Database - maintains information about various types of objects (inventory), events (transactions), people (employees), and places (warehouse).
Database models :
Hierarchical database model - information is organized into a tree-like structure (using parent/child relationship) in such a way that it cannot have too many relationship.
Hierarchical database model - information is organized into a tree-like structure (using parent/child relationship) in such a way that it cannot have too many relationship.
Network database model - a flexible way of representing objects and their relationships.
Relational database model - stores information in the form of logically related two-dimensional tables.
Entities and Attributes :
Entities is a person, place, thing, transaction, or event about which information is stored. The rows, in each table contain the entities.
Entities and Attributes :
Entities is a person, place, thing, transaction, or event about which information is stored. The rows, in each table contain the entities.
Attributes (fields, columns) is characteristics or properties of an entity class. The columns in each table contain the attributes.
Keys and Relationship :
Primary key - a field (or group of fields) that uniquely identifies a given entity in a table.
Keys and Relationship :
Primary key - a field (or group of fields) that uniquely identifies a given entity in a table.
Foreign key - a primary key of one table that appears an attribute in another table and acts to provide a logical relationship among the two tables.
Relational Database Advantages :
Increased flexibility - a well-designed database should handle changes quickly and easily and provide users with different view.
Relational Database Advantages :
Increased flexibility - a well-designed database should handle changes quickly and easily and provide users with different view.
Increased scalability performance - scalability refers to how well a system can adapt to increase demands. And performance is to measures how quickly a system performs a certain process or transaction.
Reduced information redundancy - redundancy is the duplication of information or storing the same information in multiple places.
Increased information integrity (quality) - information integrity is to measures the quality of information. And the integrity constraint is the rules that help ensure the quality of information. Relational integrity constraint and business-critical integrity constraint.
Increased information security - password provides authentication of the user,access level determines who has access to the different types of information, and access control determines types of user access, such as read-only access.
Database Management Systems :
Software through which users and application programs interact with a database.
Database-Driven Websites :
An interactive website kept constantly updated and relevant to the needs of its customers through the use of a database.
Integrating Information among Multiple Databases :
Integration is allows separate systems to communicate directly with each other. there has two ways is -forwards integration is takes information entered into a given system and sends it automatically to all downstream systems and processes. then, backward integration is takes information entered into a given system and sends it automatically to all upstream systems and processes.
Database Management Systems :
Software through which users and application programs interact with a database.
Database-Driven Websites :
An interactive website kept constantly updated and relevant to the needs of its customers through the use of a database.
Integrating Information among Multiple Databases :
Integration is allows separate systems to communicate directly with each other. there has two ways is -forwards integration is takes information entered into a given system and sends it automatically to all downstream systems and processes. then, backward integration is takes information entered into a given system and sends it automatically to all upstream systems and processes.
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