初始化表達式會初始化新的物件。 支援大部分初始化表達式，包括大部分新的 C# 3.0 和 Visual Basic 9.0 初始化運算式。 下列類型可由 LINQ to Entities 查詢初始化並傳回：
零個或多個具型別實體物件的集合，或概念模型中定義之複雜類型的投影。
Entity Framework 支援的 CLR 類型。
以內嵌方式呈現的集合。
匿名類型。
匿名型別初始化會顯示在查詢表示式語法的下列範例中：
Decimal totalDue = 200;
using (AdventureWorksEntities context = new AdventureWorksEntities())
{
var salesInfo =
from s in context.SalesOrderHeaders
where s.TotalDue >= totalDue
select new { s.SalesOrderNumber, s.TotalDue };
Console.WriteLine("Sales order numbers:");
foreach (var sale in salesInfo)
{
Console.WriteLine("Order number: " + sale.SalesOrderNumber);
Console.WriteLine("Total due: " + sale.TotalDue);
Console.WriteLine("");
}
}
Dim totalDue = 200
Using context As New AdventureWorksEntities()
Dim salesInfo = _
From s In context.SalesOrderHeaders _
Where s.TotalDue >= totalDue _
Select New With {s.SalesOrderNumber, s.TotalDue}
Console.WriteLine("Sales order numbers:")
For Each sale In salesInfo
Console.WriteLine("Order number: " & sale.SalesOrderNumber)
Console.WriteLine("Total due: " & sale.TotalDue)
Console.WriteLine("")
Next
End Using
下列以方法為基礎的查詢語法範例會顯示匿名型別初始化：
Decimal totalDue = 200;
using (AdventureWorksEntities context = new AdventureWorksEntities())
{
var salesInfo =
context.SalesOrderHeaders
.Where(s => s.TotalDue >= totalDue)
.Select(s => new { s.SalesOrderNumber, s.TotalDue });
Console.WriteLine("Sales order numbers:");
foreach (var sale in salesInfo)
{
Console.WriteLine("Order number: " + sale.SalesOrderNumber);
Console.WriteLine("Total due: " + sale.TotalDue);
Console.WriteLine("");
}
}
Dim totalDue = 200
Using context As New AdventureWorksEntities()
Dim salesInfo = _
context.SalesOrderHeaders _
.Where(Function(s) s.TotalDue >= totalDue) _
.Select(Function(s) New With {s.SalesOrderNumber, s.TotalDue})
Console.WriteLine("Sales order numbers:")
For Each sale In salesInfo
Console.WriteLine("Order number: " & sale.SalesOrderNumber)
Console.WriteLine("Total due: " & sale.TotalDue)
Console.WriteLine("")
Next
End Using
也支援使用者定義的類別初始化。 支援 C# 3.0 和 Visual Basic 9.0 初始化模式，並假設屬性 getter 和 setter 是對稱的。 查詢表示式語法中的下列範例顯示查詢中正在初始化的自定義類別：
class MyOrder { public string SalesOrderNumber; public DateTime? ShipDate; }
Class MyOrder
Public SalesOrderNumber As String
Public ShipDate As DateTime?
End Class
Decimal totalDue = 200;
using (AdventureWorksEntities context = new AdventureWorksEntities())
{
IQueryable<MyOrder> salesInfo =
from s in context.SalesOrderHeaders
where s.TotalDue >= totalDue
select new MyOrder
{
SalesOrderNumber = s.SalesOrderNumber,
ShipDate = s.ShipDate
};
Console.WriteLine("Sales order info:");
foreach (MyOrder order in salesInfo)
{
Console.WriteLine("Order number: " + order.SalesOrderNumber);
Console.WriteLine("Ship date: " + order.ShipDate);
Console.WriteLine("");
}
}
Dim totalDue = 200
Using context As New AdventureWorksEntities()
Dim salesInfo = _
From s In context.SalesOrderHeaders _
Where s.TotalDue >= totalDue _
Select New MyOrder With _
{ _
.SalesOrderNumber = s.SalesOrderNumber, _
.ShipDate = s.ShipDate _
}
Console.WriteLine("Sales order info:")
For Each order As MyOrder In salesInfo
Console.WriteLine("Order number: " & order.SalesOrderNumber)
Console.WriteLine("Ship date: " & order.ShipDate)
Console.WriteLine("")
Next
End Using
下列以方法為基礎的查詢語法範例顯示正在查詢中初始化的自定義類別：
Decimal totalDue = 200;
using (AdventureWorksEntities context = new AdventureWorksEntities())
{
IQueryable<MyOrder> salesInfo =
context.SalesOrderHeaders
.Where(s => s.TotalDue >= totalDue)
.Select(s => new MyOrder
{
SalesOrderNumber = s.SalesOrderNumber,
ShipDate = s.ShipDate
});
Console.WriteLine("Sales order info:");
foreach (MyOrder order in salesInfo)
{
Console.WriteLine("Order number: " + order.SalesOrderNumber);
Console.WriteLine("Ship date: " + order.ShipDate);
Console.WriteLine("");
}
}
Dim totalDue = 200
Using context As New AdventureWorksEntities()
Dim salesInfo As IQueryable(Of MyOrder) = _
context.SalesOrderHeaders _
.Where(Function(s) s.TotalDue >= totalDue) _
.Select(Function(s) New MyOrder With _
{ _
.SalesOrderNumber = s.SalesOrderNumber, _
.ShipDate = s.ShipDate _
})
Console.WriteLine("Sales order info:")
For Each order As MyOrder In salesInfo
Console.WriteLine("Order number: " & order.SalesOrderNumber)
Console.WriteLine("Ship date: " & order.ShipDate)
Console.WriteLine("")
Next
End Using