chkParList" runat="server" RepeatDirection="Horizontal" DataTextField = > </asp:CheckBoxList> <br /><br /> </ItemTemplate> <SeparatorTemplate> <hr /> </SeparatorTemplate> </asp:Repeater> In *.cs file following are my code IMonitoringDataInfo objMonitoringDataInfo = new ChannelFactory<IMonitoringDataInfo>("MonitoringDataInfo").CreateChannel(); Collection<ParameterDetailDTO> clParameterDetailDTO = objMonitoringDataInfo.GetAllParameters(idList, out errorCode); var parameters = (from resx in clParameterDetailDTO select resx.ParameterType).Distinct(); Repeater1.DataSource = parameters.ToList(); Repeater1.DataBind(); counter = Repeater1.Items.Count; while (i < counter - 1) { foreach (var parType in parameters) { var items = from resx in clParameterDetailDTO where resx.ParameterType.ToLower().Contains(parType.ToLower()) select new { resx.ParameterName, resx.ParameterID }; ((CheckBoxList)(Repeater1.Items[i].FindControl("chkParList"))).DataSource = items; ((CheckBoxList)(Repeater1.Items[i].FindControl("chkParList"))).DataTextField = "ParameterName"; ((CheckBoxList)(Repeater1.Items[i].FindControl("chkParList"))).DataValueField = "ParameterID"; ((CheckBoxList)(Repeater1.Items[i].FindControl("chkParList"))).DataBind(); } i++; }
I am trying to use a linq query to create a report and I am unclear on how to traverse the linq dataquery in my case. Inside my for each loop, i have a do while loop. The way it is written below, the do while loop is infinite because I never skip to the next itm in oneSchedule. Placing a Next inside the do while loop causes a syntax error. So what is the correct method for moving to the next itm within the loop?????
select * from MyTable select "MonthName"= case when datepart(month,date1) =1 then 'January' when datepart(month,date1) =2 then 'February' end , count(*) as CountByMonth from venkat group by datepart(month,date1)
I'm trying to "move" a LinqDataSource control to code behind to better control the query parameters. Problem I'm having is how does the "It" keyword translate to Linq To SQL syntax (not sure if I'm getting the terminology right here, but I think you get my meaning).
If I have an ID, I would like to retrieve the next item that also has the same category as the item ID I have. So, for example, if I have ID=2, I would like to return the item with ID=4 (as item ID=3 has a different category).
Whenever you want to implement Linq to SQL on a project there is inevitably a battle between the DBA and the developers over it.
From the developer standpoint, Linq to SQL eliminates the need to manually write stored procs, ADO.NET data access classes, business object classes, and datatable -> business object conversion classes. This makes development a breeze and eliminates a lot of the traditional layers that you'd normally have to code.
Alternately, from a DBA perspective there are some issues. One is that a lot of DBA's like to do security at the sproc level, and this level would be gone. Another issue is that if the DBA wanted to mimic some sql functionality that the application is doing, possibly for a scripted action, they wouldn't be able to simply call the sproc that the application is using. Also they wouldn't be able to tell which columns are actively being used and which are not, as it'd be C# code specifying which columns are returned rather than sprocs. Lastly, if something needed to be changed structurally, it'd require a recompile and redeploy of the entire app rather than a simple sql script of 2 being deployed.
There are valid points on both ends, so I'm wondering what experiences you all have with this and what sort of compromises you made. In my situation, I'm the developer and I'm trying to figure out a compromise I can make with the DBA so we both give a little rather than one of us having to completely bend over. The obvious compromise to me is using sprocs from within Linq to SQL, but it adds another layer of development and the sprocs have to coded a certain way to play nice with Linq to SQL.
