Element Operators Method-Based Query Syntax Examples (LINQ to DataSet)
The examples in this topic demonstrate how to use the First method to get DataRow elements from a DataSet using the method query syntax.
The FillDataSet method used in these examples is specified in Loading Data Into a DataSet.
The examples in this topic use the Contact, Address, Product, SalesOrderHeader, and SalesOrderDetail tables in the AdventureWorks sample database.
The examples in this topic use the using/Imports statements found in Method-Based Query Examples (LINQ to DataSet).
For more information, see How to: Create a LINQ to DataSet Project In Visual Studio.
First
Example
This example uses the First method to find the first e-mail address that starts with 'caroline'.
' Fill the DataSet.
Dim ds As New DataSet()
ds.Locale = CultureInfo.InvariantCulture
' See the FillDataSet method in the Loading Data Into a DataSet topic.
FillDataSet(ds)
Dim contacts As DataTable = ds.Tables("Contact")
Dim startsWith As DataRow = contacts.AsEnumerable(). _
First(Function(contact) contact.Field(Of String) _
("EmailAddress").StartsWith("caroline"))
Console.WriteLine("An email address starting with 'caroline': {0}", _
startsWith.Field(Of String)("EmailAddress"))
// Fill the DataSet.
DataSet ds = new DataSet();
ds.Locale = CultureInfo.InvariantCulture;
FillDataSet(ds);
DataTable contacts = ds.Tables["Contact"];
DataRow startsWith = contacts.AsEnumerable().
First(contact => contact.Field<string>("EmailAddress").StartsWith("caroline"));
Console.WriteLine("An email address starting with 'caroline': {0}",
startsWith.Field<string>("EmailAddress"));
See Also
Concepts
Standard Query Operators Overview