Database Modeling: Querying

Question 1

What does DML stand for and what keywords are associated with it?

Answer 1

Data Manipulation Language: SELECT, INSERT, UPDATE, DELETE. Used to work with data.

Question 2

What does DDL stand for and what keywords are associated with it?

Answer 2

Data Definition Language: CREATE, ALTER, DROP. Used to change the structure of the database.

Question 3

What does DCL stand for and what keywords are associated with it?

Answer 3

Data Control Language: GRANT, REVOKE. Used to grant or revoke permissions for people.

Question 4

Name five common SQL keywords.

Answer 4

1. SELECT
2. FROM
3. WHERE
4. ORDER BY
5. GROUP BY (only used with aggregate functions)

Question 5

Write a common SQL statement with Select, From, Where keywords.

Answer 5

SELECT * (columns)
FROM Employee (database.table if you want to specify the database)
WHERE Salary > 50000; (condition)

Question 6

What is the default keyword for the ORDER BY?

Answer 6

asc not desc (ascending not descending)

Question 7

What are aggregate keywords (functions)? Name five.

Answer 7

Perform something on a set of data but only return a single value. Used with the SELECT keyword (columns).

1. COUNT
2. MAX
3. MIN
4. AVG
5. SUM

Question 8

What keywords are used to join tables?

Answer 8

JOIN, INNER JOIN (default), OUTER JOIN, LEFT OUTER JOIN, RIGHT OUTER JOIN

Question 9

What are the three SQL statement types?

Answer 9

1. Data manipulation language (DML)
2. Data definition language (DDL)
3. Data control language (DCL)