#642 - ENH: Add support for OneToMany expression isEmpty() / isNotEmpty() ... which is effectively an EXISTS and NOT EXISTS subquery

src/main/java/com/avaje/ebean/ExpressionFactory.java

@@ -246,6 +246,16 @@ public interface ExpressionFactory {
    */
   Expression notExists(Query<?> subQuery);
 
+  /**
+   * Is empty expression for collection properties.
+   */
+  Expression isEmpty(String propertyName);
+
+  /**
+   * Is not empty expression for collection properties.
+   */
+  Expression isNotEmpty(String propertyName);
+
   /**
    * Id Equal to - ID property is equal to the value.
    */