When should one try to eliminate a switch statement? [duplicate]

Answer 1

You are right to suspect this switch statement: any switch statement that is contingent on the type of something may be indicative of missing polymorphism (or missing subclasses).

TallJoe's dictionary is a good approach, however.

Note that if your enum and database values were integers instead of strings, or if your database values were the same as the enum names, then reflection would work, e.g. given

public enum DiscountType : int
{
    Unknown = 0,
    Discountable = 1,
    Loss = 2,
    Other = 3
}

then

p.DiscountType = Enum.Parse(typeof(DiscountType), 
    (string)reader[discountTypeIndex]));

would suffice.