多条件查询

“the car is red and costs less than $10”:

Expression<Func<Car, bool>> theCarIsRed = c => c.Color == "Red";

Expression<Func<Car, bool>> theCarIsCheap = c => c.Price < 10.0;

IQueryable<Car> carQuery = …;

var query = carQuery.Where(theCarIsRed).Where(theCarIsCheap);

 

“the car is red or the car costs less than $10”

To combine lambda expressions, I can write:

Expression<Func<Car, bool>> theCarIsRed = c => c.Color == "Red";

Expression<Func<Car, bool>> theCarIsCheap = c => c.Price < 10.0;

Expression<Func<Car, bool>> theCarIsRedOrCheap = theCarIsRed.Or(theCarIsCheap);

var query = carQuery.Where(theCarIsRedOrCheap);