How to automate entry of external column data in BCS?

Question

I have a document library, Resumes, that has a large number of resumes in it. There is a regular column on that library, called EmployeeID, that is already populated. I have an external content type ( ECT ) that is mapped to a table that lists EmployeeID and several other columns of information. I added this ECT to the library as an External Column.

I am looking for a good way to automatically go through all items in the document library, and copy the value from the "regular" EmployeeID column into the External EmployeeID column and have it update the other columns from the ECT. Any techniques are useful (PowerShell, Object Model, Workflow?) When we have tried this in the past with workflows the setting of the External Column did not report failure, but didn't actually trigger a lookup of the other data and the value didn't seem to actually get saved.

[Update] I have been working on this and am getting closer. I am using PowerShell to access the list and set the external column ID field to the value I want it to be.

The problem is that it doesn't seem to be triggering a lookup of the external data when that field is set.

my "list" (a document library) has a few normal fields and a set of external columns mapped to an ECT "EmplData".

When you use the GUI to add or edit the properties of an item, it works. When I use PowerShell to do the following:

$spList = $spWeb.Lists["Resumes"]
$spListItem = $spList.GetItemById(1)
$spListItem["EmplData_ID"] = "00300"   
$spListItem.Update()

Sometime the external ID field gets updated when I the refresh the web page, other times it says "(blank)". In all cases it does not load in the other fields.

Is there some Update method that updates the rest of the elements? I gather from research that these are called "secondary fields", is the method to update the secondary fields based on the external item ID available in PowerShell cmdlets someplace?

[Update] I am finding that if I use:

$spListItem["EmplData"] = "000300"

instead of $spListItem["EmplData_ID"] = "00300" it gets around the problem of the column showing "(blank)".

I still need to figure how to make it update the other external columns (also known as "secondary columns" I think)

Answer 1

Thus far, using the object model has been the only way I have been able to successfully do this. I encountered the same issues as you when using PowerShell.

Using Jaspers' post SP2010: Setting BCS column and related fields as my guide, I used the following code to iterate through all the items in my Resumes document library, read the value from the "regular" EmployeeID field for each item, set the "external" EmplData_ID value, then set all the "secondary field" values based on this value.

using (SPSite site = new SPSite(SPContext.Current.Site.ID))
{
    using (SPWeb web = site.OpenWeb(SPContext.Current.Web.ID))
    {
        web.AllowUnsafeUpdates = true;
        SPList resumesList = web.Lists["Resumes"];

        foreach (SPListItem item in resumesList.Items)
        {
            SPBusinessDataField dataField = item.Fields["EmplData_ID"] as SPBusinessDataField;
            // Set the "external" Employee ID field value
            item[dataField.RelatedField] = item["EmployeeID"];
            // Now set all the secondary field values
            SetSecondaryFields(item, dataField, GetEntityInstance("http://sp2010srv", "Employee", int.Parse(item["EmployeeID"].ToString())));
            item.UpdateOverwriteVersion();
        }
    }
}

Here is the code for the two helper methods GetEntityInstance and SetSecondaryFields:

private static IEntityInstance GetEntityInstance(string nameSpace, string entityName, int entityId)
{
    BdcService service = SPFarm.Local.Services.GetValue<BdcService>();
    IMetadataCatalog catalog = service.GetDatabaseBackedMetadataCatalog(SPServiceContext.Current);
    IEntity entity = catalog.GetEntity(nameSpace, entityName);
    ILobSystemInstance LobSysteminstance = entity.GetLobSystem().GetLobSystemInstances()[0].Value;
    IEntityInstance entInstance = null;

    // Get methods collection 
    foreach (KeyValuePair<string, IMethod> method in entity.GetMethods())
    {
        // Get current method's instance 
        IMethodInstance methodInstance = method.Value.GetMethodInstances()[method.Key];
        // Execute specific finder method. 
        if (methodInstance.MethodInstanceType == MethodInstanceType.SpecificFinder)
        {
            // Create new identity 
            Identity id = new Identity(entityId);
            // Execute specific finder method and get the entity instance 
            entInstance = entity.FindSpecific(id, entity.GetLobSystem().GetLobSystemInstances()[0].Value);
        }
    } 

    return entInstance;
}

private static void SetSecondaryFields(SPListItem listItem, SPBusinessDataField dataField, IEntityInstance entityInstance)
{
    // Convert the entity to a formatted datatable
    DataTable dtBDCData = entityInstance.EntityAsFormattedDataTable;

    // Set the BCS field itself (Display Value)
    listItem[dataField.Id] = dtBDCData.Rows[0][dataField.BdcFieldName].ToString();

    // Get the specific finder method to get the columns that returns
    IMethodInstance method = entityInstance.Entity.GetMethodInstances(MethodInstanceType.SpecificFinder)[0].Value;
    ITypeDescriptorCollection oDescriptors = method.GetReturnTypeDescriptor().GetChildTypeDescriptors()[0].GetChildTypeDescriptors();

    // Set the column names to the correct values
    foreach (ITypeDescriptor oType in oDescriptors)
    {
        if (oType.ContainsLocalizedDisplayName())
        {
            if (dtBDCData.Columns.Contains(oType.Name))
            {
                dtBDCData.Columns[oType.Name].ColumnName = oType.GetLocalizedDisplayName();
            }
        }
    }

    // get the secondary field display names; these should be set
    string[] sSecondaryFieldsDisplayNames = dataField.GetSecondaryFieldsNames();

    // loop through the fields and set each column to its value
    foreach (string columnNameint in sSecondaryFieldsDisplayNames)
    {
        Guid gFieldID = listItem.Fields[String.Format("{0}: {1}", dataField.Title, columnNameint)].Id;
        listItem[gFieldID] = dtBDCData.Rows[0][columnNameint].ToString();
    }
}

Answer 2

Take a look at SharePoint Bdc request library. This group of classes lets to make simple requests for values from external data source, using a BDC Entity Instance Identifier(s) or a value of a certain BDC Entity field. Get required entity instance as a DataTable oject and then set a SPListItem's fields.

Answer 3

The Referenced Field value is encoded. You have to use DecodeEntityInstanceId to get it:

http://msdn.microsoft.com/en-us/library/microsoft.sharepoint.businessdata.infrastructure.entityinstanceidencoder_methods

Answer 4

I used some of this code to create a web part. My code is available here: http://rrfreeman.blogspot.com/2013/06/bcs-bdc-external-data-lookup-field.html