CMS专题
多选题Examine the description of the STUDENTS table: STD_ID NUMBER(4) COURSE_ID VARCHAR2(10) START_DATE DATE END_DATE DATE Which two aggregate functions are valid on the START_DATE column? （ ）ASUM（start_date）BAVG（start_date）CCOUNT（start_date）DAVG（start_date，
题目
SUM（start_date）
AVG（start_date）
COUNT（start_date）
AVG（start_date，end_date）
MIN（start_date）
MAXIMUM（start_date）
参考答案和解析
相似问题和答案
第1题：
A. SUM(start_date)
B. AVG(start_date)
C. COUNT(start_date)
D. AVG(start_date, end_date)
E. MIN(start_date)
F. MAXIMUM(start_date)
第2题：
You need to change the definition of an existing table. The COMMERCIALS table needs its DESCRIPTION column changed to hold varying length characters up to 1000 bytes. The column can currently hold 500 bytes per value. The table contains 20000 rows. Which statement is valid?（）
- A、ALTER TABLE commercials MODIFY (description CHAR2(1000));
- B、ALTER TABLE commercials CHANGE (description CHAR2(1000));
- C、ALTER TABLE commercials CHANGE (description VARCHAR2(1000));
- D、ALTER TABLE commercials MODIFY (description VARCHAR2(1000));
- E、You cannot increase the size of a column if the table has rows.
正确答案:D
第3题：
Examine the structure of the STUDENTS table: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.
B.
C.
D.
第4题：
A CHECK constraint is created on the OID column.
A NOT NULL constraint is created on the OID column.
The ORDERS table is the only object created in the USERS tablespace.
The ORDERS table and a unique index are created in the USERS tablespace.
The ORDERS table is created in the USERS tablespace and a unique index is created on the OID columnin the SYSTEM tablespace.
第5题：
You need to modify the STUDENTS table to add a primary key on the STUDENT_ID column. The table is currently empty.Which statement accomplishes this task?（）
- A、ALTER TABLE students ADD PRIMARY KEY student_id;
- B、ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student _ id);
- C、ALTER TABLE students ADD CONSTRAINT stud _ id _pk PRIMARY KEY (student _ id);
- D、ALTER TABLE students MODIFY CONSTRAINT stud _ id _pk PRIMARY KEY (student _ id);
正确答案:C
第6题：
Examine the command that is used to create a table： SQL> CREATE TABLE orders（oid NUMBER（6） PRIMARY KEY， odate DATE， ccode NUMBER （6）， oamtNUMBER（10，2）） TABLESPACE users； Which two statements are true about the effect of the above command（）
- A、A CHECK constraint is created on the OID column.
- B、A NOT NULL constraint is created on the OID column.
- C、The ORDERS table is the only object created in the USERS tablespace.
- D、The ORDERS table and a unique index are created in the USERS tablespace.
- E、The ORDERS table is created in the USERS tablespace and a unique index is created on the OID columnin the SYSTEM tablespace.
正确答案:B,D
第7题：
Examine the command that is used to create a table： SQL> CREATE TABLE orders（oid NUMBER（6） PRIMARY KEY， odate DATE， ccode NUMBER（6）， oamt NUMBER（10，2）） TABLESPACE users； Which two statements are true about the effect of the above command） （）
- A、A CHECK constraint is created on the OID column.
- B、A NOT NULL constraint is created on the OID column.
- C、The ORDERS table is the only object created in the USERS tablespace.
- D、The ORDERS table and a unique index are created in the USERS tablespace.
- E、The ORDERS table is created in the USERS tablespace and a unique index is created on the OIDcolumn in the SYSTEM tablespace.
正确答案:B,D
第8题：
Examine the description of the MARKS table:SUBJ1 and SUBJ2 indicate the marks obtained by a student in two subjects.Examine this SELECT statement based on the MARKS table:What is the result of the SELECT statement?（）
A. The statement executes successfully and returns the student ID and sum of all marks for each student who obtained more than the average mark in each subject.
B. The statement returns an error at the SELECT clause.
C. The statement returns an error at the WHERE clause.
D. The statement returns an error at the ORDER BY clause.
第9题：
The statement executes successfully and returns the student ID and sum of all marks for each student who obtained more than the average mark in each subject.
The statement returns an error at the SELECT clause.
The statement returns an error at the WHERE clause.
The statement returns an error at the ORDER BY clause.
第10题：
A CHECK constraint is created on the OID column.
A NOT NULL constraint is created on the OID column.
The ORDERS table is the only object created in the USERS tablespace.
The ORDERS table and a unique index are created in the USERS tablespace.
The ORDERS table is created in the USERS tablespace and a unique index is created on the OIDcolumn in the SYSTEM tablespace.