MongoDB将所有现有索引迁移到新数据库(MongoDB Migrate all existing indexes to new database)

 我不确定你的意思是“外键必须在OptIn中”。 您已通过@PrimaryKeyJoinColumn映射您的@OneToOne关联，这意味着您的实体将通过其ID值进行关联。 这也意味着： 
 
 
 
 您无法在@PrimaryKeyJoinColumn注释中指定列名称; 它们将取自两个实体的相应@Id列。 
 
 
 标记为LAZY是毫无意义的并且将被忽略; 可选的@OneToOne关联总是被热切地提取。 
 
 
 OptIn在这个关联中可选的唯一方法是如果数据库中没有给定ID的条目。 
 
 
 您使用的是何种Hibernate / Annotations版本？ 如果它们很老，那可能是Hibernate代码中的一个错误。 但是我相信如果你修正上面的（1）和（2），它应该可以工作。 

I'm not sure what you mean by "foreign key must be in OptIn". You've mapped your @OneToOne association via @PrimaryKeyJoinColumn which means your entities will be linked via their ID values. It also means that:
 
 
 
You can't specify column names within @PrimaryKeyJoinColumn annotation; they will be taken from appropriate @Id columns on both entities instead.
 
 
Marking fetch as LAZY is pointless and going to be ignored; optional @OneToOne associations are always eagerly fetched.
 
 
The only way OptIn would be optional on this association is if there was no entry with given ID in the database.
 
 
What Hibernate / Annotations versions are you using? If they're rather old it could be a bug in Hibernate code. But I believe it should work if you fix (1) and (2) above.