關係在ER圖

Question

我試圖創建一家軟件開發公司的數據庫（如自由時間的項目）

我一直在掙扎與此相當長一段時間，它的時間來問你們的幫幫我。

我有3個實體，PROGRAMMER，PROGRAM和PLATFORM。程序員可以在很多平臺上工作，程序可以在很多平臺上工作，程序員可以在很多程序上工作。但是對於特定的程序，程序員只能在一個平臺上工作。所以我創建了另一個名爲WORKS的女巫，它具有以下屬性：Programmer_ID，Program_ID和Platform_ID。前兩個是主鍵，以符合上述規格。

現在，問題是從哪裏開始的：程序員可以監督一個程序（這不是強制性的）。監督小組會議和數據庫必須存儲每個計劃的team_ID和會議日期，也是Meeting_ID，但這是無關緊要的。

因此，我必須創建一個表，不允許重複對Programmer_ID - Program_ID，這樣同一個人不會再次在同一個組上，也必須有一個Team_ID女巫將是與Program_ID的編號相同，並且必須將Team_ID引用到MEETING表，以便我可以存儲它。我怎麼能做這樣的事情？

謝謝你的時間。

PS：這是我ER的外觀：ER Diagram

而且這是在MS SQL 2012導出的DLL：

CREATE 
    TABLE CUSTOMER 
    (
    Customer_ID NUMERIC (5) NOT NULL , 
    Name  CHAR (30) NOT NULL , 
    PR_Guy  CHAR (30) NOT NULL , 
    Phone  CHAR (20) NOT NULL 
) 
    ON "default" 
GO 
ALTER TABLE CUSTOMER ADD CONSTRAINT CUSTOMER_PK PRIMARY KEY CLUSTERED (
Customer_ID) 
WITH 
    (
    ALLOW_PAGE_LOCKS = ON , 
    ALLOW_ROW_LOCKS = ON 
) 
    ON "default" 
GO 

CREATE 
    TABLE KNOWS 
    (
    Programmer_ID NUMERIC (5) NOT NULL , 
    Prog_Lang_ID NUMERIC (3) NOT NULL 
) 
    ON "default" 
GO 
ALTER TABLE KNOWS ADD CONSTRAINT KNOWS_PK PRIMARY KEY CLUSTERED (Programmer_ID, 
Prog_Lang_ID) 
WITH 
    (
    ALLOW_PAGE_LOCKS = ON , 
    ALLOW_ROW_LOCKS = ON 
) 
    ON "default" 
GO 

CREATE 
    TABLE MEETING_DATE 
    (
    Meeting_ID NUMERIC (3) NOT NULL , 
        DATE DATE , 
    Program_ID NUMERIC (5) , 
    Programmer_ID NUMERIC (5) 
) 
    ON "default" 
GO 
ALTER TABLE MEETING_DATE ADD CONSTRAINT MEETING_DATE_PK PRIMARY KEY CLUSTERED (
Meeting_ID) 
WITH 
    (
    ALLOW_PAGE_LOCKS = ON , 
    ALLOW_ROW_LOCKS = ON 
) 
    ON "default" 
GO 

CREATE 
    TABLE PLATFORM 
    (
    Platform_ID NUMERIC (5) NOT NULL , 
    Name   CHAR (30) NOT NULL , 
    OS   CHAR (30) , 
    Latest_Update DATE NOT NULL , 
    Dev_Name  CHAR (30) NOT NULL 
) 
    ON "default" 
GO 
ALTER TABLE PLATFORM ADD CONSTRAINT PLATFORM_PK PRIMARY KEY CLUSTERED (
Platform_ID) 
WITH 
    (
    ALLOW_PAGE_LOCKS = ON , 
    ALLOW_ROW_LOCKS = ON 
) 
    ON "default" 
GO 

CREATE 
    TABLE PROGRAM 
    (
    Program_ID NUMERIC (5) NOT NULL , 
    Name  CHAR (30) NOT NULL , 
    Deadline DATE NOT NULL , 
    Customer_ID NUMERIC (5) NOT NULL 
) 
    ON "default" 
GO 
ALTER TABLE PROGRAM ADD CONSTRAINT PROGRAM_PK PRIMARY KEY CLUSTERED (Program_ID 
) 
WITH 
    (
    ALLOW_PAGE_LOCKS = ON , 
    ALLOW_ROW_LOCKS = ON 
) 
    ON "default" 
GO 

CREATE 
    TABLE PROGRAMMER 
    (
    Programmer_ID NUMERIC (5) NOT NULL , 
    First_Name CHAR (30) NOT NULL , 
    Last_Name  CHAR (30) NOT NULL , 
    Money_Status NUMERIC (1) NOT NULL 
) 
    ON "default" 
GO 
ALTER TABLE PROGRAMMER ADD CONSTRAINT PROGRAMMER_PK PRIMARY KEY CLUSTERED (
Programmer_ID) 
WITH 
    (
    ALLOW_PAGE_LOCKS = ON , 
    ALLOW_ROW_LOCKS = ON 
) 
    ON "default" 
GO 

CREATE 
    TABLE PROG_LANG 
    (
    Prog_Lang_ID NUMERIC (3) NOT NULL , 
    Name   CHAR (30) NOT NULL 
) 
    ON "default" 
GO 
ALTER TABLE PROG_LANG ADD CONSTRAINT PROG_LANG_PK PRIMARY KEY CLUSTERED (
Prog_Lang_ID) 
WITH 
    (
    ALLOW_PAGE_LOCKS = ON , 
    ALLOW_ROW_LOCKS = ON 
) 
    ON "default" 
GO 

CREATE 
    TABLE SUPERVISE 
    (
    Programmer_ID NUMERIC (5) NOT NULL , 
    Program_ID NUMERIC (5) NOT NULL , 
    Group_ID  NUMERIC (5) NOT NULL 
) 
    ON "default" 
GO 
ALTER TABLE SUPERVISE ADD CONSTRAINT SUPERVISE_PK PRIMARY KEY CLUSTERED (
Program_ID, Programmer_ID) 
WITH 
    (
    ALLOW_PAGE_LOCKS = ON , 
    ALLOW_ROW_LOCKS = ON 
) 
    ON "default" 
GO 

CREATE 
    TABLE WORKS 
    (
    Programmer_ID NUMERIC (5) NOT NULL , 
    Program_ID NUMERIC (5) NOT NULL , 
    Platform_ID NUMERIC (5) NOT NULL 
) 
    ON "default" 
GO 
ALTER TABLE WORKS ADD CONSTRAINT WORKS_PK PRIMARY KEY CLUSTERED (Programmer_ID, 
Program_ID) 
WITH 
    (
    ALLOW_PAGE_LOCKS = ON , 
    ALLOW_ROW_LOCKS = ON 
) 
    ON "default" 
GO 

ALTER TABLE KNOWS 
ADD CONSTRAINT FK_ASS_2 FOREIGN KEY 
(
Programmer_ID 
) 
REFERENCES PROGRAMMER 
(
Programmer_ID 
) 
ON 
DELETE 
    NO ACTION ON 
UPDATE NO ACTION 
GO 

ALTER TABLE KNOWS 
ADD CONSTRAINT FK_ASS_3 FOREIGN KEY 
(
Prog_Lang_ID 
) 
REFERENCES PROG_LANG 
(
Prog_Lang_ID 
) 
ON 
DELETE 
    NO ACTION ON 
UPDATE NO ACTION 
GO 

ALTER TABLE MEETING_DATE 
ADD CONSTRAINT MEETING_DATE_SUPERVISE_FK FOREIGN KEY 
(
Program_ID, 
Programmer_ID 
) 
REFERENCES SUPERVISE 
(
Program_ID , 
Programmer_ID 
) 
ON 
DELETE 
    NO ACTION ON 
UPDATE NO ACTION 
GO 

ALTER TABLE PROGRAM 
ADD CONSTRAINT PROGRAM_CUSTOMER_FK FOREIGN KEY 
(
Customer_ID 
) 
REFERENCES CUSTOMER 
(
Customer_ID 
) 
ON 
DELETE 
    NO ACTION ON 
UPDATE NO ACTION 
GO 

ALTER TABLE SUPERVISE 
ADD CONSTRAINT SUPERVISE_WORKS_FK FOREIGN KEY 
(
Programmer_ID, 
Program_ID 
) 
REFERENCES WORKS 
(
Programmer_ID , 
Program_ID 
) 
ON 
DELETE 
    NO ACTION ON 
UPDATE NO ACTION 
GO 

ALTER TABLE WORKS 
ADD CONSTRAINT WORKS_PLATFORM_FK FOREIGN KEY 
(
Platform_ID 
) 
REFERENCES PLATFORM 
(
Platform_ID 
) 
ON 
DELETE 
    NO ACTION ON 
UPDATE NO ACTION 
GO 

ALTER TABLE WORKS 
ADD CONSTRAINT WORKS_PROGRAMMER_FK FOREIGN KEY 
(
Programmer_ID 
) 
REFERENCES PROGRAMMER 
(
Programmer_ID 
) 
ON 
DELETE 
    NO ACTION ON 
UPDATE NO ACTION 
GO 

ALTER TABLE WORKS 
ADD CONSTRAINT WORKS_PROGRAM_FK FOREIGN KEY 
(
Program_ID 
) 
REFERENCES PROGRAM 
(
Program_ID 
) 
ON 
DELETE 
    NO ACTION ON 
UPDATE NO ACTION 
GO 

Answer 1

無法把這個評論，因爲存在是一個圖像所示。

如果您的WORKS表的主鍵全部爲3，即PROGRAMMER_ID，PROGRAM_ID和PLATFORM_ID，那麼MEETING表可以是WORKS表的一個孩子，我認爲可以解決您的問題。

參見下圖