如何更改Grails域类ID字段的名称？

Question

I have a Grails 2.2.3 domain class called FundType that I am trying to map to a legacy database table. It has two fields: code and description . I would like the id to be called code anytime I use the domain class and preferably on any of the generated scaffolding. But every time I use the name key on id I get this exception:

| Error 2013-07-24 09:38:44,855 [localhost-startStop-1] ERROR context.GrailsContextLoader  - Error initializing the application: Error evaluating ORM mappings block for domain [com.company.scholallow.FundType]:  null
Message: Error evaluating ORM mappings block for domain [com.company.scholallow.FundType]:  null

This is what my domain class consists of:

class FundType {

    String id
    String description

    static mapping = {
        id column: 'fund_code', generator: 'assigned', name: 'code'
        description column: 'fund_desc'
    }
}

And anytime I am using a FundType instance I would like to call code like fundTypeInstance.code and NOT fundTypeInstance.id . This will make it more user friendly for me because I'm dealing with something called code, not id.

So I would like to know is what I'd like to do possible? And what am I doing wrong in my domain class that is causing this ORM mappings error?

Edit:

Okay, so I changed my domain class to the following and I am getting a FundType not found with ID null error.

class FundType {

    String code
    String description

    static mapping = {
        id generator: 'assigned', name: 'code'
        code column: 'fund_code'
        description column: 'fund_desc'
    }
}

I added some sql logging to see what Hibernate is doing and this is what was output: select * from ( select this_.FUND_CODE as RTVFTYP1_1_0_, this_.FUND_DESC as RTVFTYP2_1_0_ from RTVFTYP this_ ) where rownum <= ?

Answer 1

Use String code instead of String id in the domain class.

You are deliberately mentioning to the GORM that I want to use the property code which maps to table column fund_code whose value is assigned as the id (primary key). In that case, you just need to have the property code defined in the domain class instead of the id .

Answer 2

(I'm answering the fix that worked for me for future use by other programmers)

@dmahapatro was right, I needed to add String code .

It looks like naming the id something different just doesn't play well with Grails dynamic scaffolding. I did some tests and I can still use FundType.get(code) and it will return the object just as if I passed in an id. I can also do FundType.findByCode(code) .

It looks like I have to change the scaffolded controller to expect a String id instead of the default Long id. I also have to change the scaffolded list view to send fundTypeInstance.code instead of fundTypeInstance.id to the show controller, but I suspect that adding a getId() that just returns this.code will fix that.