Given the following tables: CONTINENTS ID NAME COUNTRIES1 Antarctica 02 Africa 533 Asia 474 Australia 145 Europe 436 North America 237 South America 12REGION ID LOCATION 1 East 2 WestHow many rows would be returned using the following statement? SELECT lo

题目

Given the following tables: CONTINENTS ID NAME COUNTRIES1 Antarctica 02 Africa 533 Asia 474 Australia 145 Europe 436 North America 237 South America 12REGION ID LOCATION 1 East 2 WestHow many rows would be returned using the following statement? SELECT location FROM continents, region（）

A.2

B.7

C.9

D.14

相似考题

1.学生表(id,name,sex,age,depart_id,depart_name),存在的函数依赖是id→{name,sex,age,depart_id};dept_id→dept_name,其满足()、A、1NFB、2NFC、3NFD、4NF

2.You created a view called EMP_DEPT_VU that contains three columns from the EMPLOYEES and DEPARTMENTS tables:EMPLOYEE_ID, EMPLOYEE_NAME AND DEPARTMENT_NAME.The DEPARTMENT_ID column of the EMPLOYEES table is the foreign key to the primary keyDEPARTMENT_ID column of the DEPARTMENTS table.You want to modify the view by adding a fourth column, MANAGER_ID of NUMBER data type from the EMPLOYEES tables.How can you accomplish this task? （）A. ALTER VIEW EMP_dept_vu (ADD manger_id NUMBER);B. MODIFY VIEW EMP_dept_vu (ADD manger_id NUMBER);C. ALTER VIEW emp_dept_vu AS SELECT employee_id, employee_name, department_name, manager_id FROM employee e, departments d WHERE e.department _ id = d.department_id;D. MODIFY VIEW emp_dept_vu AS SELECT employee_id, employee_name, department_name, manager_id FROM employees e, departments d WHERE e.department _ id = d.department_id;E. CREATE OR REPLACE VIEW emp_dept_vu AS SELECT employee_id, employee_name, department_name, manager_id FROM employees e, departments d WHERE e.department _ id = d.department_id;F. You must remove the existing view first, and then run the CREATE VIEW command with a new column list to modify a view.

3.Examine the structure of the EMPLOYEES and DEPARTMENTS tables: EMPLOYEESColumn name Data type 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);

4.学生表(id,name,sex,age,depart_id,depart_name),存在函数依赖是id→name,sex,age,depart_id;dept_id→dept_name,其满足()。A、1NFB、2NFC、3NFD、BCNF

参考答案和解析
参考答案：D
更多“Given the following tables: CONTINENTS ID NAME COUNTRIES1 Antarctica 02 Africa 533 Asia 47 ”相关问题

  • 第1题：

    ExhibitExamine the data in the EMPLOYEES and DEPARTMENTS tables.You want to retrieve all employees‘ last names, along with their manager‘s last names and their department names. Which query would you use?（）

    A. SELECT last_name, manager_id, department_name FROM employees e FULL OUTER JOIN department d ON (e.department_id = d.department_id);

    B. SELECT e.last_name, m.last_name, department_name FROM employees e LEFT OUTER JOIN employees m on ( e.managaer_id = m.employee_id) LEFT OUTER JOIN department d ON (e.department_id = d.department_id);

    C. SELECT e.last_name, m.last_name, department_name FROM employees e RIGT OUTER JOIN employees m on ( e.manager_id = m.employee_id) FULL OUTER JOIN department d ON (e.department_id = d.department_id);

    D. SELECT e.last_name, m.last_name, department_name FROM employees e LEFT OUTER JOIN employees m on ( e.manager_id = m.employee_id) RIGT OUTER JOIN department d ON (e.department_id = d.department_id);

    E. SELECT e.last_name, m.last_name, department_name FROM employees e RIGHT OUTER JOIN employees m on ( e.manager_id = m.employee_id) RIGHT OUTER JOIN departments d ON (e.department_id = d.department_id)

    F. SELECT last_name, manager_id, department_name FROM employees e JOIN department d ON (e.department_id = d.department_id);


    参考答案：B

  • 第2题：

    Examine the data in the EMPLOYEES and EMP_HIST tables:EMPLOYEESNAME DEPT_ID MGR_ID JOB_ID SALARYEMPLOYEE_ID101 Smith 20 120 SA_REP 4000102 Martin 10 105 CLERK 2500103 Chris 20 120 IT_ADMIN 4200104 John 30 108 HR_CLERK 2500105 Diana 30 108 IT_ADMIN 5000106 Smith 40 110 AD_ASST 3000108 Jennifer 30 110 HR_DIR 6500110 Bob 40 EX_DIR 8000120 Ravi 20 110 SA_DIR 6500EMP HISTEMPLOYEE_ID NAME JOB_ID SALARY101 Smith SA_CLERK 2000103 Chris IT_CLERK 2200104 John HR_CLERK 2000106 Smith AD_ASST 3000108 Jennifer HR_MGR 4500The EMP_HIST table is updated at the end of every year. The employee ID, name, job ID, and salary of each existing employee are modified with the latest data. New employee details are added to the table.Which statement accomplishes this task?（）

    A. UPDATE emp_hist SET employee_id, name, job_id, salary = (SELECT employee_id, name, job_id, salary FROM employees) WHERE employee_id IN (SELECT employee_id FROM employees);

    B. MERGE INTO emp_hist eh USING employees e ON (eh.employee_id = e.employee_id) WHEN MATCHED THEN UPDATE SET eh.name = e.name, eh.job_id = e.job_id, eh.salary = e.salary WHEN NOT MATCHED THEN INSERT VALUES (e.employee id, e.name, job id, e.salary);

    C. MERGE INTO emp_hist eh USING employees e ON (eh.employee_id = e.employee_id) WHEN MATCHED THEN UPDATE emp hist SET eh.name = e.name, eh.job_id = e.job_id, eh.salary = e.salary WHEN NOT MATCHED THEN INSERT INTO emp_hist VALUES (e.employees_id, e.name, e.job_id, e.salary);

    D. MERGE INTO emp_hist eh USING employees e WHEN MATCHED THEN UPDATE emp_hist SET eh.name = e.name, eh.job_id = e.job_id, eh.salary = e.salary WHEN NOT MATCHED THEN INSERT INTO emp_hist VALUES (e.employees_id, e.name, e.job_id, e.salary);


    参考答案：B

  • 第3题：

    Given the following two tables:TAB1 C1 C21 Antarctica 2 Africa 3 Asia 4 Australia TAB2 CX CY5 Europe 6 North America 7 South AmericaWhich of the following SQL statements will insert all rows found in table TAB2 into table TAB1?（）

    A.INSERT INTO tab1 SELECT cx, cy FROM tab2

    B.INSERT INTO tab1 VALUES (tab2.cx, tab2.cy)

    C.INSERT INTO tab1 VALUES (SELECT cx, cy FROM tab2)

    D.INSERT INTO tab1 (c1, c2) VALUES (SELECT cx, cy FROM tab2)


    参考答案：A

  • 第4题：

    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;


    参考答案：D

  • 第5题：

    Click the Exhibit button and examine the data in the EMPLOYEES and DEPARTMENTS tables.You want to retrieve all employees‘ last names, along with their managers‘ last names and their department names. Which query would you use?（）

    A.SELECT last_name, manager_id, department_name FROM employees e FULL OUTER JOIN departments d ON (e.department_id = d.department_id);

    B.SELECT e.last_name, m.last_name, department_name FROM employees e LEFT OUTER JOIN employees m on ( e.manager_id = m.employee_id) LEFT OUTER JOIN departments d ON (e.department_id = d.department_id);

    C.SELECT e.last_name, m.last_name, department_name FROM employees e RIGHT OUTER JOIN employees m on ( e.manager_id = m.employee_id) LEFT OUTER JOIN departments d ON (e.department_id = d.department_id);

    D.SELECT e.last_name, m.last_name, department_name FROM employees e LEFT OUTER JOIN employees m on ( e.manager_id = m.employee_id) RIGHT OUTER JOIN departments d ON (e.department_id = d.department_id);

    E.SELECT e.last_name, m.last_name, department_name FROM employees e RIGHT OUTER JOIN employees m on ( e.manager_id = m.employee_id) RIGHT OUTER JOIN departments d ON (e.department_id = d.department_id);

    F.SELECT last_name, manager_id, department_name FROM employees e JOIN departments d ON (e.department_id = d.department_id) ;


    参考答案：B

相关内容