Mark and src/groovy base domain class

[Bill James]

Mark,

I remember you asking about using src/groovy classes as base classes for Domains, and I was sure we'd done that, so I tried it again.

Steps:

Create new grails project

Create class in src/groovy/dom called BaseDom.groovy like this:

package dom


class BaseDom {

    String baseString
    Long baseLong
}

Create a new Domain ChildDom.groovy in the domains directory like this (I added some mappings for fun:

package test.domain
import dom.BaseDom
class ChildDom extends BaseDom {
    String childString
    Long childLong
    Double childDouble
    static constraints = {
        baseString( nullable: true )
        childLong( nullable: false )
        childDouble( nullable: true )
    }
    static mapping = {
        baseString( column: 'bstr' )
    }
}

You should be able to see what DDL will be generated by running schema-export:

grails dev schema-export generate .\ddl.sql

That should show you the DDL it would use to generate a single table for ChildDom containing the fields from BaseDom:

    drop table child_dom if exists;
    create table child_dom (
        id bigint generated by default as identity,
        version bigint not null,
        base_long bigint not null,
        bstr varchar(255),
        child_double double,
        child_long bigint not null,
        child_string varchar(255) not null,
        primary key (id)
    );

Is this what you were asking about?

[Mark Fortner]

Hi Bill,

That's what I was doing.  Except, when I started up, it threw an exception -- I don't remember which one.  I remember spending a day trying to track it down, and then just decided to brute force it, and create a POGO to domain object copying method.  When I get a chance I'll try and reproduce the error.

Mark