单项选择题
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.
相关考题
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单项选择题
The EMP table has these columns: ENAME VARCHAR2(35) SALARY NUMBER(8,2) HIRE_DATE DATE Management wants a list of names of employees who have been with the company for more than five years. Which SQL statement displays the required results? （）
A. SELECT ENAME FROM EMP WHERE SYSDATE-HIRE_DATE >5;
B. SELECT ENAME FROM EMP WHERE HIRE_DATE-SYSDATE >5;
C. SELECT ENAME FROM EMP WHERE (SYSDATE_HIRE_DATE)/365 >5;
D. SELECT ENAME FROM EMP WHERE (SYSDATE_HIRE_DATE)*/365 >5; -
单项选择题
What is necessary for your query on an existing view to execute successfully? （）
A. The underlying tables must have data.
B. You need SELECT privileges on the view.
C. The underlying tables must be in the same schema.
D. You need SELECT privileges only on the underlying tables. -
多项选择题
Which two statements accurately describe a role? （）
A. A role can be given to a maximum of 1000 users.
B. A user can have access to a maximum of 10 roles.
C. A role can have a maximum of 100 privileges contained in it.
D. Privileges are given to a role by using the CREATE ROLE statement.
E. A role is a named group of related privileges that can be granted to the user.
F. A user can have access to several roles, and several users can be assigned the same role.
