多项选择题
Examine the data from the EMP table:
EMP_ID DEPT_ID COMMISSION
1 10 500
2 20 1000
3 10
4 10 600
5 30 800
6 30 200
7 10
8 20 300
The COMMISSION column shows the monthly commission earned by the employee. Which three tasks would require subqueries or joins in order to perform in a single step? （）
A. Deleting the records of employees who do not earn commission.
B. Increasing the commission of employee 3 by the average commission earned in department 20.
C. Finding the number of employees who do NOT earn commission and are working for department 20.
D. Inserting into the table a new employee 10 who works for department 20 and earns a commission that is equal to the commission earned by employee 3.
E. Creating a table called COMMISSION that has the same structure and data as the columns EMP_ID and COMMISSIONS of the EMP table.
F. Decreasing the commission by 150 for the employees who are working in department 30 and earning a commission of more then 800.
相关考题
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多项选择题
Which four statements correctly describe functions that are available in SQL? （）
A. INSTR returns the numeric position of a named character.
B. NVL2 returns the first non-null expression in the expression list.
C. TRUNCATE rounds the column, expression, or value to n decimal places.
D. DECODE translates an expression after comparing it to each search value.
E. TRIM trims the heading of trailing characters (or both) from a character string.
F. NVL compares two expressions and returns null if they are equal, or the first expression of they are not equal.
G. NULLIF compares twp expressions and returns null if they are equal, or the first expression if they are not equal. -
单项选择题
Examine the structure if the EMPLOYEES table: You need to create a view called EMP_VU that allows the user to insert rows through the view. Which SQL statement, when used to create the EMP_VU view, allows the user to insert rows?（）
A. CREATE VIEW emp_Vu AS SELECT employee_id, emp_name, department_id FROM employees WHERE mgr_id IN (102, 120);
B. CREATE VIEW emp_Vu AS SELECT employee_id, emp_name, job_id department_id FROM employees WHERE mgr_id IN (102, 120);
C. CREATE VIEW emp_Vu AS SELECT department_id, SUM(sal) TOTALSAL FROM employees WHERE mgr_id IN (102, 120) GROUP BY department_id;
D. CREATE VIEW emp_Vu AS SELECT employee_id, emp_name, job_id, DISTINCT department_id FROM employees; -
单项选择题
Examine the structure of the STUDENTS table: STUDENT_ID NUMBER NOT NULL, Primary Key STUDENT_NAME VARCHAR2(30) COURSE_ID VARCHAR2(10) NOT NULL MARKS NUMBER START_DATE DATE FINISH_DATE DATE You need to create a report of the 10 students who achieved the highest ranking in the course INT SQL and who completed the course in the year 1999. Which SQL statement accomplishes this task?（）
A. SELECT student_ id, marks, ROWNUM "Rank" FROM students WHERE ROWNUM <= 10 AND finish_date BETWEEN '01-JAN-99' AND '31-DEC-99' AND course_id = 'INT_SQL' ORDER BY marks DESC;
B. SELECT student_id, marks, ROWID "Rank" FROM students WHERE ROWID <= 10 AND finish_date BETWEEN '01-JAN-99' AND '31-DEC-99' AND course_id = 'INT_SQL' ORDER BY marks;
C. SELECT student_id, marks, ROWNUM "Rank" FROM (SELECT student_id, marks FROM students WHERE ROWNUM <= 10 AND finish_date BETWEEN '01-JAN-99' AND '31-DEC-99' AND course_id = 'INT_SQL' ORDER BY marks DESC);
D. SELECT student_id, marks, ROWNUM "Rank" FROM (SELECT student_id, marks FROM students ORDER BY marks DESC) WHERE ROWNUM <= 10 AND finish_date BETWEEN '01-JAN-99' AND '31-DEC-99' AND course _ id ='INT _ SQL';
