Relational Databases presentation (MySQL)

This presentation is about "Relational Databases presentation (MySQL)"

1. Relational Databases
Student: Sadyk Abdyreshit
Group: 4711

2. A relational database is a type of database that
organizes data into tables called relations.
•Each table consists of rows (records) and columns
(fields).
•This model was introduced by Edgar F. Codd in
1970.
•Relational databases are widely used for
structured data storage and management.

3. 1.Tables: Store data in rows and columns.
2.Primary Key: A unique identifier for each row
in a table.
3.Foreign Key: A field in one table that links to
the primary key in another table.
4.Indexes: Improve query performance.
5.Schemas: Define the structure of tables and
relationships.
Components of a Relational Database

4. Relational Data Model

Relations are stored in tables
e.g. Sponsor(Name,Bill)
Sponsor
Name Bill
Bahbit Tax
Sulgun Defense
Serdar Defense
Palwan Commerc
e
Atrributes
Tuples

5. Schemas

A relation schema is a relation name
and a list of attributes
Sponsor(Name,Bill)

A database is a collection of relations

A database schema is the set of all the
relation schemas in the database

6. Converting from Entity-
Relationship Model

ER: Entity set -> relation
ER Attributes become Relational attributes

ER: Relationship -> relation
Keys of connected ER entity sets become
Relational attributes

7. 
Senator(Name,Party,State,Years)

Bill(Name,Text)

Lobbyist(Name,Organization)
Senator
Name
State
Party
Years
Name Text
Bill
Name
Organization
Lobbyist

8. ER Relationships
Senator
Name
State
Party
Years
Name Text
Bill
Sponsored
Name
Organization
Lobbyist
Wrote
Contributed

9. Relations

Sponsored(Senator,Bill)

Wrote(Bill,Lobbyist)

Contributed(Senator,Lobbyist)

Remember, each of these is expressed as a
table (with the columns given by the
“parameters”)

Notice that columns can refer to “bigger”
items, with even more attributes