Basic Concepts of Database

What is a Database (DB)?

-       Any collection of related information

• Phone Book
• Shopping list
• Todo List
• Your 5 best friends 
• Facebook’s User Base

 

-       Databases can be stored in different ways 

• On paper
• In your mind 
• On a computer
• PowerPoint slides
• Comments section

 

*Computers + Databases > extremely useful

·      computers are great at keeping track of large amounts of information

·      Amazon.com vs shopping list

 

Database Management System (DBMS)

: a special software program that helps users create and maintain a database

• Makes it easy to manage large amounts of information 
• Handles security 
• Backups
• Importing/exporting data
• Concurrency
• Interacts with software applications: programming languages

 

Two Types of Databases

1.     Relational Databases: SQL (most popular, organize all the data into a pre-defined table and insert info after that)

-       organize data into one or more tables 

• Each table has columns and rows
• A unique key identifies each row

 

2.     Non-Relational: noSQL / not just SQL (alike excel spread sheet)

-       Organize data in anything but a traditional table

• Key-value stores: html, JavaScript 
• Documents: JSON, XML, etc
• Graphs
• Flexible Tables

 

Relational Databases (SQL)

1.     Relational Database Management Systems (RDBMS)

-       help users create and maintain a relational databae 

ex > mySQL, Oracle, PostgreSQL, MariaDB, etc.

 

2.     Structured Query Language (SQL)

-       Standardized language for interacting with RDBMS 

-       Used to perform C.R.U.D operations, as well as other administrative tasks (user management, security, backup, etc).

-       Used to define tables and structures

-       SQL code used on one RDBMS is not always portable to another without modification 

 

Non-Relational Databases (noSQL, not just SQL)

            *JSON: html, most popular in noSQL

 

1.     Non-Relational Database Management Systems (NRDBMS)

-       Help users create and maintain a non-relational database

• MongoDB, DynamoDB, apache Cassandra, firebase, etc

 

2.     Implementation Specific

-       Any non-relational database falls under this category, so there’s no set language standard

-       Most NRDBMS will implement their own language for performing C.R.U.D and administrative operations on the database.

*cause there’s no language operating non-relational database

 

Database Queries

: requests made to the database management system for specific information

-       It grabs information I want in a large database via programming language 

-       As the database’s structure become more and more complex, it becomes more difficult to get the specific pieces of information we want 

-       Query is alike a google search; we type specific programming language in query instead of English for a google search. 

 

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Reference  

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