WEEK 5

Question 1

Question: What is the CREATE TABLE command used for in SQL?

Answer 1

Answer: The CREATE TABLE command is used to create a table in SQL. It requires a table name, names for all columns, data type for each column, and applicable constraints.

Question 2

Question: What are some data types used in SQL?

Answer 2

Answer: Some data types used in SQL are:

Numeric: INT, DECIMAL(L,D)
Character/String: CHAR(L), VARCHAR(L)
Date/Time
Boolean (Yes/No)
GUID

Question 3

Question: What is a constraint in SQL?

Answer 3

Answer: In SQL, a constraint is a restriction on a column to ensure data integrity. Examples of constraints are PRIMARY KEY, UNIQUE, NOT NULL, CHECK, and FOREIGN KEY.

Question 4

Question: What is the purpose of the NOT NULL constraint in SQL?

Answer 4

Answer: The NOT NULL constraint in SQL ensures that a column does not accept null values.

Question 5

Question: What does the UNIQUE constraint do?

Answer 5

Answer: The UNIQUE constraint assigns a value to an attribute when a new row is added to a table.

Question 6

Question: What is the purpose of the DEFAULT constraint?

Answer 6

Answer: The DEFAULT constraint validates data when an attribute value is entered.

Question 7

Question: What is the purpose of the CHECK constraint?

Answer 7

Answer: The CHECK constraint validates data when an attribute value is entered.