Databases Reference
In-Depth Information
Review Questions
1.
Rewrite the following expression using the CONCAT function.
last_name || ', ' || first_name
2.
What are two ways that you can indicate a comment in a SQL command?
3.
The SQL engine converts the IN operator to a series of ________.
4.
Rewrite the following WHERE clause to be case insensitive.
where job_title like '%Manager%';
5.
What is the only group function that counts NULL values in its calculation
without using NVL or other special processing?
6.
The query results from using aggregate functions with a GROUP BY clause can
be filtered or restricted by using what clause?
7.
Identify the two special characters used with the LIKE operator and describe
what they do.
8.
Name two aggregate functions that work only on numeric columns or
expressions and two other aggregate functions that work on numeric, char-
acter, and date columns.
9.
Put the clauses of a SQL SELECT statement in the order in which they are
processed.
10.
Which operator can do valid comparisons to columns with NULL values?
11.
The SQL engine converts the BETWEEN operator to ___________.
12.
Where do NULL values end up in a sort operation?
