An Overview of Databases and Their Types - ProgrammerTech


An Overview of Databases and Their Types

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An Overview of Databases and Their Types

Database Concept

Databases are relational stores in which data is stored in tables of any size and is secure. Oracle is considered the most powerful database in terms of protection. Simply put, the Database is a large file in which the information we want to store can be arranged in an orderly and organized manner, and this information can be retrieved and modified at any time.

Today we will start by explaining the introduction of new lessons in Oracle databases, which are considered the most powerful databases in terms of security and support several programming languages ​​such as (Java, C, C#, C++) and others. The database is denoted by the icon of a cylindrical shape because it is intended to be a repository of information, and the database is the most important element in projects. Most programs, websites, and huge systems use databases to store the information that users save in them, and there are many types of databases, including (MySQL, SQL Server, Oracle, Access, SQLlite) and many others.


Database Course Catalog

  1. Database Concept.
  2. Types of database management systems.
  3. Relational databases.
  4. Dealing with relational databases.
  5. Learn the language of inquiries, their sections, and their commands.
  6. Install and delete the program.
  7. How the password works and how a new user works.
  8. Create tables and perform all commands related to these tables such as deleting, adding, modifying...etc.
  9. Create scenes, triggers, stored procedures, and strings.
  10. How to link SQL/Plus databases with any other language.


Types of database management systems

  1. Hierarchical databases: This system is often used with old computers.
  2. Network Database: This type appeared after hierarchical databases after the great expansion of network systems. But he faced many difficulties in understanding the nature of dealing with data as in the hierarchical system.


Relational Databases

Relational Database This system on which most database programs such as Oracle depend, because it is one of the most powerful database systems for its superior ability to absorb large amounts of data without affecting performance in terms of speed and accuracy, and this system is characterized by confidentiality and security Because it contains a system of giving powers to its users and for ease of use and building applications.

Databases sql server


Query Language (SQL)

The term SQL stands for Structured Query Language, and it is a language used to issue all commands related to the database. This language is divided into five main sections, through which commands can be issued for each section.

Data Retrieveal command

  • SELECT: A command to display data from a table or object.

Command (DML) Data Manipulation Language

  • INSERT: The command to add data to the database.
  • UPDATE: The command to update and modify tables.
  • DELETE: A command to delete the data of a table or an object and is not used to delete the entire table.

Command (DDL) Data Definition Language

  • CREATE: The command to create a table, scene, procedure, user, or any object in the database.
  • Alter: A command to modify a table, viewer, stored procedure, or other object in the database.
  • DROP: A command used to delete a table or an object that can delete the entire table.
  • RENAME: command to rename a table or another.

Transaction Control

  • COMMIT: to install data in the table to confirm saving or modification.
  • ROLLBACK: To undo the data installation or restore the table that was deleted by the (Drob) command.
  • SAVEPOINT: To return to a specific point somewhere in the database.

Command (DCL) Data Control Language

  • GRANT: Give users permission to access data.
  • REVOKE: To withdraw permissions from users.

Wazeer Almuliky

Wazeer Almuliky

شاب يمني من صنعاء بكلريوس تقنية معلومات مهندس قطع إلكترونية و مبرمج تطبيقات اندرويد, خبرة في قواعد البيانات و الجافا, أهتم في الاكترونيات و لغات البرمجة منها فلاتر والجافا وسي شارب