Kevin Mitra
CMPS 3680
HW #7

1. A type of database which uses a structure that allows us to identify and access data in relation to another piece of data in the database.

2. An SQL is a standard language for dealing with Databases which used to insert, search, update and delete records.

3. Is used to model the logical view of the system from data perspective which therefore, it describes the structure of a database with a diagram known as Entity Relationship Diagram.

4. - One-to-one relationship: is a type of cardinality that refers to the relationship between two entities A and B where an element of A can only be linked to an element of B.
   - One-to-many relationship: is a type of cardinality where elements A and B, therefore, element of A can be linked to many elements of B, but a member of B is linked to only one element of A.
   - Many-to-many relationship: is a type of cardinality where A and B are known as entities, therefore, A may contain a parent instance for there are many children in B.

5. the main purpose of a primary key is to implement a relationship between two tables in a relational database. The reason shy it should be unique because the primary key is the target for specific records.

6.