How to keep custom paging for dynamic result sets ? (i.e) based on 10 Dropdowns selection my stored procedure will Dynamically generates resultset,but it populates million records.
Row statically know Record count,cusom paging is efficient,but how to achieve it for dynamically grown result set?
Problem
I have to bind generic List to GridView,Columns are fixed,but the number of rows retuened are unknown,but without custom paging my GridView took 30 minutes to populate the result.
If possible, you should use LINQ, as the extensible operations make for easy paging.
Essentially, you would specify an ObjectDataSource or LinqDataSource for your GridView.
You would then have an IQueryable<T> method which accepts a starting position and number of rows to retrieve.
Then you make use of Skip() and Take() to achieve simple paging.
Here's a very good article on doing that.
Remember that Skip() and Take() are methods exposed to any class which implements IEnumerable. So even though the above article uses LINQ-SQL for their data repository, as long as your own DAL exposes a collection of type IEnumerable, you can use the Skip and Take pattern.
Hope that helps.
An easy way to do this server side would be to use LINQ. Took at the .Take() method.
Related
I am trying to rewrite some form to the lisp page template. In a list page you must use query as a datasource. I have datasource structure in previous (without list page template) and a new one with list page template. But I am now facing a fact that handling datasource in form is different than handling it in a query.
Can someone explayin why it is done this way and how to make a query so there will be almost no difference between datasource before and after using list page template?
For example I have DSs Object, Sub-Object1, Sub-Object2.
Sub-Object1 have a jointSource Object in properties with exist joint and Sub-Object1 have jointSource Object with Inner Join.
Is there some way to set this in Query DS properties or I must add
datasource to datasource and link in more manually.
Well mayby because a form need more information than query?
If you do have a query already.you can drag it to your form as a datasource.
See http://msdn.microsoft.com/en-us/library/gg844014.aspx
The same effect as a datasource with join type in properties can be done on query by using related datasources. So on the query the structure will be more readable than structure on normal form datasources.
I have an Stored Procedure which may return some unpredictable rows and columns, based on some business logic written in my SP. That is for sure that it will return only one set of Result Set data from this SP.
Whatever the result my SP returns, it should be reflected into my GridView. Due to some framework restrictions, I can not use ADO.Net DataSets/DataTables.
I am using Entity Framework 4.0 for my project and I want some solution to bind my GridView with dynamic nature of DataSource returned by my Stored procedure.
I think, this is very common problem which many developer has encountered in such type of situation.
Is there anyone who have found some work around to achieve the goal within the boundary line of Entity Framework?
Note: Keep in mind that, I don't want to use ADO.net DataSet or DataTable.
I think you are fetching data from proc and stored in List like that.
List<HRDocumentCheckList> searchJoiningDoc = GetJoiningDocumentForEdit(ddlCategory.SelectedValue.ToInt32(), false).ToList();
gvJoiningDocumentTemplate.DataSource = searchJoiningDoc;
gvJoiningDocumentTemplate.DataBind();
Just bind the gridview and set the autogenrated column is false
Hope it will helps you
Can anyone please tel me an example for how to bind the data with the Collections and Lists. I know how to bind the data with databound controls. But, binding with the collection and Lists sounds little bit tougher.
Thanks.
Regards,
Naren.
You can use Collection.Add or Collection.AddRange where Collection can be any of collection like ArrayList in your case to add your data to the collection.
There is no binding involved here.
Binding is done in between data and controls.
Collections are used for collecting the data and no binding is involved.
I need help choosing between Telerik RadGrid and DevExpress ASPxGridView for Asp.Net based on unique filtering requirements. The data lives in denormalized Vax files. All data access is via Sql Server stored procedures calling ODBC Connx queries to the flat files. Stored procedure parameters are used to filter the data. Without any filter thousand of records are returned.
I've successfully displayed all records on two test ASP.net pages, one with DevExpress ASPxGridVIew and the other with Telerik's RadGrid. In code I databind each grid to the stored procedure that returns over 26,000 rows. The sproc is called via an Entity Framework function import that fills an IEnumerable<Customer> which becomes the datasource of each respective grid. I'm able to use the filter features of both grids and they seem to work nicely.
My problem is that before the grid filter is applied all of the thousands of rows are returned from the stored procedure. I'd like to intercept the grid's filter parameters and apply them to my stored procedure parameters. That way far fewer records will be accessed.
Can this be done with either 3rd party grid and if so how?
Thanks in advance.
It seems it can be achieved using a RadFilter to the RadGrid. One example here.
But in general, looks like you'd need to add a handler to ItemCommand, and perform the appropriate filter based on the CommandName, for example. You could then just rebind the data.
The Rad Filter will also allow you to use it without being directly tied to another control or datasource. The filter has an option to extract a filter expression in many different forms (linq provider is one of them). You can then apply that expression to your datasource. We are doing something similar. We have a page where we dynamically create the rad filter with the types of fields and filter options. The user then uses the rad filter UI to create the filter based on the desired fields, then we extract a filter expression we can apply to a datatable that is created on the page that shows the data.
Here is the code for extracting the filter expression from the filter:
var provider = new RadFilterSqlQueryProvider();
provider.ProcessGroup(myRadFilter.RootGroup);
var sqlFilterExpression = provider.Result;
Often I need to combine data from multiple tables and display the result in a GridView control.
I can write a Linq query inline in the Page_load event, return an anonymous type that combines all the fields that I need, and databind the result to the GridView control.
Problem: I use 'helper methods' as described by Scott Guthrie on his blog. Such a helper method cannot return an anonymous type. The query would have to be inline for this approach.
I can write a database view that returns the data that I need, and write a helper method with a query against this (new and known) type that it returns.
Problem: I will need a lot of views in my database schema, and I will introduce a lot of redundant aspects of my data. I also lose some of the advantage of using Linq - removing all business logic from the database.
I would like to take an approach that lets me keep the Linq queries in helper methods, yet allows me to access all the attributes that I need on the grid in their respective databinding expressions. Can this be done?
I asked the wrong question, as I frequently do. What prompted me to look into anonymous types was an apparent limitation of the GridView - my inability to use a databinding expression in an <asp:BoundField> (the DataField parameter only accepts column names of the table that the Linq query pulls in).
Turns out that in a TemplateField it is possible to use Eval and access members of the Linq data item, and Linq takes care of the query for me.
In other words, I can keep the query in my helper method, have it return a primary database table type (e.g. Account), and I bind the Accounts to the GridView.
In the databinding expressions I can access data members of the Account objects that reside in other tables, without having to explicitly pull them in in the query. Perfect.
I don't know if there is a viable way to achieve this using anonymous types. But I have a suggestion that will work in WinForms, but I am not sure about ASP.NET.
What you need is a type with properties where neither the number of properties, nor the types and names of the properties are known at compile time. One way to create such a thing is ICustomTypeDescriptor.
You have to create a type implementing this interface with an private backing store of objects backing the properties returned by the query for one row from the query. Then you implement GetProperties() to return one PropertyDescriptor per column and PropertyDescriptor.GetValue() and PropertyDescriptor.SetValue() to access the backing array.
By implementing PropertyDescriptor.Name you will get the correct column name; this will probably require another backing store storing the property names. And there is a lot more to implement, but in the end your new type will behave almost like a normal type - and now the if - if the control you are binding to knows about and uses ICustomTypeDescriptor.
UPDATE
I just found an bit of text stating that ASP.NET data binding knows and uses ICustomTypeDescriptor.
Scott's earlier post in the series talks about shaping the result set before inserting into a grid:
Part 3 - Querying our Database
Scroll down to "Shaping our Query Results".