现有如下两个关系模式：Employees（Eid，Name，DeptNO)Departments（DeptNO，DeptName，TotalNumber)Emp

（2 ）现有如下两个关系模式：

Employees （Eid ， Name ， DeptNO ）

Departments （DeptNO ， DeptName ， TotalNumber ）

Employees 关系模式描述了职工编号、姓名和所在部门编号； Departments 关系模式描述了部门编号、名称和职工总人数。

请 按 SQL Serve r 所采用 的 Tansact — SQ L 语法格式编写实现具有功能的后触发型触发器 ： 每当在Employee s表中插入一行数据时，相应部门的职工总人数就加 1 。（10 分）

已知关系模式R的全部属性集U={A，B，C，D，E，G}及函数依赖集：

F=(AB→C，C→A，BC→D，ACD→B，D→EG，BE→C，CG→BD，CE→AG}求属性集闭包(BD)+

(2) 现有如下两个关系模式：

Employees(Eid，Name，DeptNO)

Departments(DeptNO，DeptName，TotalNumber)

Employees关系模式描述了职工编号、姓名和所在部门编号；Departments关系模式描述了部门编号、名称和职工总

A．

B．

C．

D．

ype RemarksEMPLOYEE_ID NUMBER NOT NULL, Primary KeyEMP_NAME VARCHAR2 (30)JOB_ID VARCHAR2 (20)SALARY NUMBERMGR_ID NUMBER References EMPLOYEE_ID COLUMNDEPARTMENT ID NUMBER Foreign key to DEPARTMENT ID column of the DEPARTMENTS tableDEPARTMENTSColumn name Data type RemarksDEPARTMENT_ID NUMBER NOT NULL, Primary Key DEPARTMENT_NAME VARCHAR2(30)MGR_ID NUMBER References MGR_ID column of the EMPLOYEES tableEvaluate this SQL statement:SELECT employee_id, e.department_id, department_name, salaryFROM employees e, departments dWHERE e. department_id = d.department_id;Which SQL statement is equivalent to the above SQL statement？ （）

A. SELECT employee_id, department_id, department_name, salary FROM employees WHERE department_id IN (SELECT department_id FROM departments);

B. SELECT employee_id, department_id, department_name, salary FROM employees NATURAL JOIN departments;

C. SELECT employee_id, d.department_id, department_name, salary FROM employees e JOIN departments d ON e.department _ id = d. department_id;

D. SELECT employee_id, department_id, department_name, Salary FROM employees JOIN departments USING (e.department_id, d.department_id);

pe RemarksEMPLOYEE_ID NUMBER NOT NULL, Primary KeyEMP_NAME VARCHAR2 (30)JOB_ID VARCHAR2 (20)SALARY NUMBERMGR_ID NUMBER References EMPLOYEE_ID COLUMNDEPARTMENT ID NUMBER Foreign key to DEPARTMENT IDcolumn of the DEPARTMENTS tableDEPARTMENTSColumn name Data type RemarksDEPARTMENT_ID NUMBER NOT NULL, Primary KeyDEPARTMENT_NAME VARCHAR2(30)MGR_ID NUMBER References MGR_ID column of theEMPLOYEES tableEvaluate this SQL statement:SELECT employee_id, e.department_id, department_name,salaryFROM employees e, departments dWHERE e. department_id = d.department_id;Which SQL statement is equivalent to the above SQL statement？（）

A. SELECT employee_id, department_id, department_name, salary FROM employees WHERE department_id IN (SELECT department_id FROM departments);

B. SELECT employee_id, department_id, department_name, salary FROM employees NATURAL JOIN departments;

C. SELECT employee_id, d.department_id, department_name, salary FROM employees e JOIN departments d ON e.department _ id = d. department_id;

D. SELECT employee_id, department_id, department_name, Salary FROM employees JOIN departments USING (e.department_id, d.department_id);

● 部门DEPT(Deptno, Name, Tel, Leader) 和职工EMP(Empno, Name, Sex, Address, Deptno) 实体集，若一个职工只能属于一个部门，部门负责人 Leader 是一个职工。关系DEPT和EMP的外码分别为 （30） ；下图中a、b处的实体名分别为 （31） 。

（30）

A. Deptno、Empno

B. Name、 Deptno

C. Leader、Deptno

D. Name、 Address

（31）

A. DEPT、Empno

B. DEPT、EMP

C. EMP、Deptno

D. EMP、DEPT

A.to find the tax percentage for each of the employees

B.to list the name, job_id, and manager name for all the employees

C.to find the name, salary, and the department name of employees who are not working with Smith

D.to find the number of employees working for the Administrative department and earning less than 4000

E.to display name, salary, manager ID, and department name of all the employees, even if the employees do not have a department ID assigned

● 部门DEPT(Deptno, Name, Tel, Leader) 和职工EMP(Empno, Name, Sex, Address, Deptno) 实体集，若一个职工只能属于一个部门，部门负责人 Leader 是一个职工。关系DEPT和EMP的外码分别为 （30） ；下图中a、b处的实体名分别为 （31） 。

（30）

A. Deptno、Empno

B. Name、 Deptno

C. Leader、Deptno

D. Name、 Address

（31）

A. DEPT、Empno

B. DEPT、EMP

C. EMP、Deptno

D. EMP、DEPT