Relational Databases Lee Rudd Abstract Data for our programs are stored in various formats. The most commonly used format is in the form of a database since databases are not dependent on a single program or hardware platform. These databases are stored in five structures of hierarchical‚ network‚ relational‚ multidimensional‚ and object-oriented. Hierarchical structure organizes data in a one to many relationship. The network goes of the hierarchical structure by organizing data in
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there has been a controversial issue dealing with building a national DNA database. This issue has been brought up over the discussion of the actual database and what kinds of effects will come out of it‚ if it actually happens to go through. Some people think the database will be a force in crime fighting. Others think it is a violation of civil liberties. In the early 1900s‚ “fingerprinting‚” a new crime-fighting database‚ was developed. With the exception of identical twins‚ no two people have
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University of Greenwich Database assignment2 Iago Castro Cuna Student ID: 000628811 Course ID : COMP1450 DATABASE ASSIGNMENT2 Iago Castro Cuna Table of Contents 1 INTRODUCTION ..................................................................................................................... 4 2 CREATING THE DATABASE TABLES ....................................................................................... 5 2.1 Creating the company .........................................
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1. Advantages of database over Advantages of spread sheets; One of the advantages of database is that it reduced data redundancy this is because in databases‚ there is an identifier. The identifier is the primary key‚ where when it is entered‚ all other details‚ which saved under the primary key‚ will be revealed. Therefore‚ there’ll be less repetition of data. Next‚ databases improved data integrity‚ which it will guaranteed the data proven to be correct. Linked to the primary key function‚ the
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I learnt the core values of focus‚ perseverance and patience at a very early stage of my life. My father who is a patient‚ disciplined and determined individual‚ would spend countless number of hours in his endeavor to purchase a residential property in the nascent economic times of 1985 in India. His success in buying our dream home and at a “value-for-money” motivated me to follow his ideals. A few years later‚ it was this belief that led me to major success in organizing a cultural/religious event
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studies &research Information technology department Database systems Report on: (Comparison between Relational database & object oriented database) By: Mohammed Hussein Mahmoud Mustafa khedr To: Dr. Saad Darwish Introduction A database is a means of storing information in such a way that information can be retrieved from it. Thus a database is typically a repository for heterogeneous but interrelated pieces of information. Often a database contains more than one table. Codebooks and dictionaries
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DATABASE SPECIFICATIONS 1. TABLE NAME : TBLGENDER FIELD NAME DATA TYPE SIZE CONSTRAINT REFERENCES GID IntN/A PK‚ IDENTITY NONE GDESC Varchar6 NOT NULL NONE 2. TABLE NAME: TBLGRDLVL FIELD NAME DATA TYPE SIZE CONSTRAINT REFERENCES GRDID IntN/A PRIMARY KEY‚IDENTITY NONE GRDLVLDESC VarChar15 NOT NULL NONE GRDSECTION Varchar15 NOT NULL NONE 3. TABLE NAME: TBLRANK FIELD NAME DATA TYPE SIZE CONSTRAINT REFERENCES RANKID IntN/A PRIMARY KEY‚IDENTITY NONE RANKDESC Varchar20 NOT NULL NONE 4.
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The entity-relationship model (or ER model) is a way of graphically representing the logical relationships of entities (or objects) in order to create a database. entity type is a collection of entity instances sharing similar properties Strong Entity Vs Weak Entity An entity set that does not have sufficient attributes to form a primary key is termed as a weak entity set. An entity set that has a primary key is termed as strong entity set. A weak entity is existence dependent. That is the
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SYSTEM CONCEPTS A system can be simply defined as a group of interrelated or interacting elements forming a unified whole. Many examples of systems can be found in the physical and biological sciences‚ in modern technology‚ and in human society. Thus‚ we can talk of the physical system of the sun and its planets‚ the biological system of the human body‚ the technological system of an oil refinery‚ and the socioeconomic system of a business organization. A system is a group of interrelated components
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Oracle Table Triggers Version 11.1 General Data Dictionary Views Related To DDL Triggers trigger$ dba_triggers all_triggers user_triggers System Privileges Related To Table Triggers create trigger create any trigger administer database trigger alter any trigger drop any trigger Table Trigger Firing Options -- before constraints are applied BEFORE INSERT BEFORE UPDATE BEFORE DELETE -- after constraints are applied AFTER INSERT AFTER UPDATE AFTER DELETE Transaction
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