#1740 and #1744 Don't include the discriminator column on Inheritance query on a type that has no sub-types

Fix for #1740

src/test/java/org/tests/aggregateformula/IAFBaseSegment.java

@@ -0,0 +1,18 @@
+package org.tests.aggregateformula;
+
+import javax.persistence.DiscriminatorColumn;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Inheritance;
+import javax.persistence.Table;
+
+@Entity
+@Inheritance
+@Table(name = "iaf_segment")
+@DiscriminatorColumn(name = "ptype")
+public class IAFBaseSegment {
+
+  @Id
+  private Long id;
+
+}