Basic CRUD Question for WCF Plain Services

[Steven]

I am building a n-tier app, and used the OpenAccess to generate the classes for my postgresql db.   On the client end, I retrieve a list DTO for one of my objects of type project (which is mapped eventually to a projects table).   I can retrieve a single project of type ProjectDto or retrieve List<ProjectDto> projects with no problem.   I retrieve them through the WCF Plain Web Services.   I am having a problem when trying to create a new Project item and persisting it.

I tried the following:

// This is the plain web service
TestAdminServices.AdministrationServiceClient client = new TestAdminServices.AdministrationServiceClient();

List<TestAdminServices.ProjectsDto> projs= client.ReadProjectses(); //return a list of current projects

// Now create a new project
TestAdminServices.ProjectsDto prj = new TestAdminServices.ProjectsDto();

prj.Comments = "First Created by code";

prj.CreationDate = DateTime.Now;

prj.ModificationDate = prj.CreationDate;

prj.DatabaseName = "IBET_Data";

prj.MapName = "Hello Steve";

prj.ProjectName = "IBEt_MAIN";

// now persist it

client.UpdateProjects(prj);  // <-  THIS GENERATES "An object key cannot be resolved from string" 

 

How can I create a new project object and have it persist back to the database?    Any help or suggestions would be appreciated.

Steve

 

 

 

[Kristian Nikolov]

Hi Steven,

The reason for the exception you are encountering is that the client.UpdateProjects() method is used to update a project which already exists in your database. In order to persist a new project in the database you need to use the Create method of the service, in your case CreateProjects(), which is present for each of your DTO`s.  The snippet below is based on the code you provided and illustrates how to persist a new Projects entity:

TestAdminServices.AdministrationServiceClient client = new TestAdminServices.AdministrationServiceClient();

TestAdminServices.ProjectsDto prj = new TestAdminServices.ProjectsDto();

prj.Comments = "First Created by code";

prj.CreationDate = DateTime.Now;

prj.ModificationDate = prj.CreationDate;

prj.DatabaseName = "IBET_Data";

prj.MapName = "Hello Steve";

prj.ProjectName = "IBEt_MAIN";

//persisting the project
client.CreateProjects(prj);

You may also take a look at our Samples Kit. Under the tab N-Tier Development you will find detailed examples of WCF Plain Services integrated with both WPF and WinForms. The samples are named Sofia Car Rental - WCF Plain Services and Sofia Car Rental - WCF Plain Services with Windows Forms.

I hope that helps.

Regards,
Kristian Nikolov
Telerik