"SchemaManagementException: SQL strings added more than once" in Hibernate

Issue

• Two different entities in a single persistence unit are mapped to tables by the same name which reside in different database schemas

• The tables each have unique constraints on identically named, non-primary key properties

  @Entity
  @Table(name = "employee", schema = "testone")
  public class EmployeeOne {
          @Id
          private String name;
  
          @Column(unique = true)
          private String title;
          ...
  }
  
  @Entity
  @Table(name = "employee", schema = "testtwo")
  public class EmployeeTwo {
          @Id
          private String name;
  
          @Column(unique = true)
          private String title;
          ...
  }
  

• When Hibernate is used to generate the database artifacts, (e.g. hibernate.hbm2ddl.auto=create-drop), an exception is raised

  ... org.hibernate.tool.schema.spi.SchemaManagementException: SQL strings added more than once for: employee.UK-UK_....
      at org.hibernate.tool.schema.internal.SchemaCreatorImpl.checkExportIdentifier(SchemaCreatorImpl.java:408)
      at org.hibernate.tool.schema.internal.SchemaCreatorImpl.createFromMetadata(SchemaCreatorImpl.java:347)
      at org.hibernate.tool.schema.internal.SchemaCreatorImpl.performCreation(SchemaCreatorImpl.java:165)
      at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:134)
      at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:120)
      at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:148)
      at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:65)
      at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:478)
      at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:423)
      at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:880)
      ...