不可能，也许永远不可能，将外键分配给json属性。对PostgreSQL的外键执行来说，这将是一个重大且非常复杂的变化。我认为这并非不可能，但是会遇到与外键到数组补丁所遇到的问题类似的问题。

It is not possible, and may not ever be possible, to assign a foreign key to a json property. It'd be a major and quite complicated change to PostgreSQL's foreign key enforcement. I don't think it's impossible to do, but would face similar issues to those experienced by the foreign-keys-to-arrays patch.

对于9.4，它将是可能使整个json对象成为外键，因为 jsonb 支持相等性测试。在9.3中，您甚至无法做到这一点。

With 9.4 it'll be possible to make a whole json object a foreign key as jsonb supports equality tests. In 9.3 you can't even do that.