SQL Basic Concept (10 10 2021) - kucmoving/SQL-learning GitHub Wiki

SQL(Structured Query Language)

Function:

• Relational database management, data manipulation
• Read, retrieve, write, update

Fearture:

• Not Complete application
• Simple but powerful

Database Adminstrator

• Manage database
• Permissions to users
• Create and manages tables
• Uses SQL to query and retrieve data

Data Scientist

• End user of a database
• Uses SQL to query and retrieve data

DBMS

• Each DBMS has it own langauge
• Example: miscrosoft SQL Server, MySQL, IBM DB2 Oracle, Sybase ASE, PostgreSQL, SQLite, MySQL…

Data Modelling

• Organizes information into multiple, related tables
• Shows relationship between business process

Relational Model:

• Easy querying, manipulating

Transactinal Model

• perational database(e.g. healthcare)

Relationship(example)

• One to many: customer to invoices
• Many to many: student to classes
• One to one: : manager to store