title: One-to-Many With Composite Keys and Different Column Names in Grails
body: <p>This is a syntax question.  I want a one-to-many relationship between Foo -> Bar (simplified here):</p>
  
  <pre><code>class Foo {
      String fooPK1, fooPK2
  
      static mapping = {
          id composite: ["fooPK1", "fooPK2"]
      }
  
      static hasMany = [bars: Bar]
  }
  
  class Bar {
      String fooPK1, dumbNameForFooPK2, barPK1, barPK2
      Foo myFoo
  
      static mapping = {
          id composite: ["barPK1", "barPK2"]
          columns {
              myFoo[:] {
                  column name: "FOO_PK_1"
                  column name: "?????????????"
              }
          }
      }
  }
  </code></pre>
  
  <p>In this case, obviously Foo.fooPK1 maps to Bar.fooPK1, but i need Foo.fooPK2 to map to Bar.dumbNameForFooPK2.  Hopefully this makes sense.</p>
  
  <p>My problem is I have no idea what the syntax is supposed to be (or if there's a better way to do this!) and from what I could find, the grails documentation wasn't really helpful.</p>