ActiveRecord中的PostgreSQL jsonb字段belongs_to关联
问题描述：
我可以在belongs_to 关联中使用jsonb 字段作为foreign_key 吗?类似的东西:
Can I use a jsonb field as a foreign_key in a belongs_to association? Something along the lines of:
belongs_to :product, class_name: "Product", foreign_key: "data ->'product_id'"
答
引用只能在列(或列组)之间定义，正如 文档:
References can be defined only between columns (or groups of columns), as it is stated in the documentation:
FOREIGN KEY ( column_name [, ... ] ) REFERENCES reftable [ ( refcolumn[, ... ] ) ]
FOREIGN KEY ( column_name [, ... ] ) REFERENCES reftable [ ( refcolumn [, ... ] ) ]