绿道树实体实现：父子来自同一实体，不编译

我需要一些关于使用ORM GREENDAO定义的实体进行树表示的建议。

事实上，我不能用我的反射属性生成dao文件。我尝试实现一个简单的CATEGORIES树。

类别1可以有一个类别0作为父类别，类别1也可以有几个类别作为子类别。因此，两个外键指向与源和目标相同的实体类别。

我尝试了绿道在他们的网站上提出的代码来制作一个树实体，请参阅页面上的"建模树关系（示例）"一节。

我的问题代码：

Entity categories = schema.addEntity("CATEGORIES");
categories.addIdProperty().primaryKey();
Property parentId= categories.addLongProperty("parentId").notNull().getProperty();
ToOne ParentCat = categories.addToOne(categories, parentId);
ParentCat.setName("parentId");
Property childrenId= categories.addLongProperty("childrenId").notNull().getProperty();
ToMany ChildrenCat = categories.addToMany(categories, childrenId);
ChildrenCat.setName("children");

我从编译器那里得到了这些例外：

greenDAO Generator
Copyright 2011-2015 Markus Junginger, greenrobot.de. Licensed under GPL V3.
This program comes with ABSOLUTELY NO WARRANTY
*Exception in thread "main" java.lang.RuntimeException: Currently only single FK columns are supported: ToOne 'parentId' from CATEGORIES to CATEGORIES
    at de.greenrobot.daogenerator.ToOne.init3ndPass(ToOne.java:91)
    at de.greenrobot.daogenerator.Entity.init3rdPassRelations(Entity.java:603)
    at de.greenrobot.daogenerator.Entity.init3rdPass(Entity.java:596)
    at de.greenrobot.daogenerator.Schema.init3rdPass(Schema.java:185)
    at de.greenrobot.daogenerator.DaoGenerator.generateAll(DaoGenerator.java:91)
    at de.greenrobot.daogenerator.DaoGenerator.generateAll(DaoGenerator.java:79)
    at Apptree_DAO_Generator.main(Apptree_DAO_Generator.java:13)*

或

*Exception in thread "main" java.lang.RuntimeException: Source properties do not match target properties: ToMany 'children' from CATEGORIES to CATEGORIES
    at de.greenrobot.daogenerator.ToMany.init2ndPass(ToMany.java:59)
    at de.greenrobot.daogenerator.Entity.init2ndPass(Entity.java:517)
    at de.greenrobot.daogenerator.Schema.init2ndPass(Schema.java:179)
    at de.greenrobot.daogenerator.DaoGenerator.generateAll(DaoGenerator.java:90)
    at de.greenrobot.daogenerator.DaoGenerator.generateAll(DaoGenerator.java:79)
    at Apptree_DAO_Generator.main(Apptree_DAO_Generator.java:13)*

因此，同一实体表的外键似乎有问题。还有别的办法吗？

Entity categories = schema.addEntity("CATEGORIES");
categories.addIdProperty().primaryKey();
Property parentId= categories.addLongProperty("parentId").notNull().getProperty();
ToOne ParentCat = categories.addToOne(categories, parentId);
ParentCat.setName("parent");
ToMany ChildrenCat = categories.addToMany(categories, parentId);
ChildrenCat.setName("children");

categoryB.setParent(categoryA);
categoryC.setParent(categoryB);
categoryD.setParent(categoryB);