Database Management Systems DBMS | CSC-351/621

Getting Started and Quick Overview

Motivation According to Glassdoor, the average salary for SQL Developer is $98,313 per year in the United States According to Glassdoor, the average salary for PHP Developer is $89,774 per year According to TIOBE, the software quality company, the SQL Language is one of the highest positions (since 2002) – December, 2018 According to TIOBE, the software quality company, the PHP Programming Language is one of the highest positions (since 2002) – December, 2018

Title and content layout with chart And it continues to rise - https://www.tiobe.com/tiobe-index/

Course Overview Relational Databases (since 1970) Entity Relationship Diagram (ERD) / Database Modeling SQL: CRUD queries, views, procedures, and triggers Cloud Computing (Microsoft Azure) – MS SQL Server Database Management Systems (DBMS) Web Applications: HTML, CSS, and PHP NoSQL: MongoDB – document-oriented database program

Course Goals and Objectives To develop an understanding of Relational Databases (SQL, and ERD Modelling) To develop an understanding of advanced concepts of Relational Databases To develop an understanding of NoSQL Databases Basic structure of web application and how a web browser interacts with a web server. Request-Response Cycle that is the basis of the Hypertext Text Transfer Protocol (HTTP) Final project – Web App that integrates with DB server

What is a Database?

What is a Database? A collection of individual data items Stored in a highly structured way Represents a model of reality Organizes the data in a way that facilitates efficient access to the information captured in the data Data can be stored in a single location Or, distributed across large networks

CRUD Tasks Create Read Update Delete All performed by a database engine

What is Database Management Systems?

Simplified - DBMS A database management system (DBMS) is a system software for creating and managing databases The DBMS provides users and programmers with a systematic way to create, retrieve, update and manage data Happy Coding!

Database Management Systems (DBMS) Server-based systems such as SQL Server or Oracle A system that communicates with the database server to perform CRUD operations Creation of databases Insertion, storage, retrieval, update, and deletion of the data stored in the database Maintenance of databases (i.e., backup, user permissions/control)

Relational Database Management Systems Being specific about what database management system we are using Database systems may vary, from relational (i.e., MySQL, T-SQL) to document- oriented databases such as MongoDB

System Categories Major server DBMS vendors Microsoft SQL Server (MSSQL) Oracle DB2 (IBM) PostgreSQL (open source, free to install and use) MySQL (open source, free to install and use)

What is SQL? Structured Query Language Used by the DBMS to interact with the database Create new tables Insert and update data Retrieve information A very beautiful and simple language!

Initial Terminology Data – facts that are recorded and can be retrieved/accessed Data formats – text, numbers, figures, audio/video, recordings and more Data is saved and kept because it is considered to be of use to an intended user

Initial Terminology Metadata – data that describes the structure and prosperities of the data Metadata is essential for the proper understanding and use of the data Data without metadata

Initial Terminology Data with metadata

Initial Terminology Database metadata – represents the structure of the database Database content that is not the data itself (data about the data) Contains: Names of the data structures Data types Data descriptions Other information describing the characteristics of the data

Initial Terminology Typical database system architecture

We will talk about that in more details later on in this course… Initial Terminology Front-end application – provide a mechanism for easy interaction between the user and the DBMS * DML (Data Manipulation Language) Manipulate data itself it is used to retrieve, modify/update, delete, and insert * DDL (Data Definition Language) It is used to define data structures (e.g., create table, alter table) In other words, it is used to create and modify the structure of database objects in the database (design) We will talk about that in more details later on in this course…

Initial Terminology Queries: access different parts of data and formulate the results of a request Transactions: symbolizes a unit of work performed within a system against a databases A single unit of logic or work SQL select statement and its result – Wikipedia

Steps in the Development of Database Systems

Steps in the Development of Database Systems Requirements collection, definition, and visualization Results in the requirements specifying which data the future database system will hold and what the capabilities and functionalities of the database system will be The collected requirements should be clearly defined and stated in a written document, and then visualized Conceptual database model – a visualization of requirements by using a conceptual data modeling technique (such as entity-relationship diagram (ERD))

Steps in the Development of Database Systems Iterative nature of the database requirements collection, definition, and visualization process

Steps in the Development of Database Systems Database modeling (logical database modeling) – creation of the database model that is implementable by the DBMS Logical database modelling follows conceptual database modelling Database implementation – using a DBMS to implement the database model as an actual database Most modern databases are implemented using a relational DBMS (RDBMS) software

Steps in the Development of Database Systems Developing front-end applications – designing and creating application for indirect use by the end-users Front-end applications are based on the database model and the requirements specifying the front-end functionalities Front-end applications contain interfaces (such as forms and reports) accessible via a navigation mechanism (such as menu/navigation bar)

Steps in the Development of Database Systems Database deployment – releasing the database system for use by the end users Database use – the insertion, modification, deletion, and retrieval of the data in the database system

Steps in the Development of Database Systems Database administration and maintenance – performing activities that support the database end user, including dealing with technical issues, such as: Providing security for the information contained in the database Ensuring sufficient hard/solid drive space for the database content Implementing the backup and recovery procedures

People Involved w/ DB Systems Database analysts, designers, and developers Database admins – perform the tasks related to the maintenance and administration of a database system Database engineers/designers (a.k.a architects) – involved in the database modeling stage Database developers – in charge of implementing the database model as a functioning database using the DBMS software Database developers are involved in SQL Programming language Write SQL queries, procedures, triggers, and so on

Additional DBMS Functionality DBMS may additionally provide Protection or security measure to prevent unauthorized access “Active” processing to take internal actions on data Maintenance of the db and associated programs