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Database is a aggregation of related informations storage together, these informations is structured, no harmful or unneeded redundancy, and for different sorts of application services ; Data storage independent processs, the usage of it. Insert the new informations to the database, modify, and retrieval of original informations can be made by common and controlled manner. When a system exists in the specific database construction wholly independent, the system consists of a set of database. The 2nd definition of the database is database organisation harmonizing to some informations theoretical account and informations aggregation stored in the subsidiary storage. The information aggregation has the undermentioned characteristics: do n’t reiterate, to the best manner for a assortment of different application the services of a specific organisation, information construction is independent of usage it application, informations growing, delete, alteration and retrieval of the incorporate direction and control package. From the development of history, database information ‘s senior direction stage of the development of the file direction system.The first definition is purely talking, database is “ harmonizing to informations construction to form, storage and direction of informations warehouse ” . In the economic direction of the day-to-day work, frequently need to some informations “ warehouse ” and harmonizing to the direction needs correspondingly processing. For illustration, the basic state of affairs of the endeavors and establishments of the forces section should usually be unit staff ( employee Numbers, name, age, sex, topographic point of birth, rewards, recovery, etc. ) are stored in the tabular array, the tabular array can be regarded as a database. And this “ information warehouse ” we need any clip a trade brotherhood, wage can besides ask the figure of workers in an interval, and so on. If work can be automatically in the computing machine, our forces direction can accomplish really high degree. In add-on, fiscal direction, warehouse direction, production direction, to make a big figure of this “ database ” , so it can utilize the computing machine to recognize the finance, warehouse, production mechanization direction.

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Characteristics And The Advantages Computer Science... TOPICS SPECIFICALLY FOR YOU

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Answer of Question1

Primary key

A primary key, besides called give precedence to identify in a relational database system, each record a alone key. A relational database must ever hold a and merely a primary key. The chief key is frequently shown as listed in a relational database tabular array. A primary key in relational database pick frequently depends on decision maker penchants. May alter the given primary cardinal database, the user ‘s specific demand alterations. We need to take an appropriate primary key, it will merely tag each employee. Your first thought is to utilize the name of the employee. It wo n’t work good, because it can desire to see, you hired two employees of the same name. A better pick is the usage of a alone employees ID figure, assigned to each employee when they hired. Some organisations choose to utilize societal security figure ( or similar authorities identifier ) for this undertaking, because each employee has a and they are guaranteed to be alone.

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Foreign Key

A foreign key, besides known as the database table outside key from another tabular array ( or mark ) of a peculiar key, is normally the chief key tabular array, the usage of cardinal. The chief key could be the mark by many other off-balance sheets cardinal. But the Lord Key is non needfully a cardinal objective.It can alter the tabular array of the primary key ; alter the user ‘s specific demands. For illustration, when the people in the town may be the lone harmonizing to their driver ‘s license figure in an application, but in another state of affairs will be more convenient to find them harmonizing to their phone figure. When the tabular array of the primary key is to alter the, related external key Settings, if any, normally wo n’t alter. External cardinal mention bound in two tabular arraies. Designation of the external key row or column ( mention ) tabular array, refers to another ( mention ) set tabular array. Listed in the mention list must be the primary key or other campaigner cardinal mention list. In a line list value must look in a separate tabular array mentions. Therefore, in the mention list does non include the value does non be in the mention list ( except possibly is NULL ) . This method can besides be connected together of the mention information, it is of import to standardised database. In the mention list quoted more than a line in the tabular array refers to the same line. Most of the clip, it reflects a ( chiefly tabular array or mention list ) many ( sub list or mention list ) relationship.

Mention and mention list may be the same tabular array, external key mention back to the same tabular array. This external key is a known SQL: as a self-reference or recursive foreign key in 2003. A tabular array can hold multiple external key, each external key can hold different mention tabular array. Each external key is independent of database system. Therefore, the relation tabular array use external key cascade can be constructed.Let us suppose that section tabular array usage section name listed as the chief key. Create two tabular array, the relationship between the we add a new column employees table called section. Then we fill in the name, each staff subsidiary sections. We besides notice the database direction system, the section staff list is a foreign cardinal mention the section tabular array. The database will put to death mention unity, to guarantee that all the value in the section list of employees table have matching entries in the tabular array of the section.

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4.0 Relationship

You have a batch of household member ‘s relationship. For illustration, you and your female parent is related. You merely have one female parent, but she may hold several kids. You and your brothers and sisters relationship, you may hold a batch of brothers and sisters, and, of class, they will hold a batch of brothers and sisters. If you get married, you and your partner is a partner, each other, but merely one time. A relational database is really similar to the relationship between their tabular arraies. There are three types of relationships:

aˆ? 1 on a: Two tabular array merely one side of the relationship in the both sides of the record. Each primary cardinal value is merely relevant ( or non ) in the related records in the tabular array. They are like partner, you may or may non acquire married, but if you are, you and your partner is a partner. Most people a relationship, forced by concern regulations, non of course flow from the informations. For such a regulation, you can normally unite with Renee Cheng standardized regulations and did non go against a table two tabular array.

aˆ? One-to-many: The primary key tabular array contains merely a record, involves the nothing, one or more than in the related tabular array records. This relationship is similar to your parents. You merely have one female parent, but your female parent may hold several kids.

aˆ? Many-to-Many: each of the two a tabular array with the record can be any figure of records in another tabular array ( or no record ) . For illustration, if you have brothers and sisters, your brothers and sisters ( and there are many brothers and sisters. Many-to-many need the 3rd tabular array, as an helper or a linked list is known, because relationship system can non be straight fitting relationship.

And side when you build the relationship between tabular arraies, you may be really familiar with informations. Therefore, this association is more than at this point, you begin to acquire clear. Depends on your database system is the two tabular array to happen the value of the stage fiting relation between formation. When a lucifer is found, the system straight from two the informations in the tabular array to make a practical record. For illustration, you may desire to see all of the books are written by a specific writer. In this instance, the system will fit of the books and newspapers in between the value in the tabular array. It is of import to retrieve that most of the clip, the resulting record is dynamic, this means that their work record to a practical frequently come back for any alteration in the underside of the tabular array.

5.0 Primary key & A ; Foreign key table

This is a lecture table.Lecture Idaho is a primary key, so talk name is foreign key.

talk

Idaho

talk ID

talk Name

Course

Telephone figure

Centre ID

1

LC1201

Kama

CICT

012-3994943

CT11001

2

LC1202

mala

Dot

012-4893834

CT11002

3

LC1203

Kenny

Dot

012-1849384

CT11003

4

LC1204

kobo

DBM

012-9384984

CT11004

5

LC1205

Kio

DHM

012-4939949

CT11005

6

LC1206

doodly-squat

CICT

012-9428948

CT11006

7

LC1207

Kit

CICT

012-4938483

CT11007

8

LC1208

Johnson

Dot

012-9384839

CT11008

9

LC1209

Kiki

DHM

012-9849348

CT11009

10

LC1210

Flatness

Dot

012-9924834

CT11010

This is a pupil tabular array. Student Idaho is primary key, talk Idaho is foreign key.

Student

Idaho

Student ID

Student Name

Lecture ID

Cashier ID

Telephone figure

Course

4

IP092856

kooky

LC1204

CS105

016-9238339

DBM

8

IP097157

Dent

LC1908

CS208

016-3958855

Dot

3

IP110239

Jackson

LC1903

CS203

012-9846573

Dot

1

IP134787

KIMA

LC1901

CS201

013-2345678

DHM

9

IP413687

Henry

LC1909

CS209

016-1823823

DBM

7

IP824356

NICOLE

LC1907

CS207

016-3334321

DBM

6

IP865237

Sherry

LC1906

CS206

016-5449949

DHM

10

IP875276

KELVIN

LC1910

CS210

012-4959959

Dot

5

IP976458

JEFF

LC1905

CS205

016-2293839

Dot

2

IP981184

Matthew

LC1902

CS202

012-4949485

DHM

This is a teller table.Cashier Idaho is a primary key, pupil name is foreign key.

Teller

Idaho

Cashier ID

Cashier name

Student Name

Course

Fees Payment

Student ID

1

CS101

HAMI

KIMI

DHM

1500

IP092856

2

CS102

choping

Matthew

DBM

2000

IP098157

3

CS103

armada

BRENDON

Dot

3000

IP100239

4

CS104

height

KEN

DBM

3500

IP135687

5

CS105

Milo

JEFF

IE100

1000

IP413587

6

CS106

sheng

Sherry

CICT

2500

IP824356

7

CS107

foreigner

NICOLE

CICT

2500

IP865237

8

CS108

Xing

Dent

Dot

5000

IP874276

9

CS109

Hang

KENNY

CICT

2500

IP976456

10

CS110

Ahlen

KELVIN

Dot

5000

IP981124

This is halfway tabular array. Center Idaho is primary key, and so cashier Idaho is a foreign key.

Centre

Idaho

Centre ID

Lecture Name

Course

Cashier ID

1

CT10001

kamala

CICT

CS101

2

CT10002

Milo

Cat

CS102

3

CT10003

Kenny

Dot

CS103

4

CT10004

koi

DBM

CS104

5

CT10005

potassium nitrate

IE100

CS105

6

CT10006

Jackson

CICT

CS106

7

CT10004

Michel

DHM

CS107

38

CT10005

Johnson

Dot

CS108

9

CT10006

bibs

DBM

CS109

10

CT10017

flatness

Dot

CS110

6.0 Decision

The database can assist people, database for development in our hereafter. It will complete a series of complex informations ; it is easy to obtain the needful information. Computer database normally contains polymerisation of information records or files, such as gross revenues minutess, catalogue and stock list, and client files. A database is a connected to an point of informations aggregation, as a unit direction. For illustration, Microsoft Access places the whole database in a information file, so an Access database can be defined as files, including informations point.

Introduction Question2

DBMS A aggregation ofA programsA that enables you toA shop, modify, and extract information from aA database. There are many different types of DBMSs, runing from smallA systemsA thatA tally on personal to immense systems that run onA mainframe.

A DBMS is normally an built-in portion of a database merchandise. OnA PCs, Microsoft Access is a popular illustration of a single- or small-group user DBMS. Microsoft’sA SQL ServerA is an illustration of a DBMS that serves database petitions from multiple ( client ) users. Other popular DBMSs ( these are all RDBMSs, by the manner ) are IBM’sA DB2, A Oracle ‘s line of database direction merchandises, andA Sybase ‘s merchandises. IBM ‘s Information Management System ( IMS ) was one of the first DBMSs. A DBMS may be used by or combined withA transactionA directors, such as IBM ‘s Customer Information Control System ( CICS ) . DBMSs come in many forms and sizes. For a few hundred dollars, we can buy a DBMS for our desktop computing machine. For larger computing machine systems, much more expensive DBMSs are required. Many mainframe-based DBMSs are leased by organisations. DBMSs of this graduated table are extremely sophisticated and would be highly expensive to develop from abrasion. Therefore, it is cheaper for an organisation to rent such a DBMS plan than to develop it. Since there are a assortment of DBMSs available, when a user is utilizing the DBMS, they should cognize some of the basic characteristics, every bit good as strengths and failings, of the major types.

7.0 Answer of Question2

The chief Features and The Advantages of Relational Database

A relational database to hive away informations in the signifier of rows and columns users understands. This series of rows and columns are called list, incorporating a set of table database. The chief features of the relational database is to make a database, based on the relational theoretical account, set algebra and other mathematical constructs and methods to cover with the informations in a database. Different sorts of entities in the connexion between the existent universe and entity relationship theoretical account. Now the theoretical accounts have some unfavorable judgment, but it is still the traditional criterion informations storage. Opinion may be a subset of the informations, attention deficit disorder and simplify the multiple dealingss, dynamically hidden information complexness, cut down the informations storage demands. A relational database utilizing SQL, this is a simple, easy to understand linguistic communication. In the field of SQL bid instructions can be realized in the signifier of database. Most makers support database SQL criterion. Flat file competitory proficient supports stored in order of their informations, besides fail to supply user retrieval and ask the options.Standard informations question linguistic communication SQL is a linguistic communication based on relational database, this sort of linguistic communication executive informations retrieval in relational database and operation. The advantage of the relational database is fundamentally, relational database based on set theory. Standardization is an of import portion of a relational database theoretical account. Relational operators, relational database support, had better have standardized tabular array. A relational database support relational algebra, set theory to back up the relational operators. In add-on, from the mathematical set operation, brotherhood, intersection, extraordinary and Cartesian merchandise, relational database besides support choice, undertaking, the dealingss, the connexion and division operation. These actions are the lone relational database.

The Main Characteristics and the Advantages of Object Relational Database

The chief character is object database object relational database direction system ( so ) is defined as an incorporate database map and object-oriented scheduling linguistic communication map of a database direction system ( DBMS ) , face database object looks like one or more bing programming linguistic communication scheduling linguistic communications. Object mention of a lasting identifier ( PID ) , PID can unambiguously place a individual object, may be used to put up the dealingss between the grade and container objects. Face is besides strengthened the bag, support for heritage. Object oriented characteristics combination and traditional DBMS features, such as lock, protection, dealing processing, question, layout of the concurrence and persistent. Then in a little more than a user ‘s relentless memory client/server environment. Concurrent entree and so can manage object, lock and personal businesss protection, prevent all types of menace object memory, take attention of the traditional undertakings, such as backup and restore like. This is so face and relational database to hive away different because the object, instead than organize. Object relational database direction system, to back up object-oriented informations theoretical account ( hereinafter referred to as the “ OO theoretical account ) . Object-oriented database system is a lasting, shared object library storage and direction ; and an object set object library is defined as an object-oriented theoretical account. Object relational database direction system is a practical scheduling support modular design and package reuse. Program design activity focused on the connexion between object and object ( or communicating ) , so as to finish the computation. Object orientated plan is the same object set ( or communicating ) . Object-oriented scheduling is the basic thought of packaging and scalability. The advantages of the object relation database are reuse can be extended from the database waiter, so that focal point executive nucleus map, non in each application codification. The 2nd advantage is an illustration is a complex type ( or extended basic types ) defined in the database, but it is the many applications. After it was asked to specify this type in each application processs, the usage of it, and the development of the interface between package “ type and ” on behalf of the database. Sharing is because of this reuse. The advantage of the yesteryear from a practical point of position, the terminal user more willing to allow little “ leap ” related to object relation, but from, must cover with a wholly different paradigm ( object-oriented ) .

The Main Characteristics and the Advantages of Object Oriented Database

Object-oriented is an understanding method, is besides a new scheduling method. Object oriented method and database engineerings together, do the database system analysis, design, maximal bound conform to the nonsubjective apprehension of the universe. Object-oriented database system is a database system in order to run into the new database applications need a new coevals. The advantages of the object-oriented database of flexibleness and simple to build a database: position from package development chance, the user interface between and relational database scheduling is flexible and friendly. At present in most merchandises RDDMS use standard question linguistic communication of SQL, and let users to entree information from a merchandise about no difference, another merchandise. Interface and relational database application package have a similar plan entree mechanism, and supply a big figure of standard informations entree methods. Database design and standardisation procedure is simple, easy to understand. Strong relational database, a broad scope of maps, has efficaciously support many database applications feel satisfied.In the object refers to the particular operation bag in a set of properties and group properties. Inheritance of category a basic dealingss in a category hierarchy of different sort of associated Shared belongingss and runing mechanism. News is a agency of communicating between objects, an object sending messages to another object petition it service. In add-on, object-oriented informations characteristic bag information concealing message polymorphism

Decision of Question2

In the decision, relational database of three sorts of categorization, object-oriented database and object relation database has its ain features and practical. Because they give database many subsidiary. So we have to utilize.

8.0 Appendix

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