单选题Examine the structure of the EMPLOYEES and NEW_EMPLOYEES tables: EMPLOYEES EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2 (25) LAST_NAME VARCHAR2 (25) HIRE_DATE DATE NEW EMPLOYEES EMPLOYEE_ID NUMBER Primary Key NAME VARCHAR2 (60) Which DELETE state

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单选题

Examine the structure of the EMPLOYEES and NEW_EMPLOYEES tables: EMPLOYEES EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2 (25) LAST_NAME VARCHAR2 (25) HIRE_DATE DATE NEW EMPLOYEES EMPLOYEE_ID NUMBER Primary Key NAME VARCHAR2 (60) Which DELETE statement is valid?（）

DELETE FROM employees WHERE employee_id = (SELECT employee_id FROM employees);

DELETE * FROM employees WHERE employee_id = (SELECT employee_id FROM new_ employees);

DELETE FROM employees WHERE employee_id IN (SELECT employee_id FROM new_employees WHERE name = ('Carrey')'

DELETE * FROM employees WHERE employee_id IN (SELECT employee_id FROM new_employees WHERE last_ name = ('Carrey')'

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第1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2题：

You own a table called EMPLOYEES with this table structure: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE What happens when you execute this DELETE statement? DELETE employees;（）

A、You get an error because of a primary key violation.
B、The data and structure of the EMPLOYEES table are deleted.
C、The data in the EMPLOYEES table is deleted but not the structure.
D、You get an error because the statement is not syntactically correct.

正确答案:C

第3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4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 UPDATE statement is valid?（）

A、UPDATE employees SET first_name = 'John' SET last_name ='Smith' WHERE employee_id = 180;
B、UPDATE employees SET first_name = 'John', SET last_name ='Smith' WHERE employee_id = 180;
C、UPDATE employees SET first_name = 'John' AND last_name ='Smith' WHERE employee_id = 180;
D、UPDATE employees SET first_name = 'John', last_name ='Smith' WHERE employee_id = 180;

正确答案:D

第5题：

Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE You issue these statements: CREATE table new_emp ( employee_id NUMBER, name VARCHAR2(30)); INSERT INTO new_emp SELECT employee_id , last_name from employees; Savepoint s1; UPDATE new_emp set name = UPPER(name); Savepoint s2; Delete from new_emp; Rollback to s2; Delete from new_emp where employee_id =180; UPDATE new_emp set name = 'James'; Rollback to s2; UPDATE new_emp set name = 'James' WHERE employee_id =180; Rollback; At the end of this transaction, what is true?（）

A、You have no rows in the table.
B、You have an employee with the name of James.
C、You cannot roll back to the same savepoint more than once.
D、Your last update fails to update any rows because employee ID 180 was already deleted.

正确答案:A

第6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7题：

Examine the structure of the EMPLOYEES and DEPARTMENTS tables: EMPLOYEESColumn name Data type Remarks EMPLOYEE_ID NUMBER NOT NULL, Primary Key EMP_NAME VARCHAR2 (30) JOB_ID VARCHAR2 (20) SALARY NUMBER MGR_ID NUMBER References EMPLOYEE_ID COLUMN DEPARTMENT ID NUMBER Foreign key to DEPARTMENT ID column of the DEPARTMENTS table DEPARTMENTSColumn name Data type Remarks DEPARTMENT_ID NUMBER NOT NULL, Primary Key DEPARTMENT_NAME VARCHAR2(30) MGR_ID NUMBER References MGR_ID column of the EMPLOYEES table Evaluate this SQL statement: SELECT employee_id, e.department_id, department_name, salary FROM employees e, departments d WHERE 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);

正确答案:C

第8题：

A、DELETE FROM employees WHERE employee_id = (SELECT employee_id FROM employees);
B、DELETE * FROM employees WHERE employee_id = (SELECT employee_id FROM new_ employees);
C、DELETE FROM employees WHERE employee_id IN (SELECT employee_id FROM new_employees WHERE name = ('Carrey')'
D、DELETE * FROM employees WHERE employee_id IN (SELECT employee_id FROM new_employees WHERE last_ name = ('Carrey')'

正确答案:C

第9题：

Examine the structure of the EMPLOYEES and NEW_EMPLOYEES tables: EMPLOYEES EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE NEW_EMPLOYEES EMPLOYEE_ID NUMBER Primary Key NAME VARCHAR2 (60) Which DELETE statement is valid?（）

A、DELETE FROM employees WHERE employee_id = (SELECT employee_id FROM employees);
B、DELETE * FROM employees WHERE employee_id = (SELECT employee_id FROM new_ employees);
C、DELETE FROM employees WHERE employee_id IN (SELECT employee_id FROM new_employees WHERE name = 'carrey');
D、DELETE * FROM employees WHERE employee_id IN (SELECT employee_id FROM new_employees WHERE name = 'carrey');

正确答案:C

第10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 UPDATE statement is valid? （）

A、UPDATE employees SET first_name = 'John' SET last_name = 'Smith' WHERE employee_id = 180;
B、UPDATE employees SET first_name = 'John', SET last_name = 'Smoth' WHERE employee_id = 180;
C、UPDATE employee SET first_name = 'John' AND last_name = 'Smith' WHERE employee_id = 180;
D、UPDATE employee SET first_name = 'John', last_name = 'Smith' WHERE employee_id = 180;

正确答案:D

单选题Examine the structure of the EMPLOYEES and NEW_EMPLOYEES tables: EMPLOYEES EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2 (25) LAST_NAME VARCHAR2 (25) HIRE_DATE DATE NEW EMPLOYEES EMPLOYEE_ID NUMBER Primary Key NAME VARCHAR2 (60) Which DELETE state

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