ALTER TABLE dbo.Categories
ADD CONSTRAINT FK_Categories_Self FOREIGN KEY (ParentID)
REFERENCES dbo.Categories (ID)
go
注意,最好将外键设置为"允许空".
ALTER TABLE dbo.Categories
ADD CONSTRAINT FK_Categories_Self FOREIGN KEY (ParentID)
REFERENCES dbo.Categories (ID)
go
注意,最好将外键设置为"允许空".