您遇到的问题是第四范式。
这是解决方案:
Table RowSubType: RowSubTypeID
FK_RowTypeID
UNIQUE(FK_RowTypeID, RowSubTypeID)
Table ColumnDef: ColumnDefID
FK_RowTypeID
UNIQUE(ColumnDefID, FK_RowTypeID)
Table ColumnDefSubType: FK_ColumnDefID } compound foreign key to ColumnDef
FK_RowTypeID } }
FK_RowSubTypeID } compound foreign key to RowSubType
您只需在 ColumnDefSubType 表中为具有行子类型的列创建一行。但是所有引用都受到限制,因此您无法创建异常。
But for what it's worth, I agree with @Seth's comment about possible over-engineering. I'm not sure I understand how you're using these column defs and row types, but it smells like the Inner-Platform Effect anti-pattern. In SQL, just use metadata to define metadata. Don't try to use data to create a dynamic schema.
See also this excellent story: Bad CaRMa.
Re your comment: In your case I'd recommend using Class Table Inheritance or Concrete Table Inheritance. This means defining a separate table per subtype. But each column of your original text record would go into the respective column of the subtype table. That way you don't need to have your rowtype or rowsubtype tables, it's implicit by defining tables for each subtype. And you don't need your columndefs table, that's implicit by the columns defined in your tables.
See also my answer to Product table, many kinds of product, each product has many parameters or my presentation slides Practical Object-Oriented Models in SQL.