多项选择题
Evaluate the SQL statement: TRUNCATE TABLE DEPT;Which three are true about the SQL statement? （）
A.It releases the storage space used by the table.
B.It does not release the storage space used by the table.
C.You can roll back the deletion of rows after the statement executes.
D.You can NOT roll back the deletion of rows after the statement executes.
E.An attempt to use DESCRIBE on the DEPT table after the TRUNCATE statement executes will display an error.
F.You must be the owner of the table or have DELETE ANY TABLE system privileges to truncate the DEPT table.
相关考题
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单项选择题
The EMPLOYEES table contains these columns: LAST_NAME VARCHAR2 (25) SALARY NUMBER (6,2) COMMISSION_PCT NUMBER (6) You need to write a query that will produce these results: 1.Display the salary multiplied by the commission_pct. 2.Exclude employees with a zero commission_pct. 3.Display a zero for employees with a null commission value. Evaluate the SQL statement: SELECT LAST_NAME, SALARY*COMMISSION_PCT FROM EMPLOYEES WHERE COMMISSION_PCT IS NOT NULL; What does the statement provide?（）
A.all of the desired results
B.two of the desired results
C.one of the desired results
D.an error statement -
多项选择题
Which three are DATETIME data types that can be used when specifying column definitions? （）
A.TIMESTAMP
B.INTERVAL MONTH TO DAY
C.INTERVAL DAY TO SECOND
D.INTERVAL YEAR TO MONTH
E.TIMESTAMP WITH DATABASE TIMEZONE -
单项选择题
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 ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
E.ALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
