如果我有包含相同值的行，我应该如何链接主键和外键？

我要创建使用所提供的数据DDL脚本：如果我有包含相同值的行，我应该如何链接主键和外键？

你可以做如下假设：

每个项目都有一个经理
许多员工被分配到每个项目。属性小时数表示每个员工在相应项目上工作的小时数，属性评级是该员工在此项目中的工作评分。
预算和起始日期指的是预算，启动该项目的日期
Emp_Manager是员工的经理，并且可以从项目经理

我已经转变到这些3NF不同：

a. Employee_T(Emp_Id, Emp_Salary, Emp_dept) 
b. Project_T(Proj_Name, Proj_Mgr, Proj_Budget, Start_Date) 
c. EmployeeLine_T(Emp_Id, Proj_Name, Hours, Rating) 
d. EmpMgr_T(Emp_Dept, Emp_Manager)

这是我创建的DDL：

BEGIN 

    --Bye Tables! 
    FOR i IN (SELECT ut.table_name 
       FROM USER_TABLES ut) LOOP 
    EXECUTE IMMEDIATE 'drop table '|| i.table_name ||' CASCADE CONSTRAINTS '; 
    END LOOP; 

END; 

CREATE TABLE PROJECT_T 
(
    Proj_Name  VARCHAR2(25) NOT NULL, 
    Proj_Mgr  VARCHAR2(25), 
    Proj_Budget  NUMBER   NOT NULL, 
    Start_Date  DATE   NOT NULL, 
    CONSTRAINT Proj_Name_PK 
     PRIMARY KEY (Proj_Name) 
); 

INSERT INTO PROJECT_T 
(Proj_Name, Proj_Mgr, Proj_Budget, Start_Date) 
VALUES ('Jupiter','Smith',100000,'15-JAN-2015'); 
INSERT INTO PROJECT_T 
(Proj_Name, Proj_Mgr, Proj_Budget, Start_Date) 
VALUES ('Jupiter','Smith',100000,'15-JAN-2015'); 
INSERT INTO PROJECT_T 
(Proj_Name, Proj_Mgr, Proj_Budget, Start_Date) 
VALUES ('Jupiter','Smith',100000,'15-JAN-2015'); 
INSERT INTO PROJECT_T 
(Proj_Name, Proj_Mgr, Proj_Budget, Start_Date) 
VALUES ('Maxima','Lee',200000,'1-MAR-2014'); 
INSERT INTO PROJECT_T 
(Proj_Name, Proj_Mgr, Proj_Budget, Start_Date) 
VALUES ('Maxima','Lee',200000,'1-MAR-2014'); 
INSERT INTO PROJECT_T 
(Proj_Name, Proj_Mgr, Proj_Budget, Start_Date) 
VALUES ('Maxima','Lee',200000,'1-MAR-2014'); 

CREATE TABLE MANAGERS_T 
(
    Emp_Dept   NUMBER   NOT NULL, 
    Emp_Manager   VARCHAR2(25) NOT NULL, 
    CONSTRAINT Emp_Dept_PK 
     PRIMARY KEY (Emp_Dept) 
); 

INSERT INTO MANAGERS_T 
(Emp_Dept, Emp_Manager) 
VALUES (10,'Levine'); 
INSERT INTO MANAGERS_T 
(Emp_Dept, Emp_Manager) 
VALUES (12,'Jones'); 
INSERT INTO MANAGERS_T 
(Emp_Dept, Emp_Manager) 
VALUES (10,'Levine'); 
INSERT INTO MANAGERS_T 
(Emp_Dept, Emp_Manager) 
VALUES (10,'Levine'); 
INSERT INTO MANAGERS_T 
(Emp_Dept, Emp_Manager) 
VALUES (10,'Levine'); 
INSERT INTO MANAGERS_T 
(Emp_Dept, Emp_Manager) 
VALUES (15,'Jones'); 

CREATE TABLE EMPLOYEE_T 
(
    Emp_Id   VARCHAR2(4)  NOT NULL, 
    Emp_Salary  NUMBER, 
    Emp_Dept  NUMBER   NOT NULL, 
    CONSTRAINT Emp_Id_PK 
     PRIMARY KEY (Emp_Id), 
    CONSTRAINT Emp_Dept_FK 
     FOREIGN KEY (Emp_Dept) REFERENCES MANAGERS_T(Emp_Dept) 
); 

INSERT INTO EMPLOYEE_T 
(Emp_Id,Emp_Salary,Emp_Dept) 
VALUES ('E101',60000,10); 
INSERT INTO EMPLOYEE_T 
(Emp_Id,Emp_Salary,Emp_Dept) 
VALUES ('E105',55000,12); 
INSERT INTO EMPLOYEE_T 
(Emp_Id,Emp_Salary,Emp_Dept) 
VALUES ('E110',43000,10); 
INSERT INTO EMPLOYEE_T 
(Emp_Id,Emp_Salary,Emp_Dept) 
VALUES ('E101',60000,10); 
INSERT INTO EMPLOYEE_T 
(Emp_Id,Emp_Salary,Emp_Dept) 
VALUES ('E110',43000,10); 
INSERT INTO EMPLOYEE_T 
(Emp_Id,Emp_Salary,Emp_Dept) 
VALUES ('E120',45000,10); 

CREATE TABLE EMPLOYEELINE_T 
(
    Emp_Id   VARCHAR(4)  NOT NULL, 
    Proj_Name  VARCHAR2(25) NOT NULL, 
    Hours   NUMBER, 
    Rating   NUMBER, 
    CONSTRAINT EmpID_ProjName_PK 
     PRIMARY KEY(Emp_Id,Proj_Name), 
    CONSTRAINT Proj_Name_FK  
     FOREIGN KEY (Proj_Name) REFERENCES PROJECT_T(Proj_Name), 
    CONSTRAINT Emp_Id_FK  
     FOREIGN KEY (Emp_Id) REFERENCES EMPLOYEE_T(Emp_Id) 
); 

INSERT INTO EMPLOYEELINE_T 
(Emp_Id, Proj_Name, Hours, Rating) 
VALUES ('E101','Jupiter',25,9); 
INSERT INTO EMPLOYEELINE_T 
(Emp_Id, Proj_Name, Hours, Rating) 
VALUES ('E105','Jupiter',40,0); 
INSERT INTO EMPLOYEELINE_T 
(Emp_Id, Proj_Name, Hours, Rating) 
VALUES ('E110','Jupiter',10,8); 
INSERT INTO EMPLOYEELINE_T 
(Emp_Id, Proj_Name, Hours, Rating) 
VALUES ('E101','Maxima',15,0); 
INSERT INTO EMPLOYEELINE_T 
(Emp_Id, Proj_Name, Hours, Rating) 
VALUES ('E110','Maxima',30,0); 
INSERT INTO EMPLOYEELINE_T 
(Emp_Id, Proj_Name, Hours, Rating) 
VALUES ('E120','Maxima',15,0);

Here's a GitHub Link

这是我的表应该如何与他们的主键和外键。当我创建表格时，它们运行良好。问题是我开始向它们中插入值。

我得到像唯一约束违反的错误，因为有重复的值。我会怎么做呢？

来源

2017-10-10 pyuntae

如果你想在更多的行中的DDL表中插入PROJ_NAME你应该创建主要用于至少几个字段 – Frank

的我不明白你是什么意思？ @Frank – pyuntae

研究NORMALIZATION ::该练习要求您删除重复内容，而不是将图像中的数据复制到许多表格中。例如“木星”应该在项目表中出现一次 –

DDL很好，问题在于插入脚本。检查下面的脚本：

BEGIN 

    --Bye Tables! 
    FOR i IN (SELECT ut.table_name 
       FROM USER_TABLES ut) LOOP 
    EXECUTE IMMEDIATE 'drop table '|| i.table_name ||' CASCADE CONSTRAINTS '; 
    END LOOP; 

END; 

CREATE TABLE PROJECT_T 
(
    Proj_Name  VARCHAR2(25) NOT NULL, 
    Proj_Mgr  VARCHAR2(25), 
    Proj_Budget  NUMBER   NOT NULL, 
    Start_Date  DATE   NOT NULL, 
    CONSTRAINT Proj_Name_PK 
     PRIMARY KEY (Proj_Name) 
); 

INSERT INTO PROJECT_T 
(Proj_Name, Proj_Mgr, Proj_Budget, Start_Date) 
VALUES ('Jupiter','Smith',100000,'15-JAN-2015'); 
INSERT INTO PROJECT_T 
(Proj_Name, Proj_Mgr, Proj_Budget, Start_Date) 
VALUES ('Maxima','Lee',200000,'1-MAR-2014'); 

CREATE TABLE MANAGERS_T 
(
    Emp_Dept   NUMBER   NOT NULL, 
    Emp_Manager   VARCHAR2(25) NOT NULL, 
    CONSTRAINT Emp_Dept_PK 
     PRIMARY KEY (Emp_Dept) 
); 

INSERT INTO MANAGERS_T 
(Emp_Dept, Emp_Manager) 
VALUES (10,'Levine'); 
INSERT INTO MANAGERS_T 
(Emp_Dept, Emp_Manager) 
VALUES (12,'Jones'); 
INSERT INTO MANAGERS_T 
(Emp_Dept, Emp_Manager) 
VALUES (15,'Jones'); 

CREATE TABLE EMPLOYEE_T 
(
    Emp_Id   VARCHAR2(4)  NOT NULL, 
    Emp_Salary  NUMBER, 
    Emp_Dept  NUMBER   NOT NULL, 
    CONSTRAINT Emp_Id_PK 
     PRIMARY KEY (Emp_Id), 
    CONSTRAINT Emp_Dept_FK 
     FOREIGN KEY (Emp_Dept) REFERENCES MANAGERS_T(Emp_Dept) 
); 

INSERT INTO EMPLOYEE_T 
(Emp_Id,Emp_Salary,Emp_Dept) 
VALUES ('E101',60000,10); 
INSERT INTO EMPLOYEE_T 
(Emp_Id,Emp_Salary,Emp_Dept) 
VALUES ('E105',55000,12); 
INSERT INTO EMPLOYEE_T 
(Emp_Id,Emp_Salary,Emp_Dept) 
VALUES ('E110',43000,10); 
INSERT INTO EMPLOYEE_T 
(Emp_Id,Emp_Salary,Emp_Dept) 
VALUES ('E120',45000,10); 

CREATE TABLE EMPLOYEELINE_T 
(
    Emp_Id   VARCHAR(4)  NOT NULL, 
    Proj_Name  VARCHAR2(25) NOT NULL, 
    Hours   NUMBER, 
    Rating   NUMBER, 
    CONSTRAINT EmpID_ProjName_PK 
     PRIMARY KEY(Emp_Id,Proj_Name), 
    CONSTRAINT Proj_Name_FK  
     FOREIGN KEY (Proj_Name) REFERENCES PROJECT_T(Proj_Name), 
    CONSTRAINT Emp_Id_FK  
     FOREIGN KEY (Emp_Id) REFERENCES EMPLOYEE_T(Emp_Id) 
); 

INSERT INTO EMPLOYEELINE_T 
(Emp_Id, Proj_Name, Hours, Rating) 
VALUES ('E101','Jupiter',25,9); 
INSERT INTO EMPLOYEELINE_T 
(Emp_Id, Proj_Name, Hours, Rating) 
VALUES ('E105','Jupiter',40,NULL); 
INSERT INTO EMPLOYEELINE_T 
(Emp_Id, Proj_Name, Hours, Rating) 
VALUES ('E110','Jupiter',10,8); 
INSERT INTO EMPLOYEELINE_T 
(Emp_Id, Proj_Name, Hours, Rating) 
VALUES ('E101','Maxima',15,NULL); 
INSERT INTO EMPLOYEELINE_T 
(Emp_Id, Proj_Name, Hours, Rating) 
VALUES ('E110','Maxima',30,NULL); 
INSERT INTO EMPLOYEELINE_T 
(Emp_Id, Proj_Name, Hours, Rating) 
VALUES ('E120','Maxima',15,NULL);

来源

2017-10-10 08:12:09 L30n1d45

我得到像违反唯一约束错误，因为有被重复的值。我会怎么做呢？

不要重复值。

除此之外，管理者是员工：

的Oracle 11g R2架构设置：

CREATE TABLE EMPLOYEE_T 
(
    Emp_Id   VARCHAR2(4)  CONSTRAINT Employee__Emp_Id_PK PRIMARY KEY, 
    Emp_Salary  NUMBER, 
    Emp_Dept  NUMBER   CONSTRAINT Employee__Emp_Dept__NN NOT NULL, 
    Name   VARCHAR2(20) 
); 

CREATE TABLE MANAGERS_T 
(
    Emp_Dept NUMBER  CONSTRAINT Managers__Emp_Dept__PK PRIMARY KEY, 
    Manager_ID VARCHAR2(4) CONSTRAINT Manager__Manager_ID__FK REFERENCES Employee_T (Emp_ID) 
); 

ALTER TABLE Employee_T ADD CONSTRAINT Emp_Dept_FK 
    FOREIGN KEY (Emp_Dept) REFERENCES MANAGERS_T(Emp_Dept); 

INSERT INTO MANAGERS_T (Emp_Dept, Manager_ID) 
SELECT 10,NULL FROM DUAL UNION ALL 
SELECT 12,NULL FROM DUAL UNION ALL 
SELECT 15,NULL FROM DUAL; 

INSERT INTO EMPLOYEE_T (Emp_Id,Emp_Salary,Emp_Dept,Name) 
SELECT 'E101',60000,10,'Alice' FROM DUAL UNION ALL 
SELECT 'E105',55000,12,'Bob' FROM DUAL UNION ALL 
SELECT 'E110',43000,10,'Carol' FROM DUAL UNION ALL 
SELECT 'E120',45000,10,'David' FROM DUAL UNION ALL 
SELECT 'E001',NULL,10,'Smith' FROM DUAL UNION ALL 
SELECT 'E002',NULL,12,'Jones' FROM DUAL UNION ALL 
SELECT 'E003',NULL,10,'Levine' FROM DUAL UNION ALL 
SELECT 'E004',NULL,12,'Lee' FROM DUAL; 

UPDATE MANAGERS_T SET Manager_ID = 'E003' WHERE Emp_Dept = 10; 
UPDATE MANAGERS_T SET Manager_ID = 'E002' WHERE Emp_Dept = 12; 
UPDATE MANAGERS_T SET Manager_ID = 'E001' WHERE Emp_Dept = 15; 

ALTER TABLE Managers_T MODIFY Manager_ID VARCHAR2(4) CONSTRAINT Managers__Manager_ID__NN NOT NULL; 

CREATE TABLE PROJECT_T 
(
    Proj_Name  VARCHAR2(25) CONSTRAINT Proj_Name_PK PRIMARY KEY, 
    Proj_Mgr  VARCHAR2(4)  CONSTRAINT Project__Proj_Mgr__FK REFERENCES Employee_T (Emp_ID), 
    Proj_Budget  NUMBER   CONSTRAINT Project__Budget__NN NOT NULL, 
    Start_Date  DATE   CONSTRAINT Project__Start_Date__NN NOT NULL 
); 

INSERT INTO PROJECT_T (Proj_Name, Proj_Mgr, Proj_Budget, Start_Date) 
SELECT 'Jupiter','E001',100000, DATE '2015-01-15' FROM DUAL UNION ALL 
SELECT 'Maxima','E004',200000,DATE '2014-03-01' FROM DUAL; 

CREATE TABLE EMPLOYEELINE_T 
(
    Emp_Id   VARCHAR(4) CONSTRAINT Emp_Id_FK REFERENCES EMPLOYEE_T(Emp_Id), 
    Proj_Name  VARCHAR2(25) CONSTRAINT Proj_Name_FK REFERENCES PROJECT_T(Proj_Name), 
    Hours   NUMBER, 
    Rating   NUMBER, 
    CONSTRAINT EmpID_ProjName_PK PRIMARY KEY(Emp_Id,Proj_Name) 
); 

INSERT INTO EMPLOYEELINE_T (Emp_Id, Proj_Name, Hours, Rating) 
SELECT 'E101','Jupiter',25,9 FROM DUAL UNION ALL 
SELECT 'E105','Jupiter',40,0 FROM DUAL UNION ALL 
SELECT 'E110','Jupiter',10,8 FROM DUAL UNION ALL 
SELECT 'E101','Maxima',15,0 FROM DUAL UNION ALL 
SELECT 'E110','Maxima',30,0 FROM DUAL UNION ALL 
SELECT 'E120','Maxima',15,0 FROM DUAL;

查询1：

SELECT p.proj_name, 
     p.proj_mgr, 
     el.emp_id, 
     el.hours, 
     p.proj_budget, 
     p.start_date, 
     e.emp_salary, 
     m.manager_id, 
     e.emp_dept, 
     el.rating 
FROM project_t p 
     INNER JOIN Employeeline_t el 
     ON (p.proj_name = el.proj_name) 
     INNER JOIN employee_t e 
     ON (el.emp_id = e.emp_id) 
     INNER JOIN managers_t m 
     ON (e.emp_dept = m.emp_dept)

Results：

| PROJ_NAME | PROJ_MGR | EMP_ID | HOURS | PROJ_BUDGET |   START_DATE | EMP_SALARY | MANAGER_ID | EMP_DEPT | RATING | 
|-----------|----------|--------|-------|-------------|----------------------|------------|------------|----------|--------| 
| Maxima |  E004 | E120 | 15 |  200000 | 2014-03-01T00:00:00Z |  45000 |  E003 |  10 |  0 | 
| Jupiter |  E001 | E110 | 10 |  100000 | 2015-01-15T00:00:00Z |  43000 |  E003 |  10 |  8 | 
| Maxima |  E004 | E110 | 30 |  200000 | 2014-03-01T00:00:00Z |  43000 |  E003 |  10 |  0 | 
| Jupiter |  E001 | E101 | 25 |  100000 | 2015-01-15T00:00:00Z |  60000 |  E003 |  10 |  9 | 
| Maxima |  E004 | E101 | 15 |  200000 | 2014-03-01T00:00:00Z |  60000 |  E003 |  10 |  0 | 
| Jupiter |  E001 | E105 | 40 |  100000 | 2015-01-15T00:00:00Z |  55000 |  E002 |  12 |  0 |

来源

2017-10-10 08:46:11 MT0

经理不是员工。如果他们那么E120和E150将拥有相同的经理人，对吧？ – pyuntae

@pyuntae所有我认识的公司/部门经理的组织都是由公司雇用的，员工也是如此 - 您的数据库应该反映真实的生活。如果您正确建立了表格，E120和E105（或E150）不必具有相同的管理器。 – MT0

如果我有包含相同值的行，我应该如何链接主键和外键？

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