[Database] #1 SQL?

SQL Tutorial - Full Database Course for Beginners - YouTube

 

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DBMS

- A special software program that helps users create and maintain a database

- create, read, update, delete

- user tell dbms to do those thing 

 

Relational Database (SQL)

- Organize data into one ore more tables

  - each table has columns and rows

  - A unique key identifies each row

 

Non-Relational (no SQL / not just SQL)

- Organize data is anything but a traditional table

  - Key-value stores

  - Documents (JSON, BLOB, ..)

  - Graphs

  - Flexibel Tables

 

Relational Database Management Systems (RDBMS)

- mySQL, Oracle, postgreSQL, mariaDB

 

Non-Relational Database Management Systems (NRDBMS)

- mongoDB, dynamoDB, apache cassandra, firebase ...

 

Structured Query Language (SQL)

- Standardized language for interacting with RDBMS

 

 

primary key (unique id)

- should be unique in a table

 

foreign key

- stores ids of other tables

composite key

- need two attribute.

 

Structured Query language (SQL)

- is a language used for interacting with RDBMS

- implementations can be vary between systems

- can do 4 types of roles

  - Data Query Language

  - Data Definition Language

  - Data Control Language

  - Data Manipulation Language

 

Queries

- a set of instructions given to RDBMS

- Goal is to only get the data you need