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我已经在MS Access中创建了四个表来描述个人消防设备的允许配置,以用作资产注册的一部分。详情如下:MS Access - 实施参照完整性 - 多表外键约束
TBL_1 : FIRE_CLASSIFICATION
FIELDS : | PK | CLASS |
---------------------------------------
ENTRIES : | 1 | Fire Blanket |
| 2 | Fire Extinguisher |
| 3 | Fire Hose Reel |
TBL_2 : FIRE_TYPE
FIELDS : | PK | TYPE | FK_CLASS |
------------------------------------------------------------
ENTRIES : | 1 | General | Fire Blanket |
| 2 | Carbon Dioxide | Fire Extinguisher |
| 3 | Foam | Fire Extinguisher |
| 4 | Powder ABE | Fire Extinguisher |
| 5 | Powder BE | Fire Extinguisher |
| 6 | Vap. Liquid | Fire Extinguisher |
| 7 | Water | Fire Extinguisher |
| 8 | Wet Chemical | Fire Extinguisher |
| 9 | General | Fire Hose Reel |
TBL_3 : FIRE_SPECIFIC
FIELDS : | PK | SPECIFIC | FK_CLASS |
------------------------------------------------------------
ENTRIES : | 1 | Dimensions | Fire Blanket |
| 2 | Capacity (kg) | Fire Extinguisher |
| 3 | Length (m) | Fire Hose Reel |
TBL_4 : FIRE_OPTIONS
FIELDS : | PK | FK_CLASS | FK_TYPE | FK_SPECIFIC | OPTION |
----------------------------------------------------------------------------------
ENTRIES : | 1 | Fire Extinguisher | Carbon Dioxide | Capacity (kg) | 2.0 |
| 2 | Fire Extinguisher | Carbon Dioxide | Capacity (kg) | 3.5 |
| 3 | Fire Extinguisher | Carbon Dioxide | Capacity (kg) | 5.0 |
| 4 | Fire Extinguisher | Powder ABE | Capacity (kg) | 1.1 |
| 5 | Fire Extinguisher | Powder ABE | Capacity (kg) | 2.1 |
| 6 | Fire Extinguisher | Powder ABE | Capacity (kg) | 2.3 |
| 7 | Fire Extinguisher | Powder ABE | Capacity (kg) | 2.7 |
| 8 | Fire Extinguisher | Powder ABE | Capacity (kg) | 4.5 |
| 9 | Fire Extinguisher | Powder ABE | Capacity (kg) | 9.0 |
| 10 | Fire Hose Reel | General | Length (m) | 12.0 |
... CONTINUED
目前,它可以插入条目,如
| 11 | Fire Hose Reel | Powder ABE | Dimensions | 1200 x 1200 |
到FIRE_OPTIONS表。这种行为是非常不可取的,因为此条目不符合其他表中指定的声明(允许)组合。
我想了解如何在FIRE_OPTIONS表上实现适当的约束,以便每当指定的条目与其他三个表不一致时就会生成错误。
我试过使用“数据库工具” - “关系”功能,但是我无法同时在TBL_4与TBL_1,TBL_2和TBL_3之间执行“引用完整性”。
我将不胜感激在这个问题上的任何帮助。
**编辑
我能够通过修改主键定义来解决这个问题。这将在下面详细介绍:
TBL_1 : FIRE_CLASSIFICATION
PK: PK (Auto Increment)
TBL_2 : FIRE_TYPE
PK: PK (Auto Increment) & FK_CLASS
TBL_3 : FIRE_SPECIFIC
PK: PK (Auto Increment) & FK_CLASS
TBL_4 : FIRE_OPTIONS
PK: PK (Auto Increment)
然后我定义了以下关系的“数据库工具”中 - “关系”的特点:
[ERI] FIRE_CLASSIFICATION.PK (1) -> FIRE_TYPE.FK_CLASS (MANY)
[ERI] FIRE_CLASSIFICATION.PK (1) -> FIRE_SPECIFIC.FK_CLASS (MANY)
[ERI] { FIRE_CLASSIFICATION.PK (1) -> FIRE_OPTIONS.FK_CLASS (MANY)
FIRE_TYPE.PK (1) -> FIRE_OPTIONS.FK_TYPE (MANY)
FIRE_TYPE.FK_CLASS (1) -> FIRE_OPTIONS.FK_CLASS (MANY)
FIRE_SPECIFIC.PK (1) -> FIRE_OPTIONS.FK_SPECIFIC (MANY)
FIRE_SPECIFIC.FK_CLASS (1) -> FIRE_OPTIONS.FK_CLASS (MANY) }
ERI : "Enforce Referential Integrity" Option Selected