1. Which of the following is a correct statement? a. You can restore the data deleted with the DROP COLUMN clause, but not the data deleted with the SET UNUSED clause. b. You can’t create empty tables…
1. Which of the following is a correct statement?
a. You can restore the data deleted with the DROP COLUMN clause, but not the data
deleted with the SET UNUSED clause.
b. You can’t create empty tables—all tables must contain at least three rows of data.
c. A table can contain a maximum of 1000 columns.
d. The maximum length of a table name is 265 characters.
2. Which of the following is a valid SQL statement?
a. ALTER TABLE secustomersspent ADD DATE lastorder;
b. ALTER TABLE secustomerorders DROP retail;
c. CREATE TABLE newtable AS (SELECT * FROM customers);
d. ALTER TABLE drop column *;
3. Which of the following is not a correct statement?
a. A table can be modified only if it doesn’t contain any rows of data.
b. The maximum number of characters in a table name is 30.
c. You can add more than one column at a time to a table.
d. You can’t recover data contained in a table that has been truncated.
4. Which of the following is not a valid SQL statement?
a. CREATE TABLE anothernewtable (newtableid VARCHAR2(2));
b. CREATE TABLE anothernewtable (date, anotherdate)
AS (SELECT orderdate, shipdate FROM orders);
c. CREATE TABLE anothernewtable (firstdate, seconddate)
AS (SELECT orderdate, shipdate FROM orders);
d. All of the above are valid statements.
5. Which of the following is true?
a. If you truncate a table, you can’t 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 ne
OR