DML requires SObject or SObject list type error

Question

I got some advice a couple days ago to improve my batch updater class. I have been working on it but am getting a compile error. I get the error:

DML requires SObject or SOBject list type: Map Line 20

The line is where I update the map pipelines. Why do I get this if I have Map pipelines = new Map(); in the method?

Code example:

global void execute(Database.BatchableContext BC, List<Revenue_Pipeline_Schedule__c> scope) {

    Map<Id, Revenue_Pipeline__c> pipelines = new Map<Id, Revenue_Pipeline__c>();

    for (Revenue_Pipeline_Schedule__c schedule : scope)
    {
        Id pipelineId = schedule.Revenue_Pipeline__c;
        pipelines.put(pipelineId, new Revenue_Pipeline__c(Id=pipelineId));
    }
    // now all keys are initialized

    for (Revenue_Pipeline_Schedule__c schedule : scope)
    {
        SObjectField field = RevenuePipelineScheduleUpdaterHelper.dateToField.get(schedule.Date__c);
        if (field != null)
        {
            pipelines.get(schedule.Revenue_Pipeline__c).put(field, schedule.Amount__c);
        }
    }   
    update pipelines;
}

Answer 1

You can't update SObjects using a map. You have to do:

update pipelines.values();