什么时候应该使用枚举而不是域，反之亦然？

Question

My context: User will add one of numerous type of company into himself in the form. For that form, I created enum to fill the listbox instead of pulling the database.

I will try my best to explain what my question is: In my context, whats the difference between using enum and domain for showing and save into database? Performance, logic, bestpractice?

Because when user saves a companyType , it will save an int into database, but I can see what description it is. using a method @Overide toString() .

Instead of using enum as code below, I could have created a domain with id and description moreover adding two registers into my db pulling into to form.

class Company{
    CompanyType companyType
}

Use this as enum

enum CompanyType {
    MARKET('Market', 1),
    SHOP('Shop', 2)
// ... etc of code
}

or use this as domain

class CompanyType {
    Long id
    String description
}

sorry for my bad english.

Answer 1

您应该考虑的主要因素是公司类型数据可能发生的变化，如果您能够列出将要使用的所有可能的公司类型，并且确定不会频繁更新，那么枚举是合理的选择，没有另一方面，如果需要更改表或POJO，则要更改，添加，更新和删除公司类型，则表和POJO类是正确的选择。

Answer 2

two points:

• performance: enum values are saved as a String (usually as enum.toString() ) in a db, and don't require any FK-relations and have less overhead during ORM transformations

• flexibility: enum values can be updated only with new deployment. If you need to change the value of the existing enum constant, you would have to migrate your data

I would use enums instead of a domain class, as the performance is usually more important