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Usage of LINQ and Datasets in Compact Framework 3.5

, 14 Jun 2007
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Introduction to working with LINQ and DataSets in Compact Framework 3.5 Beta 1

Screenshot - demo.jpg

Introduction

In this article, I will speak about LINQ and Compact Framework 3.5. I've written a simple example to demonstrate how we can use LINQ and Dataset to manipulate data.

Background

What is LINQ? LINQ is a codename for the set of extensions to the .NET Framework that encompass language-integrated data query, set, and transform operations. It includes extensions to the C# and Visual Basic languages with native language syntax for queries. It also provides class libraries to take advantage of these capabilities. With the release of Compact Framework 3.5 and Visual Studio "Orcas" Beta 1, LINQ extensions are now also available for mobile development.

About the sample

In this example, I will demonstrate a simple application that has one form. It displays and searches countries' information in a grid. For an illustration of how to work with LINQ and Dataset, the application will retrieve data from the SQL Server Compact Edition file demo.sdf. The application uses Typed Data Adapter as the Data Access Layer and DataTable as the data type.

Screenshot - ds.jpg

LINQ in action

In the code below, I am retrieving data from a database and filling in the Countries DataTable. After that, just for illustration, I am using LINQ to sort and display the data in a grid through the bindingSource object.

///Loading data from demo.sdf to Countries table
private void LoadData()
{
    ///Get Data
    Countries = dal.GetData();

    ///Building LINQ Query
    var query = from r in Countries.AsEnumerable()
        orderby r.Field<string>("Name") ascending
        select new 
    { 
        Code = r.Field<string>("Code"), Name = r.Field<string>("Name") 
    };

    ///Binding data
    bindingSource1.DataSource = query;
}

In the code below, I am using LINQ to search data in DataTable.

///Building LINQ Query
var query = from r in Countries.AsEnumerable()
    where r.Field<string>("Name").ToLower().Contains(txtSearch.Text.ToLower())
    orderby r.Field<string>("Name") ascending
    select new 
    { 
        Code = r.Field<string>("Code"), Name = r.Field<string>("Name") 
    };

///Binding data
bindingSource1.DataSource = query;

Conclusion

As you can see, LINQ is very easy and intuitive to use. Its syntax is quite similar to that of SQL and it is a part of the C# and Visual Basic languages. We can use it to manipulate data in many scenarios.

History

  • 14 June, 2007 -- Original version posted

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

About the Author

Oleg Levin
Software Developer SoftSolutions
Israel Israel
No Biography provided

Comments and Discussions

 
GeneralMy vote of 4 Pinmembersuhaslive12-Oct-11 17:10 
QuestionHow about the update dataRow in LINQ? Pinmemberagskid1-Jul-09 17:21 
AnswerRe: How about the update dataRow in LINQ? PinmemberOleg Levin1-Jul-09 18:13 
GeneralRe: How about the update dataRow in LINQ? Pinmemberagskid2-Jul-09 3:19 
AnswerRe: How about the update dataRow in LINQ? PinmemberOleg Levin2-Jul-09 4:41 
GeneralHi there PinmemberSebulba_se10-Sep-08 5:29 
GeneralRe: Hi there PinmemberOleg Levin10-Sep-08 7:00 
QuestionAsEnumerable() does not exist. Pinmemberzhenyulu200317-Aug-07 12:04 
AnswerRe: AsEnumerable() does not exist. PinmemberOleg Levin18-Aug-07 8:37 
GeneralRe: AsEnumerable() does not exist. Pinmemberzhenyulu200320-Aug-07 2:56 
GeneralCompact Framework PinmemberPamela198412-Jul-07 21:38 
GeneralRe: Compact Framework PinmemberOleg Levin13-Jul-07 2:56 
GeneralRe: Compact Framework PinmemberPamela198415-Jul-07 3:17 
GeneralRe: Compact Framework PinmemberOleg Levin15-Jul-07 8:32 
GeneralRe: Compact Framework [modified] PinmemberPamela198417-Jul-07 19:43 
QuestionLINQ Pinmembergagliapas19-Jun-07 13:43 
AnswerRe: LINQ PinmemberOleg Levin19-Jun-07 20:02 
Generalnice PinmemberSacha Barber14-Jun-07 22:37 
GeneralRe: nice PinmemberOleg Levin15-Jun-07 6:14 
GeneralThanks Pinmembermerlin98114-Jun-07 5:21 

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