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Sign inDataLoadOptions.AssociateWith Method
Definition
Important
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Overloads
| AssociateWith(LambdaExpression) |
Filters the objects retrieved for a particular relationship. |
| AssociateWith<T>(Expression<Func<T,Object>>) |
Filters objects retrieved for a particular relationship. |
Filters the objects retrieved for a particular relationship.
public:
void AssociateWith(System::Linq::Expressions::LambdaExpression ^ expression);public void AssociateWith(System.Linq.Expressions.LambdaExpression expression);member this.AssociateWith : System.Linq.Expressions.LambdaExpression -> unitPublic Sub AssociateWith (expression As LambdaExpression)Parameters
- expression
- LambdaExpression
Identifies the query to be used on a particular one-to-many field or property. Note the following:
If the expression does not start with a field or property that represents a one-to-many relationship, an exception is thrown.
If an operator other than a valid operator appears in the expression, an exception is thrown. Valid operators are as follows:
Where
OrderBy
ThenBy
OrderByDescending
ThenByDescending
Take
Examples
Northwnd db = new Northwnd(@"c:\northwnd.mdf");
DataLoadOptions dlo = new DataLoadOptions();
dlo.AssociateWith<Customer>(c => c.Orders.Where(p => p.ShippedDate != DateTime.Today));
db.LoadOptions = dlo;
var custOrderQuery =
from cust in db.Customers
where cust.City == "London"
select cust;
foreach (Customer custObj in custOrderQuery)
{
Console.WriteLine(custObj.CustomerID);
foreach (Order ord in custObj.Orders)
{
Console.WriteLine("\t {0}",ord.OrderDate);
}
}
Dim db As New Northwnd("c:\northwnd.mdf")
Dim dlo As DataLoadOptions = New DataLoadOptions()
dlo.AssociateWith(Of Customer)(Function(c As Customer) _
c.Orders.Where(Function(p) p.ShippedDate <> DateTime.Today))
db.LoadOptions = dlo
Dim custOrderQuery = _
From cust In db.Customers _
Where cust.City = "London" _
Select cust
For Each custObj In custOrderQuery
Console.WriteLine(custObj.CustomerID)
For Each ord In custObj.Orders
Console.WriteLine("{0}{1}", vbTab, ord.OrderDate)
Next
Next
Remarks
In the following example, the inner loop iterates only over those Orders that have not been shipped today.
Applies to
.NET Framework 4.8.1 and other versions
| Product | Versions |
|---|---|
| .NET Framework | 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
Filters objects retrieved for a particular relationship.
public:
generic <typename T>
void AssociateWith(System::Linq::Expressions::Expression<Func<T, System::Object ^> ^> ^ expression);public void AssociateWith<T>(System.Linq.Expressions.Expression<Func<T,object>> expression);member this.AssociateWith : System.Linq.Expressions.Expression<Func<'T, obj>> -> unitPublic Sub AssociateWith(Of T) (expression As Expression(Of Func(Of T, Object)))Type Parameters
- T
The type that is queried against.
If the type is unmapped, an exception is thrown.
Parameters
- expression
- Expression<Func<T,Object>>
Identifies the query to be used on a particular one-to-many field or property. Note the following:
If the expression does not start with a field or property that represents a one-to-many relationship, an exception is thrown.
If an operator other than a valid operator appears in the expression, an exception is thrown. Valid operators are as follows:
Where
OrderBy
ThenBy
OrderByDescending
ThenByDescending
Take
Examples
In the following example, the inner loop iterates only over those Orders that have not been shipped today.
Northwnd db = new Northwnd(@"c:\northwnd.mdf");
DataLoadOptions dlo = new DataLoadOptions();
dlo.AssociateWith<Customer>(c => c.Orders.Where(p => p.ShippedDate != DateTime.Today));
db.LoadOptions = dlo;
var custOrderQuery =
from cust in db.Customers
where cust.City == "London"
select cust;
foreach (Customer custObj in custOrderQuery)
{
Console.WriteLine(custObj.CustomerID);
foreach (Order ord in custObj.Orders)
{
Console.WriteLine("\t {0}",ord.OrderDate);
}
}
Dim db As New Northwnd("c:\northwnd.mdf")
Dim dlo As DataLoadOptions = New DataLoadOptions()
dlo.AssociateWith(Of Customer)(Function(c As Customer) _
c.Orders.Where(Function(p) p.ShippedDate <> DateTime.Today))
db.LoadOptions = dlo
Dim custOrderQuery = _
From cust In db.Customers _
Where cust.City = "London" _
Select cust
For Each custObj In custOrderQuery
Console.WriteLine(custObj.CustomerID)
For Each ord In custObj.Orders
Console.WriteLine("{0}{1}", vbTab, ord.OrderDate)
Next
Next
Remarks
For information about how to avoid cycles, see DataLoadOptions.
Applies to
.NET Framework 4.8.1 and other versions
| Product | Versions |
|---|---|
| .NET Framework | 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |