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
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