Week 6

Question 1

What is the UNIQUE Constraint in MySQL?

Answer 1

Ensures values in a column or group of columns are different

Question 2

What is the CHECK Constraint in MySQL?

Answer 2

Ensures that values stored in a column or group of columns satisfy a Boolean expression

Question 3

What is the NOT NULL Constraint in MySQL?

Answer 3

Ensures values in a column or a group of columns are different

Question 4

What is a Foreign Key (Constraint)?

Answer 4

Refers to Primary Key in another table

Is a column or set of columns used to establish a link between the data in two tables. These columns must match the columns in the referenced table (the parent table) and must have the same data type

Question 5

What are Constraints in MySQL?

Answer 5

SQL Constraints are rules applied to columns in a table to ensure data integrity and consistency

They help to define the type of data that can be inserted into a table and prevent invalid data

Question 6

What is a Primary Key (Constraint)?

Answer 6

Implicitly means NOT NULL + UNIQUE

A table can have one and only one primary key