An internal database error occurred in the Business Data Connectivity Shared service (BDC)

Firstly i want to say that i run across on this error not quite (as i thought) relating to BDC.. but:

My initial goal was simple - create some custom list in SP2010 with Lookup (information already on this site) fields. When i tried to do that i got following message:

So.. BDC service is related with creating Lookup type fields in SharePoint. Time ago we moved our SharePoint databases to new SQL server, but we didn't move our BDC db.. so i started to realize where is the problem. I have to create new BDC service application with new db in our new sql server + delete old BDC application (relationships), point my web application to new BDC service application.

I looked in SP Central Adminstration page for Service Applications (Application management -> Manage Service Applications).

1. Deleted old BDC application.
2. Created new BDC.
3. Point web application to new BDC (Application management -> Service Applications -> Service Application Associations)
4. IISRESET

But unfortuneatlly when i tried to create Lookup field i got new error saying:
Entity (External Content Type) cannot be found with Namespace = '', Name = 'New external content Type'

Solution:

Previously i had some (With old BDC application) External Lists with custom external content types in them, so when we are creating Lookup fields, SharePoitn is looking for those content types and they didn't exist any more, so i DELETED THOSE OLD EXTERNAL LISTS.

This item is no longer available. It may have been deleted by another user

There are many articles about this SharePoint error message: "This item is no longer available. It may have been deleted by another user"

Mike Smith's Tech Training Notes and
http://girishm.blog.com/2010/07/11/this-item-is-no-longer-available-it-may-have-been-deleted-by-another-user-click-ok-to-refresh-the-page/

These solutions didn't work for me!
IN MY CASE I SIMPLY DELETE INTERNET TEMPORARY FILES & COOKIES!!!

SCSM Creating Manual Activity for Incident in C#

Some time ago I had to develope application that could connect two systems: Microsoft Dynamics CRM & SCSM (Microsoft System Center Service Manager). The main purpose of this application is to synchronize data between two applications.

In this article i will show you only some little part (but maybe one of the  toughest for me...) of my application code.
I will continue to post some other usefull parts from this project. 

The code consists of 3 main steps:

1. Create relationship between incident & manual activity
2. Create manual activity
3. Assign created activity to incident

There is good post about creating incident in SCSM which really helped me out: http://blogs.technet.com/b/servicemanager/archive/2009/08/09/the-system-center-platform-in-service-manager-part-3-the-data-access-service-try-it.aspx

//Create relationship between incident & manual acticvity
ManagementPackRelationship workItemContainsActivityRelationship =
mg.EntityTypes.GetRelationshipClass(new Guid("2DA498BE-0485-B2B2-D520-6EBD1698E61B"));
                                             
CreatableEnterpriseManagementRelationshipObject AssignedToIncident = 
new CreatableEnterpriseManagementRelationshipObject(mg, workItemContainsActivityRelationship);

//Create Manual Activity
CreatableEnterpriseManagementObject activityItemObject = 
new CreatableEnterpriseManagementObject(mg, classManualActivity);
Guid newActivityGuid = Guid.NewGuid();
                                             
activityItemObject[classManualActivity, "Id"].Value = newActivityGuid.ToString();                                              
activityItemObject[classManualActivity, "Title"].Value = "<Title>";
activityItemObject[classManualActivity, "Description"].Value = "<Description>";
                                             
EnterpriseManagementObjectGenericCriteria genericCr = 
new EnterpriseManagementObjectGenericCriteria("Id == '" + <SCSM Incident Id>.ToString() + "'");
IObjectReader<EnterpriseManagementObject> reader = mg.EntityObjects.GetObjectReader<EnterpriseManagementObject>(genericCr, ObjectQueryOptions.Default);

 if (reader != null && reader.Count > 0) {

foreach (EnterpriseManagementObject obj in reader) {

AssignedToIncident.SetSource(obj);

AssignedToIncident.SetTarget(activityItemObject);

IncrementalDiscoveryData dd = new IncrementalDiscoveryData();

dd.Add(activityItemObject);

dd.Add(AssignedToIncident);

dd.Overwrite(mg);

//Assign Manual Activity to Incident

AssignedToIncident.Commit();

         }

}

How to get all SharePoint Users with web services in c#

SPservice.UserGroup usergroup = new SPservice.UserGroup();
usergroup.Credentials = System.Net.CredentialCache.DefaultCredentials;

XmlNode allusers = usergroup.GetAllUserCollectionFromWeb();

foreach (XmlNode child in allusers.ChildNodes) {
                            foreach (XmlNode item in child) {
                                  foreach (XmlAttribute atr in item.Attributes) {
                                              if (atr.Name.ToString() == "LoginName") {
                                              MessageBox.Show(atr.OuterXml);
                                              }
                              }
                }
}

SPservice - name of web reference in your visual studio project with URL:
http://<your server name>/_vti_bin/usergroup.asmx

CRM 4 how to retrieve custom attribute value in C#

DynamicEntity someEntity;

TargetRetrieveDynamic retrieveTarget = new TargetRetrieveDynamic();

retrieveTarget.EntityId = <id of entity>;

retrieveTarget.EntityName = EntityName.<entity name>.ToString();

RetrieveRequest retrieveRequest = new RetrieveRequest();

retrieveRequest.ColumnSet = new ColumnSet(new string[] { "your_custom_attribute" });

retrieveRequest.ReturnDynamicEntities = true;

retrieveRequest.Target = retrieveTarget;

RetrieveResponse retrieveResponse = (RetrieveResponse)service.Execute(retrieveRequest);

someEntity = retrieveResponse.BusinessEntity as DynamicEntity;

String result = (String)someEntity["your_custom_attribute"];

String value = result.Value.ToString();