1Z0-007章节练习(2019.12.11)

单项选择题
What does the TRUNCATE statement do?（）
A. Removes the table
B. Removes all rows from a table
C. Shortens the table to 10 rows
D. Removes all columns from a table
E. Removes foreign keys from a table
多项选择题
Examine the structure of the EMPLOYEES table:EMPLOYEE_ID NUMBER Primary KeyFIRST_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', 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', ' ');
单项选择题
Which statement correctly describes SQL and /SQL*Plus?（）
A. Both SQL and /SQL*plus allow manipulation of values in the database.
B. /SQL* Plus recognizes SQL satement and sends them to the server; SQL is the Oracle proprietary interface for executing SQL statements.
C. /SQL* Plus language for communicating with the Oracle server to access data; SQL recognizes SQL statements and sends them to the server.
D. /SQL manipulates data and table definition in the database; /SQL* Plus does not allow manipulation of values in the database.
单项选择题
You need to change the definition of an existing table. The COMMERCIALS table needs its DESCRIPTION column changed to hold varying length characters up to 2000 bytes. The column can currently hold 1000 bytes per value. The table contains 20000 rows.Which statement is valid?（）
A. ALTER TABLE commercials MODIFY (description CHAR2(2000));
B. ALTER TABLE commercials CHANGE (description CHAR2(2000));
C. ALTER TABLE commercials CHANGE (description VARCHAR2 (2000));
D. ALTER TABLE commercials MODIFY (description VARCHAR2 (2000));
E. You cannot increase the size of a column if the table has rows.
单项选择题
What is true about sequences? （）
A. Once created, a sequence belongs to a specific schema.
B. Once created, a sequence is linked to a specific table.
C. Once created, a sequence is automatically available to all users.
D. Only the DBA can control which sequence is used by a certain table.
E. Once created, a sequence is automatically used in all INSERT and UPDATE statements.
单项选择题
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?（）
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.
多项选择题
When should you create a role?（）
A. To simplify the process of creating new users using the CREATE USER xxx IDENTIFIED by yyy statement.
B. To grant a group of relate privileges to a user.
C. When the number of people using the database is very high.
D. To simplify the process of granting and revoking privileges.
E. To simplify profile maintenance for a user who is constantly traveling.
多项选择题
Which two tasks can you perform using only the TO_CHAR function? （）
A. convert 10 to 'TEN'
B. convert '10' to 10
C. convert 10 to '10'
D. convert 'TEN' to 10
E. convert a date to a character expression
F. convert a character expression to a date
多项选择题
Which two are character manipulation functions? （）
A. TRIM
B. REPLACE
C. TRUNC
D. TO_DATE
E. MOD
F. CASE
多项选择题
Click the Exhibit button and examine the data in the EMPLOYEES table. Which three subqueries work?（）
A.SELECT * FROM employees where salary > (SELECT MIN(salary) FROM employees GROUP BY department_id);
B.SELECT * FROM employees WHERE salary = (SELECT AVG(salary) FROM employees GROUP BY department_id);
C.SELECT distinct department_id FROM employees WHERE salary > ANY (SELECT AVG(salary) FROM employees GROUP BY department_id);
D.SELECT department_id FROM employees WHERE salary > ALL (SELECT AVG(salary) FROM employees GROUP BY department_id);
E.SELECT last_name FROM employees WHERE salary > ANY (SELECT MAX(salary) FROM employees GROUP BY department_id);
F.SELECT department_id FROM employees WHERE salary > ALL (SELECT AVG(salary) FROM employees GROUP BY AVG(SALARY));