Quiz 4
Question # 1
What is the default order in which rows are sorted by when using the ORDER BY clause?
A)
Ascending
B)
Descending
C)
Random
Question # 2
Consider the following CREATE TABLE statement:
CREATE TABLE MyTable (
ID INT AUTO_INCREMENT,
PRIMARY KEY (ID));
Once the table is created, the following statements are executed:
INSERT INTO MyTable VALUES (21);
INSERT INTO MyTable VALUES ();
What will be the outcome of the following SELECT query:
SELECT * FROM MyTable ORDER BY ID;
A)
1 and 21
B)
21 and 22
C)
The second INSERT statement will give an error.
D)
The first INSERT statement will give an error.
Question # 3
Consider the same setup from the previous question. A junior member from your team writes the following INSERT query:
INSERT INTO MyTable VALUES (NULL);
What will be the outcome of the SELECT query now?
SELECT * FROM MyTable ORDER BY ID;
A)
21, 22, 23
B)
23, 22, 21
C)
The INSERT statement will give an error
D)
1, 21, 22
Question # 4
Consider the following setup:
-- Create table with a single column
CREATE TABLE MyTable (Name VARCHAR(20));
-- Insert a NULL value
INSERT INTO MyTable VALUES (NULL);
What will be the outcome of the following SELECT query:
SELECT *
FROM MyTable
WHERE Name = NULL;
A)
1 row with Name as NULL
B)
Empty Set
C)
Can’t insert a NULL value for the Name column
Question # 5
Does UNION operator include duplicates?
A)
True
B)
False
