Chapter 5, Problem 3MC

Which of the following commands removes all data from a table but leaves the tables structure intact? a. ALTER TABLE secustomerorders DROP UNUSED COLUMNS; b. TRUNCATE TABLE secustomerorders; c. DELETE TABLE secustomerorders; d. DROP TABLE secustomerorders;

Which of the following is true? All data in a table can be recovered if the table is dropped with the PURGE option. All data in a table can be recovered from the recycle bin if the table is dropped. All data in a table is lost if the table is dropped. All of the above statements are true.

Which of the following statements is correct? A table can contain a maximum of only one column marked as unused. You can delete a table by removing all columns in the table. Using the SET UNUSED clause allows you to free up storage space used by a column. None of the above statements are correct.

Which of the following statements deletes all rows in the HOMEWORK10 table? a. DELETE FROM homework10; b. DELETE . FROM homework10; c. DELETE FROM homework10; d. DELETE FROM homework10 WHERE amid = ; e. Both c and d delete all rows in the HOMEWORK10 table.

Which of the following is true? a. If you truncate a table, you cant add new data to the table. b. If you change the default value of an existing column, all existing rows containing a NULL value in the same column are set to the new DEFAULT value. c. If you delete a column from a table, you cant add a column to the table with the same name as the previously deleted column. d. If you add a column to an existing table, its always added as the last column of the table.

Which of the following commands creates a new table containing a virtual column? a. CREATE TABLE newt able AS (SELECT order#, title, quantity, retail FROM orders); b. CREATE TABLE newt able (price NUMBER (3), total NUMBER (8, 2)); c. CREATE TABLE newt able (calc1 NUMBER (4), calc2 NUMBER (4); d. CREATE TABLE newt able (cola NUMBER (3), colb NUMBER (3), cole AS (cola+colb));

Which command should you use to copy data from one table and have it added to an existing table?

Which of the following commands creates a new table containing two columns? CREATE TABLE newname (coll DATE, col2 VARCHAR2); CREATE TABLE newname AS (SELECT title, retail, cost FROM books); CREATE TABLE newname (col1, co12); CREATE TABLE newname (col1 DATE DEFAULT SYSDATE, co12 VARCHAR2 (1));

Which of the following commands drops any columns marked as unused from the SECUSTOMERORDERS table? DROP COLUMN FROM secustomerorders WHERE column_status = UNUSED ALTER TABLE secustomerorders DROP UNUSED COLUMNS; ALTER TABLE secustomerorders DROP (unused); DROP UNUSED COLUMNS;