Introduction to Transaction
INTRODUCTION TO TRANSACTION A transaction can be defined as a group of tasks. A single task is the minimum processing unit which cannot be divided ...
Read moreWhat is computer network
COMPUTER NETWORK: Computer network is defined as a set of interconnected autonomous systems that facilitate distributed processing of information. Computer network is an interconnection of ...
Read moreRelationship among entities
RELATIONSHIP AMONG ENTITIES Relationship A relationship is represented by diamond shape in ER diagram, it shows the relationship among entities. There are four types of ...
Read moreEntity
ENTITY AND ATTRIBUTE ENTITY An entity is an object or component of data. An entity is represented as rectangle in an ER diagram. For example: ...
Read moreSQL Functions
SQL FUNCTIONS Five Important aggregate functions are SUM, AVG, MIN, MAX and COUNT. They are called aggregate functions because they summarize the results of a ...
Read moreCheck Constraint
CHECK CONSTRAINT The CHECK constraint is used to limit the value range that can be placed in a column. The CHECK constraint allows only certain ...
Read morePrimary and Foreign key
PRIMARY KEY AND FOREIGN KEY Primary Key: A primary key is a field in a table which uniquely identifies each row in a table. Primary ...
Read moreSQL join
SQL JOIN A SQL Join statement is used to combine data or rows from two or more tables based on a common field between them. ...
Read moreIntroduction to Data Models
INTRODUCTION TO DATA MODELS In DBMS data models define how the logical structure of a database is modeled. Data models define how data is connected ...
Read moreDDLDMLDCL
SQL | DDL, DML, DCL COMMANDS Structured Query Language(SQL) is the database language which is used to perform certain operations on the existing database and ...
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