单选题Evaluate these two SQL statements: SELECT last_name, salary , hire_date FROM EMPLOYEES ORDER BY salary DESC; SELECT last_name, salary , hire_date FROM EMPLOYEESORDER BY 2 DESC; What is true about them?（）A The two statements produce identical results.B

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单选题

Evaluate these two SQL statements: SELECT last_name, salary , hire_date FROM EMPLOYEES ORDER BY salary DESC; SELECT last_name, salary , hire_date FROM EMPLOYEESORDER BY 2 DESC; What is true about them?（）

The two statements produce identical results.

The second statement returns a syntax error.

There is no need to specify DESC because the results are sorted in descending order by default.

The two statements can be made to produce identical results by adding a column alias for the salary column in the second SQL statement.

参考答案和解析

正确答案： D

解析：暂无解析

更多“单选题Evaluate these two SQL statements: SELECT last_name, salary , hire_date FROM EMPLOYEES ORDER BY salary DESC; SELECT last_name, salary , hire_date FROM EMPLOYEESORDER BY 2 DESC; What is true about them?（）A The two statements produce identical results.B ”相关问题

第1题

The EMPLOYEES table contains these columns: LAST_NAME VARCHAR2 (25) SALARY NUMBER (6,2) COMMISSION_PCT NUMBER (6) You need to write a query that will produce these results: 1.Display the salary multiplied by the commission_pct. 2.Exclude employees with a zero commission_pct. 3.Display a zero for employees with a null commission value. Evaluate the SQL statement: SELECT LAST_NAME, SALARY*COMMISSION_PCT FROM EMPLOYEES WHERE COMMISSION_PCT IS NOT NULL; What does the statement provide?（）A、all of the desired resultsB、two of the desired resultsC、one of the desired resultsD、an error statement

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第2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；

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第3题

The EMPLOYEE tables has these columns: LAST_NAME VARCHAR2(35) SALARY NUMBER(8,2) COMMISSION_PCT NUMBER(5,2) You want to display the name and annual salary multiplied by the commission_pct for all employees. For records that have a NULL commission_pct, a zero must be displayed against the calculated column. Which SQL statement displays the desired results?（）A、SELECT last_name, (salary * 12) * commission_pct FROM EMPLOYEES;B、SELECT last_name, (salary * 12) * IFNULL(commission_pct, 0) FROM EMPLOYEES;C、SELECT last_name, (salary * 12) * NVL2(commission_pct, 0) FROM EMPLOYEES;D、SELECT last_name, (salary * 12) * NVL(commission_pct, 0) FROM EMPLOYEES;

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第4题

Management has asked you to calculate the value 12*salary* commission_pct for all the employees in the EMP table. The EMP table contains these columns: LAST NAME VARCNAR2(35) NOT NULL SALARY NUMBER(9,2) NOT NULL COMMISION_PCT NUMBER(4,2) Which statement ensures that a value is displayed in the calculated columns for all employees?（）A、SELECT last_name, 12*salary* commission_pct FROM emp;B、SELECT last_name, 12*salary* (commission_pct,0) FROM emp;C、SELECT last_name, 12*salary*(nvl(commission_pct,0)) FROM emp;D、SELECT last_name, 12*salary*(decode(commission_pct,0)) FROM emp;

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第5题

Evaluate these two SQL statements: SELECT last_name, salary , hire_date FROM EMPLOYEES ORDER BY salary DESC; SELECT last_name, salary , hire_date FROM EMPLOYEES ORDER BY 2 DESC; What is true about them?（）A、The two statements produce identical results.B、The second statement returns a syntax error.C、There is no need to specify DESC because the results are sorted in descending order by default.D、The two statements can be made to produce identical results by adding a column alias for the salary column in the second SQL statement.

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第6题

The EMPLOYEES table contains these columns: LAST_NAME VARCHAR2 (25) SALARY NUMBER (6,2) COMMISSION_PCT NUMBER (6) You need to write a query that will produce these results: 1. Display the salary multiplied by the commission_pct. 2. Exclude employees with a zero commission_pct. 3. Display a zero for employees with a null commission value. Evaluate the SQL statement: SELECT LAST_NAME, SALARY*COMMISSION_PCT FROM EMPLOYEES WHERE COMMISSION_PCT IS NOT NULL; What does the statement provide? （）A、All of the desired resultsB、Two of the desired resultsC、One of the desired resultsD、An error statement

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第7题

Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) DEPARTMENT_ID NUMBER SALARY NUMBER What is the correct syntax for an inline view? （）A、SELECT a.last_name, a.salary, a.department_id, b.maxsal FROM employees a, (SELECT department_id, max(salary)maxsal FROM employees GROUP BY department_id) b WHERE a.department_id = b.department_id AND a.salary < b.maxsal;B、SELECT a.last name, a.salary, a.department_id FROM employees a WHERE a.department_id IN (SELECT department_id FROM employees b GROUP BY department_id having salary = (SELECT max(salary) from employees))C、SELECT a.last_name, a.salary, a.department_id FROM employees a WHERE a.salary = (SELECT max(salary) FROM employees b WHERE a.department _ id = b.department _ id);D、SELECT a.last_name, a.salary, a.department_id FROM employees a WHERE (a.department_id, a.salary) IN (SELECT department_id, a.salary) IN (SELECT department_id max(salary) FROM employees b GROUP BY department_id ORDER BY department _ id);

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单选题Evaluate these two SQL statements: SELECT last_name, salary , hire_date FROM EMPLOYEES ORDER BY salary DESC; SELECT last_name, salary , hire_date FROM EMPLOYEESORDER BY 2 DESC; What is true about them?（）A The two statements produce identical results.B

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更多“单选题Evaluate these two SQL statements: SELECT last_name, salary , hire_date FROM EMPLOYEES ORDER BY salary DESC; SELECT last_name, salary , hire_date FROM EMPLOYEESORDER BY 2 DESC; What is true about them?（）A The two statements produce identical results.B ”相关问题

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