Add STI Discrimination on Reference Associations (#2041)

* Update SqlTreeNodeBean#appendFromBaseTable to add
discriminator values to the join
* Update tests to reflect new generated SQL

src/test/java/org/tests/inheritance/model/Configurations.java

@@ -17,12 +17,13 @@ public class Configurations {
   @OneToMany
   private List<GroupConfiguration> groupConfigurations;
 
+  @OneToMany
+  private List<ProductConfiguration> productConfigurations;
 
   public Integer getId() {
     return id;
   }
 
-
   public void setId(Integer id) {
     this.id = id;
   }
@@ -39,13 +40,25 @@ public class Configurations {
     return groupConfigurations;
   }
 
-
   public void setGroupConfigurations(List<GroupConfiguration> groupConfigurations) {
     this.groupConfigurations = groupConfigurations;
   }
 
-  public void add(GroupConfiguration groupConfiguration) {
+  public void addGroupConfiguration(GroupConfiguration groupConfiguration) {
     groupConfiguration.setConfigurations(this);
     groupConfigurations.add(groupConfiguration);
   }
+
+  public List<ProductConfiguration> getProductConfigurations() {
+    return productConfigurations;
+  }
+
+  public void setProductConfigurations(List<ProductConfiguration> productConfigurations) {
+    this.productConfigurations = productConfigurations;
+  }
+
+  public void addProductConfiguration(ProductConfiguration productConfiguration) {
+    productConfiguration.setConfigurations(this);
+    productConfigurations.add(productConfiguration);
+  }
 }