DBMS

A DBMS (Database Management System ) is a software that allows creation, definition, and manipulation of the database. Dbms is actually a tool used to perform any kind of operation on data in the database. …

Types of Database Architecture Understanding DBMS Architecture A Database Management system is not always directly available for users and applications to access and store data in it. A Database Management system can be centralised(all the data …

E.F Codd was a Computer Scientist who invented Relational model for Database management. Based on relational model, Relation database was created. Codd proposed 13 rules popularly known as Codd’s 12 rules to test DBMS’s concept …

A Relational Database management System(RDBMS) is a database management system based on relational model introduced by E.F Codd. In relational model, data is represented in terms of tuples(rows). RDBMS is used to manage Relational database. …

Database Keys Keys are very important part of Relational database. They are used to establish and identify relation between tables. They also ensure that each record within a table can be uniquely identified by combination …

Normalization of Database Database Normalisation is a technique of organizing the data in the database. Normalization is a systematic approach of decomposing tables to eliminate data redundancy and undesirable characteristics like Insertion, Update and Deletion …

ER-Diagram is a visual representation of data that describes how data is related to each other. Symbols and Notations Components of E-R Diagram The E-R diagram has three main components. 1) Entity An Entity can …

Introduction to SQL Structure Query Language(SQL) is a programming language used for storing and managing data in RDBMS. SQL was the first commercial language introduced for E.F Codd’s Relational model. Today almost all RDBMS(MySql, Oracle, …

create command create is a DDL command used to create a table or a database. Creating a Database To create a database in RDBMS, create command is uses. Following is the Syntax, create database database-name; …

alter command alter command is used for alteration of table structures. There are various uses of alter command, such as, to add a column to existing table to rename any existing column to change datatype …

SQL queries to Truncate, Drop or Rename a Table truncate command truncate command removes all records from a table. But this command will not destroy the table’s structure. When we apply truncate command on a …

DML command Data Manipulation Language (DML) statements are used for managing data in database. DML commands are not auto-committed. It means changes made by DML command are not permanent to database, it can be rolled …

TCL command Transaction Control Language(TCL) commands are used to manage transactions in database.These are used to manage the changes made by DML statements. It also allows statements to be grouped together into logical transactions. Commit …

Data Control Language(DCL) is used to control privilege in Database. To perform any operation in the database, such as for creating tables, sequences or views we need privileges. Privileges are of two types, System : …

Where clause is used to specify condition while retriving data from table. Where clause is used mostly withSelect, Update and Delete query. If condititon specified by where clause is true then only the result from …