Session.FindObject(Type, CriteriaOperator) Method

Searches for the first object which matches the specified criteria.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v23.2.dll

NuGet Packages: DevExpress.Win.PivotGrid, DevExpress.Win.TreeMap, DevExpress.Xpo

NuGet Package: DevExpress.Xpo

Declaration

C#

public object FindObject(
    Type classType,
    CriteriaOperator criteria
)

VB.NET

Public Function FindObject(
    classType As Type,
    criteria As CriteriaOperator
) As Object

Parameters

Name	Type	Description
classType	Type	A Type object which represents the type of objects to search for.
criteria	CriteriaOperator	A CriteriaOperator descendant which represents the criteria to match persistent objects to.

Returns

Type	Description
Object	An object which represents the first persistent object that matches the specified criteria. null (Nothing in Visual Basic) if no persistent object which matches the criteria is found.

Remarks

The example below demonstrates how to use this method. Here, session is the Session instance.

C#

using DevExpress.Data.Filtering;
using DevExpress.Xpo;
// ...
Person personToUpdate = (Person)session.FindObject(typeof(Person), 
    CriteriaOperator.Parse("Name='Michael Suyama'"));
if(personToUpdate != null) {
    personToUpdate.Birthday = new DateTime(1986, 10, 31);
    session.Save(personToUpdate);
}

VB.NET

Imports DevExpress.Data.Filtering
Imports DevExpress.Xpo
' ...
Dim personToUpdate As Person = CType(session.FindObject(GetType(Person), _
    CriteriaOperator.Parse("Name='Michael Suyama'")), Person)
If personToUpdate IsNot Nothing Then
    personToUpdate.Birthday = New Date(1986, 10, 31)
    session.Save(personToUpdate)
End If

Persistent objects that are marked as deleted in the database (see Deferred and Immediate Object Deletion) are not included in the search.

Related GitHub Examples

The following code snippets (auto-collected from DevExpress Examples) contain references to the FindObject(Type, CriteriaOperator) method.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

XPO_how-to-connect-to-a-remote-data-service-instead-of-using-a-direct-database-connection-e4930/CS/ConsoleApplication1/Program.cs#L17

using(UnitOfWork uow = new UnitOfWork()) {
    if(uow.FindObject(typeof(Customer), new BinaryOperator("ContactName", "Alex Smith", BinaryOperatorType.Equal)) == null) {
        Customer custAlex = new Customer(uow);

XPO_how-to-create-a-data-caching-service-that-helps-improve-performance-in-distributed-e4932/CS/ConsoleApplication1/Program.cs#L26

{
    if (uow.FindObject(typeof(Customer), new BinaryOperator("ContactName", "Alex Smith", BinaryOperatorType.Equal)) == null)
    {

XPO_how-to-connect-to-remote-data-store-and-configure-wcf-end-point-programmatically-e5137/CS/E5137/Program.cs#L13

using(UnitOfWork uow = new UnitOfWork()) {
    if(uow.FindObject(typeof(Customer), new BinaryOperator("ContactName", "Alex Smith", BinaryOperatorType.Equal)) == null) {
        Customer custAlex = new Customer(uow) { ContactName = "Alex Smith", CompanyName = "DevExpress" };

VB.NET

XPO_how-to-connect-to-a-remote-data-service-instead-of-using-a-direct-database-connection-e4930/VB/ConsoleApplication1/Program.vb#L17

Using uow As New UnitOfWork()
    If uow.FindObject(GetType(Customer), New BinaryOperator("ContactName", "Alex Smith", BinaryOperatorType.Equal)) Is Nothing Then
        Dim custAlex As New Customer(uow)

XPO_how-to-create-a-data-caching-service-that-helps-improve-performance-in-distributed-e4932/VB/ConsoleApplication1/Program.vb#L21

Using uow As New UnitOfWork()
    If uow.FindObject(GetType(Customer), New BinaryOperator("ContactName", "Alex Smith", BinaryOperatorType.Equal)) Is Nothing Then
    Dim custAlex As New Customer(uow)

XPO_how-to-connect-to-remote-data-store-and-configure-wcf-end-point-programmatically-e5137/VB/E5137/Program.vb#L13

Using uow As New UnitOfWork()
    If uow.FindObject(GetType(Customer), New BinaryOperator("ContactName", "Alex Smith", BinaryOperatorType.Equal)) Is Nothing Then
        Dim custAlex As New Customer(uow) With {.ContactName = "Alex Smith", .CompanyName = "DevExpress"}