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单选题
创建哪一项会使以下语句的执行速度更快（） SELECT * FROM employees WHERE LOWER(last_name) = 'chang'.
A
同义词
B
一个索引，普通索引或基于函数的索引
C
组合索引
D
不创建任何项；无法提高此语句的性能
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更多 “单选题创建哪一项会使以下语句的执行速度更快（） SELECT * FROM employees WHERE LOWER(last_name) = 'chang'.A 同义词B 一个索引，普通索引或基于函数的索引C 组合索引D 不创建任何项；无法提高此语句的性能” 相关考题
考题
当你执行以下查询语句:SELECT employeesno,ename FROM employees WHERE employeesno=7782 OR employeesno=7876;在WHERE语句中,以下哪个操作符可以取代OR?()
A.INB.BETWEEN……andC.LIKED.=
考题
有个员工表employees,该表中有职务列。你想检查哪些员工的信息中没有填写职务一栏,应该使用()。
A.Select*from employees where职务＝NULLB.Select*from employees where职务=‘NULL’C.Select*from employees where职务ISNULLD.Select*from employees where职务IS‘NULL’
考题
下列哪个语句查出雇员表(employees)里的雇员名字(ename)是‘SMITH’的信息,并且给雇员名字(ename)列定义一个别名Name()。
A.select employeesno，ename Name，job from employees where ename=‘SMITH’B.select employeesno，ename ‘Name’，job from employees where ename=SMITHC.select employeesno，ename “Name”，job from employees where ename=‘SMITH’D.select employeesno，ename ‘Name’，job frome mployees wheree name=‘SMITH’
考题
SQL语句：SELECT*FROM班级WHERE班级号NOT IN;(SELECT班级号FROM学生)该语句等价于：SELECT*FROM班级WHERE NOT______;(SELECT*FROM学生WHERE班级号=班级.班级号)
考题
有SQL语句： SELECT DISTINCT系号FROM教师WHERE工资＞=； ALL(SELECT工资FROM教师WHERE系号="02") 与如上语句等价的SQL语句是A．SELECT DISTINCT系号FROM教师WHERE工资＞=； (SELECT MAX(工资)FROM教师WHERE系号="02")B．SELECT DISTINCT系号FROM教师WHERE工资＞=； (SELECT MIN(工资)FROM教师WHERE系号="02")C．SELECT DISTINCT系号FROM教师WHERE工资＞=； ANY(SELECT工资FROM教师WHERE系号="02")D．SELECT DISTINCT系号FROM教师WHERE工资＞=； SOME(SELECT工资FROM教师WHERE系号="02")
考题
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 ANG (SALARY));
考题
Examine the data in the EMPLOYEES table:LAST_NAME DEPARTMENT_ID SALARYGetz 10 3000Davis 20 1500Bill 20 2200Davis 30 5000...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 ANG (SALARY));
考题
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));
考题
对由SELECT--FROM—WHERE—GROUP--ORDER组成的SQL语句，其在被DBMS处理时，各子句的执行次序为()A.SELECT—FROM—GROUP—WHERE—ORDERB.FROM——SELECT--WHERE——GROUP——ORDERC.FROM——WHERE——GROUP——SELECT——ORDERD.SELECT——FROM——WHERE——GROUP——ORDER
考题
下列哪个语句查出雇员表（employees）里的雇员名字（ename）是‘SMITH’的信息，并且给雇员名字（ename）列定义一个别名Name（）。A、select employeesno，ename Name，job from employees where ename=‘SMITH’B、select employeesno，ename ‘Name’，job from employees where ename=SMITHC、select employeesno，ename “Name”，job from employees where ename=‘SMITH’D、select employeesno，ename ‘Name’，job frome mployees wheree name=‘SMITH’
考题
数据库benet中有个员工表employees，该表中有职务列，可以实现检查哪些员工的信息中没有填写职务一栏，应该使用子句（）A、Select*from employees where职务＝NULLB、Select*from employees where职务=’NULL’C、Select*from employees where职务ISNULLD、Select*from employees where职务IS‘NULL’
考题
当你执行以下查询语句：SELECT employeesno，ename FROM employees WHERE employeesno=7782 OR employeesno=7876；在WHERE语句中，以下哪个操作符可以取代OR？（）A、INB、BETWEEN……andC、LIKED、=
考题
有个员工表employees，该表中有职务列。你想检查哪些员工的信息中没有填写职务一栏，应该使用（）。A、Select*from employees where职务＝NULLB、Select*from employees where职务=‘NULL’C、Select*from employees where职务ISNULLD、Select*from employees where职务IS‘NULL’
考题
对由SELECT--FROM—WHERE—GROUP--ORDER组成的SQL语句，其在被DBMS处理时，各子句的执行次序为（）A、SELECT—FROM—GROUP—WHERE—ORDERB、FROM--WHERE——GROUP——ORDER——SELECTC、FROM——WHERE——GROUP——SELECT——ORDERD、SELECT——FROM——WHERE——GROUP——ORDER
考题
下面哪条语句可以取出薪水最高的前三个人：（）A、SELECT * FROM （SELECT * FROM EMPLOYEES ORDER BY SALARY ）；B、SELECT * FROM （SELECT * FROM EMPLOYEES ORDER BY SALARY ） WHERE ROWNUM=3；C、SELECT * FROM （SELECT * FROM EMPLOYEES ORDER BY SALARY DESC） WHERE ROWNUM=3；D、SELECT * FROM EMPLOYEES WHERE ROWNUM=3 ORDER BY SALARY DESC；
考题
查询student表中的所有非空email信息，以下语句正确的是（）。A、Select email from student where email !=nullB、Select email from student where email not is nullC、Select email from student where email nullD、Select email from student where email is not null
考题
创建哪一项会使以下语句的执行速度更快（） SELECT * FROM employees WHERE LOWER(last_name) = 'chang'.A、同义词B、一个索引，普通索引或基于函数的索引C、组合索引D、不创建任何项；无法提高此语句的性能
考题
查询student表中的所有非空email信息，以下语句正确的是（）A、Select email from student where email!=nullB、Select email from student where emailnotisnullC、Select email from student where emailnullD、Select email from student where emailisnotnull
考题
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';
考题
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');
考题
Examine the data in the EMPLOYEES table: LAST_NAME DEPARTMENT_ID SALARY Getz 10 3000 Davis 20 1500 Bill 20 2200 Davis 30 5000 ... 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 ANG (SALARY));
考题
多选题Examine the data in the EMPLOYEES table: Which three subqueries work? （）ASELECT * FROM employees where salary (SELECT MIN(salary) FROM employees GROUP BY department _ id);BSELECT * FROM employees WHERE salary = (SELECT AVG(salary) FROM employees GROUP BY department _ id);CSELECT distinct department_id FROM employees Where salary ANY (SELECT AVG(salary) FROM employees GROUP BY department _ id);DSELECT department_id FROM employees WHERE SALARY ALL (SELECT AVG(salary) FROM employees GROUP BY department _ id);ESELECT last_name FROM employees Where salary ANY (SELECT MAX(salary) FROM employees GROUP BY department _ id);FSELECT department_id FROM employees WHERE salary ALL (SELECT AVG(salary) FROM employees GROUP BY ANG (SALARY));
考题
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? （）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')'
考题
单选题当你执行以下查询语句：SELECT employeesno，ename FROM employees WHERE employeesno=7782 OR employeesno=7876；在WHERE语句中，以下哪个操作符可以取代OR？（）A
INB
BETWEEN……andC
LIKED
=
考题
多选题Click the Exhibit button and examine the data in the EMPLOYEES table. Which three subqueries work?（）ASELECT * FROM employees where salary (SELECT MIN(salary) FROM employees GROUP BY department_id);BSELECT * FROM employees WHERE salary = (SELECT AVG(salary) FROM employees GROUP BY department_id);CSELECT distinct department_id FROM employees WHERE salary ANY (SELECT AVG(salary) FROM employees GROUP BY department_id);DSELECT department_id FROM employees WHERE salary ALL (SELECT AVG(salary) FROM employees GROUP BY department_id);ESELECT last_name FROM employees WHERE salary ANY (SELECT MAX(salary) FROM employees GROUP BY department_id);FSELECT department_id FROM employees WHERE salary ALL (SELECT AVG(salary) FROM employees GROUP BY AVG(SALARY));
考题
单选题下面哪条语句可以取出薪水最高的前三个人：（）A
SELECT * FROM （SELECT * FROM EMPLOYEES ORDER BY SALARY ）；B
SELECT * FROM （SELECT * FROM EMPLOYEES ORDER BY SALARY ） WHERE ROWNUM=3；C
SELECT * FROM （SELECT * FROM EMPLOYEES ORDER BY SALARY DESC） WHERE ROWNUM=3；D
SELECT * FROM EMPLOYEES WHERE ROWNUM=3 ORDER BY SALARY DESC；
考题
多选题Examine the data in the EMPLOYEES table: LAST_NAME DEPARTMENT_ID SALARY Getz 10 3000 Davis 20 1500 Bill 20 2200 Davis 30 5000 ... Which three subqueries work? （）ASELECT * FROM employees where salary (SELECT MIN(salary) FROM employees GROUP BY department _ id);BSELECT * FROM employees WHERE salary = (SELECT AVG(salary) FROM employees GROUP BY department _ id);CSELECT distinct department_id FROM employees Where salary ANY (SELECT AVG(salary) FROM employees GROUP BY department _ id);DSELECT department_id FROM employees WHERE SALARY ALL (SELECT AVG(salary) FROM employees GROUP BY department _ id);ESELECT last_name FROM employees Where salary ANY (SELECT MAX(salary) FROM employees GROUP BY department _ id);FSELECT department_id FROM employees WHERE salary ALL (SELECT AVG(salary) FROM employees GROUP BY ANG (SALARY));
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