Batch Update SObject in Salesforce.Com (VB.Net)
I’m sharing this code because I know a lot of new salesforce developers are pulling their hair out looking for concrete samples on how to do API batch update. Yes it took me awhile to be able to solve this problem. APEX API documentation doesn’t give it all and it’s frustrating…
So much for that, here’s how I did it. My sample is updating a custom field in Opportunity Object using VB.Net.
Dim arrUpdateID As New ArrayList 'This ArrayList holds the Opportunity IDs I need to update, I didn't included the query - that will be your task Dim objOppx(199) As Opportunity For d = d To arrUpdateID.Count - 1 Dim updateOppx As New Opportunity updateOppx.Id = arrUpdateID(d) ' You need an ID when you update updateOppx.Downloaded__c = True ' This is a checkbox in SFDC where I'm setting it to true updateOppx.Downloaded__cSpecified = True ' This is required when updating a boolean field objOppx(d) = updateOppx ' Storing opportunity values to objOppx which is an array of Oppty Next Dim sr() As SaveResult = sfdc.update(objOppx) ' This is where the updating happens, this line of code should be outside the loop For j As Integer = 0 To sr.Length - 1 Dim msgerr As String If Not sr(j).success Then msgerr = "Error updating Opportunity ID: " + sr(j).id + ". The error was: " _ + sr(j).errors(0).message End If Next
Note: You can only update 200 records in an Object at a time due to Governor limits, so you need to make some work around with that issue. I have done that through chunking up my array of IDs to update. I’ll leave that up to you! 
I hope this post helps! There will be more to come as I learn Salesforce.com and APEX programming.
Stay tuned!