Question

I have the following classes:

class Catalog {
  static mapping = {
    id composite:['name', 'manufacturer']
    columns {
      name column:'cat_name'
      manufacturer column:'manuf_id'
    }
  }
  String name
  Manufacturer manufacturer
}

class Order {
  static mapping = {
    columns {
      // How to rename foreign keys as cat_name, manuf_id?
    }
  }
  Catalog catalog // creates catalog_name, catalog_manufacturer_name
}

Presently, an Order table is generated with the attributes catalog_name and catalog_manufacturer_name (which reference the composite primary keys of the Catalog table).

I need to rename these generated columns to cat_name and manuf_id in the Order table to work with an existing database. Is this possible, and if so, how?

Answer 1

It’s not possible using GORM configuration, but you can do it with a custom Configuration class:

package com.foo.bar;

import java.util.Collection;
import java.util.Iterator;

import org.codehaus.groovy.grails.orm.hibernate.cfg.DefaultGrailsDomainConfiguration;
import org.hibernate.MappingException;
import org.hibernate.mapping.Column;
import org.hibernate.mapping.PersistentClass;
import org.hibernate.mapping.RootClass;

public class CompositeAwareHibernateConfiguration extends DefaultGrailsDomainConfiguration {

   private static final long serialVersionUID = 1;

   private boolean _alreadyProcessed;

   @SuppressWarnings("unchecked")
   @Override
   protected void secondPassCompile() throws MappingException {
      super.secondPassCompile();

      if (_alreadyProcessed) {
         return;
      }

      for (PersistentClass pc : (Collection<PersistentClass>)classes.values()) {
         if (pc instanceof RootClass) {
            RootClass root = (RootClass)pc;
            if ("com.foo.bar.Order".equals(root.getClassName())) {
               for (Iterator iter = root.getTable().getColumnIterator(); iter.hasNext(); ) {
                  Column column = (Column)iter.next();
                  if ("catalog_name".equals(column.getName())) {
                     column.setName("cat_name");
                  }
                  else if ("catalog_manufacturer_id".equals(column.getName())) {
                     column.setName("manuf_id");
                  }
               }
            }
         }
      }

      _alreadyProcessed = true;
   }
}

Put the class in src/java and register it in DataSource.groovy:

dataSource {
   pooled = true
   driverClassName = ...
   username = ...
   password = ...
   configClass = com.foo.bar.CompositeAwareHibernateConfiguration
}