DBMS-simulator-using-BASH-scripting

The project’s purpose is to build a Database Management System with its tasks using Bash Scripting.

Project Discription:

A bash project that simulate the MySQL database and do the following: When A user run it the screen will be cleared and ask for the below entry and need to be selected by it’s number Each one will run a specific script.

• Create Database user.
• Delete Database User.
• Create new Database.
• Delete an existing Database.
• Create A new Table inside Database
• Insert A New Row in a Table
• Select Data from Table

Project Steps:

The Project will be under Directory Called MySQL.

There will be a main script called MySQL/main.sh.

1) Create Database user

• By default, will be a system user called “oracle”
• If the user that run the script is “oracle” or an admin user then he can do the following:
  • Will Ask you for a new admin user.
  • If this user already exists MSG will appear that tells the user is already exist.
  • If not, the entered user will be in a file called DB_admins.db.
  • DB_admins.db will have a list of admin users, including oracle and other created users.

2) Delete Database User

• Only users in DB_admins.db can run this script.
• The Script will show you the list of users in DB_admins.db.
• If one is selected then it will be deleted from DB_admins.db.

3) Create new Database

• Only users in DB_admins.db can run this script.
• The script will ask you for database name.
• Then A Directory is created with the entered DB name under the Following Path: MySQL/DataBases/YOUR_NEW_DB.
• A file will be in this path called owner.txt will have the user name for the user that create this database.
• The final output for this script is a directory with DataBase Name.

  MySQL/DataBases/EmplyeeDB

4) Delete an existing Database

• Only users in DB_admins.db can run this script.
• The script will show all available created Databases inside MySQL/DataBases
• If the Database owner is the same with the user that run this script, then Database directory and it’s content be deleted.

  if EmplyeeDB is selected directory and it’s content be deleted.

5) Create A new Table inside Database

• Only users in DB_admins.db can run this script.
• The script will show all available created Databases inside MySQL/DataBases.
• If the Database owner is the same with the user that run this script, then will ask you for Table Name, Number of columns need to be created.
• If Table Name not already exist inside this Database then will ask you to enter the Column Names according to the entered number of columns.
• The final output for this script must create a file named with the entered Table Name.

MySQL/DataBases/EmplyeeDB/employee.table:
#cat employee.table
emp_id,emp_name,job_name,manager_id,hire_date

• Each Column name is separated by comma.

6) Insert A New Row in a Table

• Only users in DB_admins.db can run this script.
• The script will show all available created Databases inside MySQL/DataBases to select your working database.
• If the selected Database owner is the same with the user that run this script, then will show all available tables inside this database to select from it.
• For the selected Table The script will start reading the table header then will ask you to enter these data.
• First column must be always unique.

7) Select Data from Table

• The script will show all available created Databases inside MySQL/DataBases to select your working database.
• Then will show all available tables inside this database to select from it.
• Now you will have two options:
  • Show The content of the selected table will be shown by cat this table name.

  #cat employee.table
  emp_id,emp_name,job_name,hire_year
  1,Mohamed,unix admin,2021
  2,Ahmed,unix admin,2016
  3,Ahmed,DBA,2019

  • Search inside table take a string then show you the rows that have this string.

8) Delete Row from Table

• From the selected table each row the contain a specific string must be deleted.
• Then show you the updated table.

Tools and Technologies:

• Bash/Shell Scripting.
• Linux RedHat.
• PuTTY.
• Virtual Machines.