多项选择题

A. You can use aggregate functions in any clause of a S……

Which two are true about aggregate functions? （）

A. You can use aggregate functions in any clause of a SELECT statement.
B. You can use aggregate functions only in the column list of the SELECT clause and in the WHERE clause of a SELECT statement.
C. You can mix single row columns with aggregate functions in the column list of a SELECT statement by grouping on the single row columns.
D. You can pass column names, expressions, constants, or functions as parameters to an aggregate function.
E. You can use aggregate functions on a table, only by grouping the whole table as one single group.
F. You cannot group the rows of a table by more than one column while using aggregate functions.

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单项选择题The STUDENT_GRADES table has these columns: STUDENT_ID NUMBER(12) SEMESTER_END DATE GPA NUMBER(4,3) The registrar has asked for a report on the average grade point average (GPA) for students enrolled during semesters that end in the year 2000. Which statement accomplish this? （）

A. SELECT AVERAGE(gpa) FROM student_grades WHERE semester _ end > '01-JAN-2000' and semester end <31-DEC-2000';
B. SELECT COUNT(gpa) FROM student grades WHERE semester _ end > '01-JAN-2000' and semester end <31-DEC-2000';
C. SELECT MIN(gpa) FROM student grades WHERE semester _ end > '01-JAN-2000' and semester end <31-DEC-2000';
D. SELECT AVG(gpa) FROM student_grades WHERE semester _ end BETWEEN '01-JAN-2000' and '31-DEC-2000';
E. SELECT SUM(gpa) FROM student grades WHERE semester _ end > '01-JAN-2000' and semester end <31-DEC-2000';
F. SELECT MEDIAN(gpa) FROM student_grades WHERE semester _ end > '01-JAN-2000' and semester end <31-DEC-2000';

单项选择题Examine the structure if the EMPLOYEES table: Column name Data Type Remarks EMPLOYEE_ID NUMBER NOT NULL, Primary Key EMP_NAME VARCHAR2(30) JOB_ID VARCHAR2(20) NOT NULL SAL NUMBER MGR_ID NUMBER References EMPLOYEE_ID column DEPARTMENT_ID NUMBER Foreign key to DEPARTMENT_ID column of the DEPARTMENTS 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;

多项选择题Which three SELECT statements displays 2000 in the format $2,000.00 ? （）

A. SELECT TO CNAR(2000, '$#,###.##') FROM dual;
B. SELECT TO CNAR(2000, '$0,000.00') FROM dual;
C. SELECT TO CNAR(2000, '$9,999.00') FROM dual;
D. SELECT TO CNAR(2000, '$9,999.99') FROM dual;
E. SELECT TO CNAR(2000, '$2,000.00') FROM dual;
F. SELECT TO CNAR(2000, '$N,NNN.NN') FROM dual;

多项选择题For which two constraints does the Oracle Server implicitly create a unique index? （）

A. NOT NULL
B. PRIMARY KEY
C. FOREIGN KEY
D. CHECK
E. UNIQUE

单项选择题You created a view called EMP_DEPT_VU that contains three columns from the EMPLOYEES and DEPARTMENTS tables: EMPLOYEE_ID, EMPLOYEE_NAME AND DEPARTMENT_NAME. The DEPARTMENT_ID column of the EMPLOYEES table is the foreign key to the primary key DEPARTMENT_ID column of the DEPARTMENTS table. You want to modify the view by adding a fourth column, MANAGER_ID of NUMBER data type from the EMPLOYEES tables. How can you accomplish this task? （）

A. ALTER VIEW EMP_dept_vu (ADD manger_id NUMBER);
B. MODIFY VIEW EMP_dept_vu (ADD manger_id NUMBER);
C. ALTER VIEW emp_dept_vu AS SELECT employee_id, employee_name, department_name, manager_id FROM employee e, departments d WHERE e.department _ id = d.department_id;
D. MODIFY VIEW emp_dept_vu AS SELECT employee_id, employee_name, department_name, manager_id FROM employees e, departments d WHERE e.department _ id = d.department_id;
E. CREATE OR REPLACE VIEW emp_dept_vu AS SELECT employee_id, employee_name, department_name, manager_id FROM employees e, departments d WHERE e.department _ id = d.department_id;
F. You must remove the existing view first, and then run the CREATE VIEW command with a new column list to modify a view.