UNIT 2: CHAPTER 7

STORING ORGANIATIONAL INFORMATION – DATABASES

Core component of any system which is DATABASE maintains information about various type of objects (inventory), event (transactions), people (employees), and places (warehouse). While, DATABASE MANAGEMENT SYSTEM (DMS) creates, read, updates, and delete data in database while controlling access and security.

Two primary tool for retrieving information from DBMS is QUERY-BY-EXAMPLE (QBE) TOOL helps users graphically design the answer to a question against a database. Secondly, STRUCTURED QUERY LANGUAGE (SQL) that asks user to write lines of code to answer questions against a database.

Database models is:

Hierarchical database model

Information organized into a tree-like structure (using parent/child relationship) in mean time, it cannot have many relationship.

Network database model

Flexible way of representing objects and their relationship.

Relational database model

Stores information in form of logically related two-dimensional tables.

ENTITY (TABLE) stores information about a person, place, thing, transaction, or event.

ATTRIBUTE (COLOMNS) are data elements associated with an entity.

PRIMARY KEYS is a field (or group of field) that uniquely identifies given entity in a table.

FOREIGN KEYS is a primary key of one table that appears an attribute in another table and acts to provide a logical relationship among the two table.

Advantages of database from business perspective:

1. Increased flexibility
2. Increased scalability and performance
3. Increased information integrity (quality)
4. Increased information security
5. Reduced information redundancy

DATABASE MANAGEMENT SYSTEM (DBMS) is software which users and application programs interact with database.

DATA-DRIVEN WEB SITES is interactive web sites that constantly updated and relevant to the needs of its customers through the use of database.

Data-Driven Web Site Business Advantages

Development which allows web sites owner to make changes at any time without rely on developer or knowing HTML programming.

Content management which require programmer to make updates.

Future expandability by enables site to grow faster than would be possible with a static site.

Minimizing human error a well-designed, data-driven web site will have “error trapping” mechanisms to ensure that required information is filled out correctly and that content is entered and displayed in its correct format.

Cutting production and update costs where data-driven web site can be updated and ‘published’ by any competent data entry or administrative person.

More efficient with data-driven solution, the system keeps track of the templates, so users do not have to.

Improved stability with data-driven web sites, there is peace of mind, knowing the content is never lost – even if your programmer.

Integrating Information among Multiple Databases

INTEGRATION allows separate systems to communicate directly with each other.

Forward integration means takes information entered into given systems and sends it automatically to all downstream systems and processes.

Backward integration means takes information entered into given system and sends it automatically to all upstream systems and processes.