我正在生产数据库的一部分。该业务部门接受自定义订单，并构建符合规格的项目。他们只构建几种（假设3-10种）对象，但是每种对象的记录规格不同。我想要一个主制造表（mfgorders），其中列出了一些常见的字段，然后让它引用特定于所订购实体的规格表。我并不完全相信这是正确的方法。实际上，我一点都不自信。我所有其他建模都非常简单，但是这困扰着我。

这是SQL：

CREATE TABLE dbo.mfgorders (MfgOrderId int NOT NULL
                                       IDENTITY (1, 1) ,
                        OrderId int NOT NULL,
                        LineNbr tinyint NOT NULL,
                        MfgTypeId tinyint NOT NULL,
                        ItemDescription varchar (999) ,
                        ManufacturingCost smallmoney,
                        CONSTRAINT PK_mfgorders PRIMARY KEY (MfgOrderId)) ;
--OrderId + LineNbr are a composite referencing a row on a lineitem table (not depicted here)

CREATE TABLE dbo.mfgorders_entity1 (MfgOrderId int NOT NULL,
                                EntitySize decimal (5, 3) ,
                                Width decimal (4, 2) ,
                                Thickness decimal (4, 2) ,
                                CONSTRAINT PK_mfgorders_entity1 PRIMARY KEY (MfgOrderId)) ;

CREATE TABLE dbo.mfgorders_entity2 (MfgOrderId int NOT NULL,
                                Height decimal (5, 2) ,
                                Width decimal (5, 2) ,
                                Thickness decimal (4, 2) ,
                                RotationSetting decimal (4, 1) ,
                                FinishedHeight decimal (5, 2) ,
                                FinishedWidth decimal (5, 2) ,
                                FinishedThickness decimal (4, 2) ,
                                CONSTRAINT PK_mfgorders_entity2 PRIMARY KEY (MfgOrderId)) ;

CREATE TABLE mfg_types (MfgTypeId tinyint NOT NULL,
                    ItemName varchar (32) NOT NULL,
                    ItemDescription nvarchar (64) NULL,
                    IsActive bit NOT NULL
                                 CONSTRAINT DF_mfg_types_IsActive DEFAULT 1,
                    SortOrder int NULL,
                    CONSTRAINT PK_mfg_types PRIMARY KEY (MfgTypeId)) ;

ALTER TABLE dbo.mfgorders_entity1 ADD CONSTRAINT FK_mfgorders_entity1_mfgorders FOREIGN KEY (MfgOrderId) REFERENCES dbo.mfgorders (MfgOrderId) ON UPDATE NO ACTION ON DELETE CASCADE;

ALTER TABLE dbo.mfgorders_entity2 ADD CONSTRAINT FK_mfgorders_entity2_mfgorders FOREIGN KEY (MfgOrderId) REFERENCES dbo.mfgorders (MfgOrderId) ON UPDATE NO ACTION ON DELETE CASCADE;

ALTER TABLE dbo.mfgorders ADD CONSTRAINT FK_mfgorders_mfg_types FOREIGN KEY (MfgTypeId) REFERENCES dbo.mfg_types (MfgTypeId) ON UPDATE NO ACTION ON DELETE CASCADE;

该模型暗示一个entity1和entity2可以具有相同的MfgOrderId，我当然不希望这样。我希望MfgOrderId仅引用实体之一。我认为我希望利用mfg_types指向正确的实体表，但是我觉得该模型已关闭，我会向SO社区咨询，以增加自己的生活几年。

问候，约翰