C# LINQ select from list

i have a list of event Ids returned from an xml document as shown below

public IEnumerable<EventFeed> GetEventIdsByEventDate(DateTime eventDate)
    {

        return (from feed in xmlDoc.Descendants("Show")
                from ev in feed.Elements("Event")
                where Convert.ToDateTime(ev.Attribute("Date").Value).ToShortDateString() == eventDate.ToShortDateString()
                select new EventFeed()
                {
                    EventShowCode = feed.Attribute("Code").Value
                }).ToList();  
    }

i now need to query my database to match events that equal the eventIds returned from the above method. so i would have something like:

select * from eventsdb where eventId in GetEventIdsByEventDate()

how can i do this using LINQ

i cant seem to get any of the answers working.

this is the method that looks up the eventIds from an XML feed

public IList<EventsDetails> GetEventIds(DateTime eventDate)
    {

        var eventids = (from feed in xmlDoc.Descendants("Show")
                        from ev in feed.Elements("Event")
                        where Convert.ToDateTime(ev.Attribute("Date").Value).ToShortDateString() == eventDate.ToShortDateString()
                        select new EventsDetails()
                        {
                            EventId = feed.Attribute("Code").Value
                        }).ToList();

        return eventids;
    }

this is the method that looks up the events in my database

public IEnumerable<EventFeed> GetAllEventsFromDatabase()
    {
        var allEvents = from eventsList in GetEventsList()
                        select new EventFeed()
                        {
                            EventName = eventsList.Title,
                            EventSummary = eventsList.Introduction,
                            EventShowCode = eventsList.EventId,