1. What is data manipulation language (with regard to SQL)?
Data manipulation language is used to retrieve and change data in a database, specifically relational.

2. What is data definition language (with regard to SQL)?
The data definition language is in syntax similar to computer programming language and it defines data structures.

3. Describe the wild card characters that you may use in an SQL query.
Wildcards can be used in expressions. The underscore “_” can select a single character. The percent “%” can select a series of characters. The brackets “[ ]” can be used to select a range.

4. How do you alias a column in SQL? Explain and provide an example.
You can do this by using the AS keyword.

5. How would you write the WHERE clause to return all employee last names beginning with D?
- SELECT *
FROM EmployeeAddressTable
WHERE LastName LIKE d%’

6. How would you write the WHERE clause to return all employees living in Tucson, whose names begin with an S?
-SELECT *
FROM EmployeeTableTucson
Where City = Tucson
And LastName LIKE s%’

7. What is an aggregate function?
An aggregate function is an operation on several rows at a time.

8. What is the function of the term DISTINCT in a SELECT clause?
It can be used to return unique values within a monotonous table.

9. How does the ORDER BY clause work, when no other keywords related to it are specified? What about “ORDER BY EmployeeLastName DESC”?
The ORDERBY clause needs to be specified.

10. How would you write the WHERE clause to return all of the NULL values in a particular column? Explain and provide an example.
SELECT TutorKey, CourseKey, SessionDate, StudentKey
FROM Session
Where StudentKey IS NULL

11. What is a scalar function?
A scalar function only operates on one row at a time.

12. Can you use an aggregate function within a WHERE clause?
No, WHERE does not