网友您好, 请在下方输入框内输入要搜索的题目:

题目内容 (请给出正确答案)

DEPARTMENT 表包含以下列: DEPT_ID NUMBER, Primary Key DEPT_ABBR VARCHAR2(4) DEPT_NAME VARCHAR2(30) MGR_ID NUMBER EMPLOYEE 表包含以下列: EMPLOYEE_ID NUMBER EMP_LNAME VARCHAR2(25) EMP_FNAME VARCHAR2(25) DEPT_ID NUMBER JOB_ID NUMBER MGR_ID NUMBER SALARY NUMBER(9,2) HIRE_DATE DATE 请评估以下语句: ALTER TABLE employee ADD CONSTRAINT REFERENTIAL (mgr_id) TO department(mgr_id); 是以下哪个说法()

  • A、ALTER TABLE语句创建从EMPLOYEE表到DEPARTMENT表的引用约束条件
  • B、ALTER TABLE语句创建从DEPARTMENT表到EMPLOYEE表的引用约束条件
  • C、ADD CONSTRAINT子句存在语法错误,因此ALTER TABLE语句将会失败
  • D、ALTER TABLE语句执行成功,但不重新创建引用约束条件

参考答案

更多 “DEPARTMENT 表包含以下列: DEPT_ID NUMBER, Primary Key DEPT_ABBR VARCHAR2(4) DEPT_NAME VARCHAR2(30) MGR_ID NUMBER EMPLOYEE 表包含以下列: EMPLOYEE_ID NUMBER EMP_LNAME VARCHAR2(25) EMP_FNAME VARCHAR2(25) DEPT_ID NUMBER JOB_ID NUMBER MGR_ID NUMBER SALARY NUMBER(9,2) HIRE_DATE DATE 请评估以下语句: ALTER TABLE employee ADD CONSTRAINT REFERENTIAL (mgr_id) TO department(mgr_id); 是以下哪个说法()A、ALTER TABLE语句创建从EMPLOYEE表到DEPARTMENT表的引用约束条件B、ALTER TABLE语句创建从DEPARTMENT表到EMPLOYEE表的引用约束条件C、ADD CONSTRAINT子句存在语法错误,因此ALTER TABLE语句将会失败D、ALTER TABLE语句执行成功,但不重新创建引用约束条件” 相关考题
考题 在执行语句SELECT department_id FROM employees,departments WHERE employees.department_id= departments.department_id;时报错,原因是()。 A.没有给表employees和表departments加别名B.没有给列department_id加别名C.不能用employees.department_id=departments.department_id作为条件D.SELECT后面的department_id没有指定是哪个表

考题 《中国食物成分表2002》中包含食物以包装食品为主。( )

考题 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

考题 请在下列算法的横线上填入适当的语句。以ha和hb为头指针的单链表分别表示有序表A和B,本算法判别表A是否包含在表B内,若是,则返回“true”,否则返回“false”。

考题 工作薄、工作表、单元格的关系是()。 A.工作薄包含单元格,单元格包含工作表B.工作薄包含工作表,工作表包含单元格C.工作表包含工作薄,工作薄包含单元格D.工作表包含单元格,单元格包含工作薄

考题 Examine the description of the EMPLOYEES table:EMP_ID NUMBER(4) NOT NULLLAST_NAME VARCHAR2(30) NOT NULLFIRST_NAME VARCHAR2(30)DEPT_ID NUMBER(2)JOB_CAT VARCHARD2(30)SALARY NUMBER(8,2)Which statement shows the maximum salary paid in each job category of each department? ()A. SELECT dept_id, job_cat, MAX(salary) FROM employees WHERE salary MAX (salary);B. SELECT dept_id, job_cat, MAX(salary) FROM employees GROUP BY dept_id,job_cat;C. SELECT dept_id, job_cat, MAX(salary) FROM employees;D. SELECT dept_id, job_cat, MAX(salary) FROM employees GROUP BY dept_id;E. SELECT dept_id, job_cat, MAX(salary) FROM employees GROUP BY dept _ id job _ cat salary;

考题 Examine the data from the EMP table:EMP_ID DEPT_ID COMMISSION1 10 5002 20 10003 104 10 6005 30 8006 30 2007 108 20 300The COMMISSION column shows the monthly commission earned by the employee. Which three tasks would require subqueries or joins in order to perform in a single step? ()A. Deleting the records of employees who do not earn commission.B. Increasing the commission of employee 3 by the average commission earned in department 20.C. Finding the number of employees who do NOT earn commission and are working for department 20.D. Inserting into the table a new employee 10 who works for department 20 and earns a commission that is equal to the commission earned by employee 3.E. Creating a table called COMMISSION that has the same structure and data as the columns EMP_ID and COMMISSIONS of the EMP table.F. Decreasing the commission by 150 for the employees who are working in department 30 and earning a commission of more then 800.

考题 Examine the data in the EMPLOYEES and DEPARTMENTS tables:EMPLOYEESEMP_NAME 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 6500DEPARTMENTSDEPARTMENT_ID DEPARTMENT_NAME10 Admin20 Education30 IT40 Human ResourcesAlso examine the SQL statements that create the EMPLOYEES and DEPARTMENTS tables:CREATE TABLE departments(department_id NUMBER PRIMARY KEY,department _ name VARCHAR2(30));CREATE TABLE employees(EMPLOYEE_ID NUMBER PRIMARY KEY,EMP_NAME VARCHAR2(20),DEPT_ID NUMBER REFERENCESdepartments(department_id),MGR_ID NUMBER REFERENCESemployees(employee id),MGR_ID NUMBER REFERENCESemployees(employee id),JOB_ID VARCHAR2(15).SALARY NUMBER);ON the EMPLOYEES,On the EMPLOYEES table, EMPLOYEE_ID is the primary key.MGR_ID is the ID of managers and refers to the EMPLOYEE_ID. DEPT_ID is foreign key to DEPARTMENT_ID column of the DEPARTMENTS table. On the DEPARTMENTS table, DEPARTMENT_ID is the primary key.Examine this DELETE statement:DELETEFROM departmentsWHERE department id = 40;What happens when you execute the DELETE statement?()

考题 设在SC(Sno,Cno,Grade)表上定义了触发器:  CREATE TRIGGER tri1 ON SC AFTER INSERT …  当执行语句:INSERT INTO SC VALUES(’s001’, ’c01’,90)  会引发该触发器执行。下列关于触发器执行时表中数据的说法,正确的是()。ASC表和INSERTED表中均包含新插入的数据BSC表和INSERTED表中均不包含新插入的数据CSC表中包含新插入的数据,INSERTED表中不包含新插入的数据DSC表中不包含新插入的数据,INSERTED表中包含新插入的数据

考题 在Access中,空数据库中()A、只包含表,且表中没有数据B、只包含“表”,不包含其他数据库对象C、包含表、查询和窗体,不包含宏和模块D、不包含任何数据库对象

考题 通过创建“雇员”表和“部门”表的视图来显示每个部门的薪金信息。 执行以下语句时会发生什么情况() CREATE OR REPLACE VIEW sal_dept AS SELECT SUM(e.salary) sal, d.department_name FROM employees e, departments d WHERE e.department_id = d.department_id GROUP BY d.department_name ORDER BY d.department_name.A、创建一个复杂视图,返回按部门名称排序的每个部门的薪金总和B、创建一个简单视图,返回按部门名称排序的每个部门的薪金总和C、创建一个复杂视图,返回按部门标识排序的每个部门的薪金总和D、不创建任何视图,因为该语句包含错误,该语句将失败

考题 以颜料为混色基础的显色系,包含的表色系有哪些?

考题 在执行语句SELECT department_id FROM employees,departments WHERE employees.department_id= departments.department_id;时报错,原因是()。A、没有给表employees和表departments加别名B、没有给列department_id加别名C、不能用employees.department_id=departments.department_id作为条件D、SELECT后面的department_id没有指定是哪个表

考题 “雇员”表包含以下列: EMPLOYEE_ID NOT NULL, Primary Key SSNUM NOT NULL, Unique LAST_NAME VARCHAR2(25) FIRST_NAME VARCHAR2(25) DEPARTMENT_ID NUMBER 部门表中 DEPARTMENT_ID 列的外键 SALARY NUMBER(8,2) 如果执行以下语句: CREATE INDEX emp_name_idx ON employees(last_name, first_name); 以下哪个说法是的()A、此语句会创建一个基于函数的索引B、因为语法错误,此语句将失败C、该语句将创建一个组合唯一索引D、该语句将创建一个组合非唯一索引

考题 标准的GRE头中必选字段包括有()A、CheckSumB、Protocl TypeC、Key FieldD、Sequence Numbe

考题 修改表Department添加列Leader数据类型varchar2(10)的语句是:Alter table Department add Leader varchar2(10);

考题 Examine the data in the EMPLOYEES and DEPARTMENTS tables: EMPLOYEES EMP_NAME DEPT_ID MGR_ID JOB_ID SALARY EMPLOYEE_ID 101 Smith 20 120 SA_REP 4000 102 Martin 10 105 CLERK 2500 103 Chris 20 120 IT_ADMIN 4200 104 John 30 108 HR_CLERK 2500 105 Diana 30 108 IT_ADMIN 5000 106 Smith 40 110 AD_ASST 3000 108 Jennifer 30 110 HR_DIR 6500 110 Bob 40 EX_DIR 8000 120 Ravi 20 110 SA*DIR 6500 DEPARTMENTS DEPARTMENT_ID DEPARTMENT_NAME 10 Admin 20 Education 30 IT 40 Human Resources Also examine the SQL statements that create the EMPLOYEES and DEPARTMENTS tables: CREATE TABLE departments (department_id NUMBER PRIMARY KEY, department _ name VARCHAR2(30)); CREATE TABLE employees (EMPLOYEE_ID NUMBER PRIMARY KEY, EMP_NAME VARCHAR2(20), DEPT_ID NUMBER REFERENCES departments(department_id), MGR_ID NUMBER REFERENCES employees(employee id), MGR_ID NUMBER REFERENCES employees(employee id), JOB_ID VARCHAR2(15). SALARY NUMBER); ON the EMPLOYEES, On the EMPLOYEES table, EMPLOYEE_ID is the primary key. MGR_ID is the ID of managers and refers to the EMPLOYEE_ID. DEPT_ID is foreign key to DEPARTMENT_ID column of the DEPARTMENTS table. On the DEPARTMENTS table, DEPARTMENT_ID is the primary key. Examine this DELETE statement: DELETE FROM departments WHERE department id = 40; What happens when you execute the DELETE statement?()A、Only the row with department ID 40 is deleted in the DEPARTMENTS table.B、The statement fails because there are child records in the EMPLOYEES table with department ID 40.C、The row with department ID 40 is deleted in the DEPARTMENTS table. Also the rows with employee IDs 110 and 106 are deleted from the EMPLOYEES table.D、The row with department ID 40 is deleted in the DEPARTMENTS table. Also the rows with employee IDs 106 and 110 and the employees working under employee 110 are deleted from the EMPLOYEES table.E、The row with department ID 40 is deleted in the DEPARTMENTS table. Also all the rows in the EMPLOYEES table are deleted.F、The statement fails because there are no columns specifies in the DELETE clause of the DELETE statement.

考题 多选题Examine the data from the EMP table: EMP_ID DEPT_ID COMMISSION 1 10 500 2 20 1000 3 10 4 10 600 5 30 800 6 30 200 7 10 8 20 300 The COMMISSION column shows the monthly commission earned by the employee. Which three tasks would require subqueries or joins in order to perform in a single step? ()ADeleting the records of employees who do not earn commission.BIncreasing the commission of employee 3 by the average commission earned in department 20.CFinding the number of employees who do NOT earn commission and are working for department 20.DInserting into the table a new employee 10 who works for department 20 and earns a commission that is equal to the commission earned by employee 3.ECreating a table called COMMISSION that has the same structure and data as the columns EMP_ID and COMMISSIONS of the EMP table.FDecreasing the commission by 150 for the employees who are working in department 30 and earning a commission of more then 800.

考题 单选题Examine the description of the EMPLOYEES table: EMP_ID NUMBER(4) NOT NULL LAST_ NAME VARCHAR2(30) NOT NULL FIRST_NAME VARCHAR2(30) DEPT_ID NUMBER(2) JOB_CAT VARCHAR2(30) SALARY NUMBER(8,2) Which statement shows the department ID, minimum salary, and maximum salary paid in that department, only if the minimum salary is less than 5000 and maximum salary is more than 15000?()A SELECT dept_id, MIN(salary), MAX(salary) FROM employees WHERE MIN(salary) 5000 AND MAX(salary) 15000;B SELECT dept_id, MIN(salary), MAX(salary) FROM employees WHERE MIN(salary) 5000 AND MAX(salary) 15000 GROUP BY dept_id;C SELECT dept_id, MIN(salary), MAX(salary) FROM employees HAVING MIN(salary) 5000 AND MAX(salary) 15000;D SELECT dept_id, MIN(salary), MAX(salary) FROM employees GROUP BY dept_id HAVING MIN(salary) 5000 AND MAX(salary) 15000;E SELECT dept_id, MIN(salary), MAX(salary) FROM employees GROUP BY dept_id, salary HAVING MIN(salary) 5000 AND MAX(salary) 15000;

考题 单选题船上的船员属于三个部门:甲板部、轮机部和事务部。()A Seamen on board the ship are in two departments: Deck Department, Engine Department.B Seaman on board the ship are in two department: Deck Department, Engine Department and Service Department.C The Deck Department and the Engine Department are the two departments.D Seamen on board the ship are in three departments: the Deck Department, the Engine Department and the Service Department.

考题 单选题Examine the data in the EMPLOYEES and DEPARTMENTS tables: EMPLOYEES EMP_NAME DEPT_ID MGR_ID JOB_ID SALARY EMPLOYEE_ID 101 Smith 20 120 SA_REP 4000 102 Martin 10 105 CLERK 2500 103 Chris 20 120 IT_ADMIN 4200 104 John 30 108 HR_CLERK 2500 105 Diana 30 108 IT_ADMIN 5000 106 Smith 40 110 AD_ASST 3000 108 Jennifer 30 110 HR_DIR 6500 110 Bob 40 EX_DIR 8000 120 Ravi 20 110 SA*DIR 6500 DEPARTMENTS DEPARTMENT_ID DEPARTMENT_NAME 10 Admin 20 Education 30 IT 40 Human Resources Also examine the SQL statements that create the EMPLOYEES and DEPARTMENTS tables: CREATE TABLE departments (department_id NUMBER PRIMARY KEY, department _ name VARCHAR2(30)); CREATE TABLE employees (EMPLOYEE_ID NUMBER PRIMARY KEY, EMP_NAME VARCHAR2(20), DEPT_ID NUMBER REFERENCES departments(department_id), MGR_ID NUMBER REFERENCES employees(employee id), MGR_ID NUMBER REFERENCES employees(employee id), JOB_ID VARCHAR2(15). SALARY NUMBER); ON the EMPLOYEES, On the EMPLOYEES table, EMPLOYEE_ID is the primary key. MGR_ID is the ID of managers and refers to the EMPLOYEE_ID. DEPT_ID is foreign key to DEPARTMENT_ID column of the DEPARTMENTS table. On the DEPARTMENTS table, DEPARTMENT_ID is the primary key. Examine this DELETE statement: DELETE FROM departments WHERE department id = 40; What happens when you execute the DELETE statement?()A Only the row with department ID 40 is deleted in the DEPARTMENTS table.B The statement fails because there are child records in the EMPLOYEES table with department ID 40.C The row with department ID 40 is deleted in the DEPARTMENTS table. Also the rows with employee IDs 110 and 106 are deleted from the EMPLOYEES table.D The row with department ID 40 is deleted in the DEPARTMENTS table. Also the rows with employee IDs 106 and 110 and the employees working under employee 110 are deleted from the EMPLOYEES table.E The row with department ID 40 is deleted in the DEPARTMENTS table. Also all the rows in the EMPLOYEES table are deleted.F The statement fails because there are no columns specifies in the DELETE clause of the DELETE statement.

考题 单选题Evaluate the SQL statement: 1 SELECT a.emp_name, a.sal, a.dept_id, b.maxsal 2 FROM employees a, 3 (SELECT dept_id, MAX(sal) maxsal 4. FROM employees 5 GROUP BY dept_id) b 6 WHERE a.dept_id = b.dept_id 7 AND a. asl b. maxsal; What is the result of the statement?()A The statement produces an error at line 1.B The statement produces an error at line 3.C The statement produces an error at line 6.D The statement returns the employee name, salary, department ID, and maximum salary earned in the department of the employee for all departments that pay less salary then the maximum salary paid in the company.E The statement returns the employee name, salary, department ID, and maximum salary earned in the department of the employee for all employees who earn less than the maximum salary in their department.

考题 单选题Examine the description of the EMPLOYEES table: EMP_ID NUMBER(4) NOT NULL LAST_NAME VARCHAR2(30) NOT NULL FIRST_NAME VARCHAR2(30) DEPT_ID NUMBER(2) Which statement produces the number of different departments that have employees with last name Smith? ()A SELECT COUNT (*) FROM employees WHERE last _name='smith';B SELECT COUNT (dept_id) FROM employees WHERE last _name='smith';C SELECT DISTINCT (COUNT (dept_id) FROM employees WHERE last _name='smith';D SELECT COUNT (DISTINCT dept_id) FROM employees WHERE last _name='smith';E SELECT UNIQE (dept_id) FROM employees WHERE last _name='smith';

考题 单选题DEPARTMENT 表包含以下列: DEPT_ID NUMBER, Primary Key DEPT_ABBR VARCHAR2(4) DEPT_NAME VARCHAR2(30) MGR_ID NUMBER EMPLOYEE 表包含以下列: EMPLOYEE_ID NUMBER EMP_LNAME VARCHAR2(25) EMP_FNAME VARCHAR2(25) DEPT_ID NUMBER JOB_ID NUMBER MGR_ID NUMBER SALARY NUMBER(9,2) HIRE_DATE DATE 请评估以下语句: ALTER TABLE employee ADD CONSTRAINT REFERENTIAL (mgr_id) TO department(mgr_id); 是以下哪个说法()A ALTER TABLE语句创建从EMPLOYEE表到DEPARTMENT表的引用约束条件B ALTER TABLE语句创建从DEPARTMENT表到EMPLOYEE表的引用约束条件C ADD CONSTRAINT子句存在语法错误,因此ALTER TABLE语句将会失败D ALTER TABLE语句执行成功,但不重新创建引用约束条件

考题 判断题《中国食物成分表2002》中包含食物以包装食品为主。A 对B 错

考题 单选题Evaluate the following function code:   CREATE FUNCTION get_dept_avg(dept_id NUMBER) RETURN NUMBER RESULT_CACHE RELIES_ON (EMPLOYEES) IS avgsal NUMBER(6); BEGIN  SELECT AVG(SALARY)INTO avgsal FROM EMPLOYEES   WHERE DEPARTMENT_ID = dept_id; RETURN avgsal; END get_dept_avg;   Which statement is true regarding the above function?()A  The cached result becomes invalid when any structural change is done to the EMPLOYEES table. B  If the function execution results in an unhandled exception,the exception result is also stored in the cache.C  Each time the function is invoked in a different session,the current result in the result cache gets overwritten.D  If the function is invoked with a different parameter value,the existing result in the result cache gets overwritten by the latest value.

考题 单选题Examine the description of the EMPLOYEES table: EMP_ID NUMBER(4) NOT NULL LAST_NAME VARCHAR2(30) NOT NULL FIRST_NAME VARCHAR2(30) DEPT_ID NUMBER(2) JOB_CAT VARCHARD2(30) SALARY NUMBER(8,2) Which statement shows the maximum salary paid in each job category of each department?()A SELECT dept_id, job_cat, MAX(salary) FROM employees WHERE salary MAX (salary);B SELECT dept_id, job_cat, MAX(salary) FROM employees GROUP BY dept_id,job_cat;C SELECT dept_id, job_cat, MAX(salary) FROM employees;D SELECT dept_id, job_cat, MAX(salary) FROM employees GROUP BY dept_id;E SELECT dept_id, job_cat, MAX(salary) FROM employees GROUP BY dept _ id job _ cat salary;

考题 单选题“雇员”表包含以下列: EMPLOYEE_ID NOT NULL, Primary Key SSNUM NOT NULL, Unique LAST_NAME VARCHAR2(25) FIRST_NAME VARCHAR2(25) DEPARTMENT_ID NUMBER 部门表中 DEPARTMENT_ID 列的外键 SALARY NUMBER(8,2) 如果执行以下语句: CREATE INDEX emp_name_idx ON employees(last_name, first_name); 以下哪个说法是的()A 此语句会创建一个基于函数的索引B 因为语法错误,此语句将失败C 该语句将创建一个组合唯一索引D 该语句将创建一个组合非唯一索引