What are two reasons to create synonyms? （）……

单项选择题Which SQL statement returns a numeric value?（）

A. SELECT ADD_MONTHS(MAX(hire_Date), 6) FROM EMP;
B. SELECT ROUND(hire_date) FROM EMP;
C. SELECT sysdate-hire_date FROM EMP;
D. SELECT TO_NUMBER(hire_date + 7) FROM EMP;

单项选择题Examine this statement: SELECT student_id, gpa FROM student_grades WHERE gpa >&&value; You run the statement once, and when prompted you enter a value of 2.0. A report is produced. What happens when you run the statement a second time?（）

A. An error is returned.
B. You are prompted to enter a new value.
C. A report is produced that matches the first report produced.
D. You are asked whether you want a new value or if you want to run the report based on the previous value.

多项选择题In which four clauses can a subquery be used? （）

A. in the INTO clause of an INSERT statement
B. in the FROM clause of a SELECT statement
C. in the GROUP BY clause of a SELECT statement
D. in the WHERE clause of a SELECT statement
E. in the SET clause of an UPDATE statement
F. in the VALUES clause of an INSERT statement

单项选择题The STUDENT_GRADES table has these columns: STUDENT_ID NUMBER(12) SEMESTER_END DATE GPA NUMBER(4,3) Which statement finds the highest grade point average (GPA) per semester?（）

A. SELECT MAX (gpa) FROM student _ grades WHERE gpa IS NOT NULL;
B. SELECT (gpa) FROM student _ grades GROUP BY semester_end WHERE gpa IS NOT NULL;
C. SELECT MAX (gpa) FROM student _ grades WHERE gpa IS NOT NULL GROUP BY semester_end;
D. SELECT MAX (gpa) GROUP BY semester_end WHERE gpa IS NOT NULL FROM student _ grades;
E. SELECT MAX (gpa) FROM student _ grades GROUP BY semester_end WHERE gpa IS NOT NULL;

单项选择题What is true of using group functions on columns that contain NULL values?（）

A. Group functions on columns ignore NULL values.
B. Group functions on columns returning dates include NULL values.
C. Group functions on columns returning numbers include NULL values.
D. Group functions on columns cannot be accurately used on columns that contain NULL values.
E. Group functions on columns include NULL values in calculations if you use the keyword INC_NULLS.