title: Grails: How can I create named unique constraint for multiple columns?
body: <p>How can I create named unique constraint for multiple columns?</p>
  
  <p>I've three classes:</p>
  
  <pre><code>class Descriptor {
      // some columns
  }
  
  class Protein {
      // some columns
  }
  
  class DescriptorValue {
      // some columns
      static belongsTo = [protein: Protein, descriptor: Descriptor]
      static constraints = {
          protein(unique:['descriptor'])
      }
  }
  </code></pre>
  
  <p>GORM creates an index with an auto generated name that is different for different environments. How can I specify its name?</p>