Examine the structure of the EMPLOYEES and DEPARTMENTS tables:EMPLOYEESEMPLOYEE_ID NUMBERDEPARTMENT_ID NUMBERMANAGER_ID NUMBERLAST_NAME VARCHAR2(25)DEPARTMENTSDEPARTMENT_ID NUMBERMANAGER_ID NUMBERDEPARTMENT_NAME VARCHAR2(35)LOCATION_ID NUMBERYou want to c
题目
Examine the structure of the EMPLOYEES and DEPARTMENTS tables:EMPLOYEESEMPLOYEE_ID NUMBERDEPARTMENT_ID NUMBERMANAGER_ID NUMBERLAST_NAME VARCHAR2(25)DEPARTMENTSDEPARTMENT_ID NUMBERMANAGER_ID NUMBERDEPARTMENT_NAME VARCHAR2(35)LOCATION_ID NUMBERYou want to create a report displaying employee last names, department names, and locations. Which query should you use to create an equi-join?（）
A. SELECT last_name, department_name, location_id FROM employees , department ;
B. SELECT employees.last_name, departments.department_name, departments.location_id FROM employees e, departments D WHERE e.department_id = d.department_id;
C. SELECT e.last_name, d.department_name, d.location_id FROM employees e, departments D WHERE manager_id = manager_id;
D. SELECT e.last_name, d.department_name, d.location_id FROM employees e, departments D WHERE e.department_id = d.department_id;
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更多“Examine the structure of the EMPLOYEES and DEPARTMENTS tables:EMPLOYEESEMPLOYEE_ID NUMBERD ”相关问题
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第1题：
（ 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）
正确答案：
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第2题：
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
正确答案：(BD)+=ABCDEG X(O)=BD；由D→EG可知X(1) =BDEG；再由BE→C可知X(2)→BDEGC；又有CG→BDCE→AG可知X(3)=BDEGCA因为X(3)中包含了所有的属性集即有(BD)+=X(3)=ABCDEG T—C(TNO．CNO)主码(TNOCNO)外码TNOCNO S—C(SNOCNO成绩)主码(SNOCNO)．外码SNOCNO (2) create trigger sql_tri on employees for
(BD)+=ABCDEG X(O)=BD；由D→EG可知X(1) =BDEG；再由BE→C，可知X(2)→BDEGC；又有CG→BD，CE→AG，可知X(3)=BDEGCA，因为X(3)中包含了所有的属性集，即有(BD)+=X(3)=ABCDEG T—C(TNO．CNO)主码(TNO，CNO)，外码TNO，CNO S—C(SNO，CNO，成绩)主码(SNO，CNO)．外码SNO，CNO (2) create trigger sql_tri on employees for 解析：本题考查了后触发器的Transact—SQL语句。其语法格式为：
CREATE TRIGGER触发器名称
0N |表名|视图名|
[WITH ENCRYPTION]
AS
SQL语句
AFTER和FOR，指定触发器只有在引发的SQL语句中指定的操作都已成功执行，并且所有的约束检查也成功完成后，才执行此触发器，即后触发型触发器。 -
第3题：
Nothing in these Rules shall ______ any vessel，or the owner，master or crew thereof，from the consequences of any precaution which may be required by the ordinary practice of seaman，or by the special circumstances of the case．
A.exonerate
B.exhaust
C.exercise
D.examine
正确答案：A
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第4题：
After __________ (examine) the lady, the doctor suggested that his back was badly hurt in the accident.参考答案：being examined
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第5题：
检查
A.expect
B.except
C.excuse
D.examine
正确答案：D
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第6题：
He rolled up his trouer leg to exhibit his wounded knee.A:spread
B:open
C:show
D:examine答案：C解析：本句意思：他卷起他的裤腿来显露受伤的膝盖。exhibit展示，显示。spread伸开，展开；open打开；show展示，出示；examine检查。