单项选择题
A. ALTER TABLE commercials MODIFY (description CHAR2(2000));
B. ALTER TABLE commercials CHANGE (description CHAR2(2000));
C. ALTER TABLE commercials CHANGE (description VARCHAR2(2000));
D. ALTER TABLE commercials MODIFY (description VARCHAR2(2000));
E. You cannot increase the size of a column if the table has rows.
单项选择题 What does the TRUNCATE statement do?()
单项选择题 Which is an /SQL*Plus command?()
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?()