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?()

题目
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';

参考答案和解析
正确答案: C
解析: 暂无解析
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相似问题和答案

第1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?()


参考答案:B

第2题:

Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) Which three statements inserts a row into the table? ()

  • A、INSERT INTO employees VALUES (NULL, 'JOHN','Smith');
  • B、INSERT INTO employees( first_name, last_name) VALUES ('JOHN','Smith');
  • C、INSERT INTO employees VALUES ('1000','JOHN','NULL');
  • D、INSERT INTO employees(first_name,last_name, employee_id) VALUES ('1000, 'john','Smith');
  • E、INSERT INTO employees (employee_id) VALUES (1000);
  • F、INSERT INTO employees (employee_id, first_name, last_name) VALUES ( 1000, 'john',");

正确答案:C,E,F

第3题:

Examine the structure of the EMPLOYEES table:Column name Data type RemarksEMPLOYEE_ID NUMBER NOT NULL, Primary KeyLAST_NAME VARCNAR2(30)FIRST_NAME VARCNAR2(30)JOB_ID NUMBERSAL NUMBERMGR_ID NUMBER References EMPLOYEE_ID column DEPARTMENT_ID NUMBERYou need to create an index called NAME_IDX on the first name and last name fields of the EMPLOYEES table. Which SQL statement would you use to perform this task? ()

A. CREATE INDEX NAME _IDX (first_name, last_name);

B. CREATE INDEX NAME _IDX (first_name, AND last_name)

C. CREATE INDEX NAME_IDX ON (First_name, last_name);

D. CREATE INDEX NAME_IDX ON employees (First_name, AND last_name);

E. CREATE INDEX NAME_IDX ON employees (First_name, last_name);

F. CREATE INDEX NAME_IDX FOR employees (First_name, last_name);


参考答案:E

第4题:

Examine the structure of the EMPLOYEES table: Column name Data type Remarks EMPLOYEE_ID NUMBER NOT NULL, Primary Key LAST_NAME VARCNAR2(30) FIRST_NAME VARCNAR2(30) JOB_ID NUMBER SAL NUMBER MGR_ID NUMBER References EMPLOYEE_ID column DEPARTMENT_ID NUMBER You need to create an index called NAME_IDX on the first name and last name fields of the EMPLOYEES table. Which SQL statement would you use to perform this task? ()

  • A、CREATE INDEX NAME _IDX (first_name, last_name);
  • B、CREATE INDEX NAME _IDX (first_name, AND last_name)
  • C、CREATE INDEX NAME_IDX ON (First_name, last_name);
  • D、CREATE INDEX NAME_IDX ON employees (First_name, AND last_name);
  • E、CREATE INDEX NAME_IDX ON employees (First_name, last_name);
  • F、CREATE INDEX NAME_IDX FOR employees (First_name, last_name);

正确答案:E

第5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 UNIQUE(dept_id) FROM employees WHERE last_name='Smith';

正确答案:D

第6题:

Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE Which INSERT statement is valid?()

  • A、INSERT INTO employees (employee_id, first_name, last_name, hire_date) VALUES (1000, 'John', 'smith','01/01/01);
  • B、INSERT INTO employees(employee_id, first_name, last_name, hire_date) VALUES (1000, 'John', 'smith','01 january 01');
  • C、INSERT INTO employees(employee_id, first_name, last_name, Hire_date) VALUES (1000, 'John', 'smith', To_ date ('01/01/01));
  • D、INSERT INTO employees(employee_id, first_name, last_name, hire_date) VALUES (1000, 'John', 'smith','01-Jan-01');

正确答案:A

第7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 of the minimum salary is less then 5000 and the 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)
  • E、SELECT dept_id, MIN(salary), MAX(salary) FROM employees GROUP BY dept_id, salary HAVING MIN (salary) <5000 AND MAX (salary) > 15000;

正确答案:D

第8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;


参考答案:B

第9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.

正确答案:B

第10题:

Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) Which three statements insert a row into the table? ()

  • A、INSERT INTO employees VALUES (NULL, 'John', 'smith');
  • B、INSERT INTO employees (first_name, last_name) VALUES ('John', 'smith');
  • C、INSERT INTO employees VALUES ('1000, 'John', 'smith');
  • D、INSERT INTO employees (first_name, last_name, employee_id) VALUES (1000, 'John', 'smith');
  • E、INSERT INTO employees (employee_id) VALUES (1000);
  • F、INSERT INTO employees ( employee_id, first_name, last_name, ) VALUES (1000, 'John','');

正确答案:C,E,F

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