具有完全外部联接的SQL到LINQ转换

Question

SELECT* FROM Event FULL OUTER JOIN Booking ON Event.eventId = Booking.eventId
WHERE(Booking.userId = 3) AND (Booking.bookingId IS NULL) 
OR (Event.eventId IS NULL) 
OR (Booking.eventId IS NULL)

This is what i have converted so far however i have encounter an error at "&& bookings.bookingId == null"

The error message is " Operator '&&' cannot be applied to operands of type 'int' and 'bool"

How do you fix it?

            User student = (User)Session["user"];
        var db = new EMS.Models.dbEMSEntities();
        IQueryable<Event> query =  from events in db.Events
                                   join bookings in db.Bookings
                                   on events.eventId equals bookings.eventId
                                   where bookings.userId = student.userId 
                                   && bookings.bookingId == null || events.eventId == null || bookings.eventId == null

Answer 1

where bookings.userId = student.userId && bookings.bookingId == null || events.eventId == null || bookings.eventId == null

is being evaluated as

where bookings.userId = (student.userId && bookings.bookingId == null) || events.eventId == null || bookings.eventId == null

Because of this, (int)userId && (bool)(bookingId == null) is comparing an int against a bool which violates the language Make sure you use "==" as an evaluation and not the assignment "=".

Answer 2

   User student = (User)Session["user"];
        var db = new EMS.Models.dbEMSEntities();
        IQueryable<Event> query =  from events in db.Events
                                   join bookings in db.Bookings
                                   on events.eventId equals bookings.eventId
                                   where (bookings.userId == student.userId)
                                   && (bookings.bookingId == null) || (events.eventId == null) || (bookings.eventId == null)