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The software that manages a database is called a Database Management System (DBMS). The main purposes of a DBMS are to add, delete, and update the data in the database and to provide various ways to view the data. Popular DBMS software available today is

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Introduction

Table of Contents Question Title Page Number A). Database 1 B). Tables 2 C). Attributes (Columns) 3 D). Tuples (Rows) 4 E). Primary Key 5 F). Composite Primary Key 6 G). Foreign Keys 7 References 8 A). Database A Database is any collection of data organized for storage in a computer memory and designed for easy access by authorized users. The data may be in the form of text, numbers, or encoded graphics. The software that manages a database is called a Database Management System (DBMS). The main purposes of a DBMS are to add, delete, and update the data in the database and to provide various ways to view the data. Popular DBMS software available today is Microsoft Access, Microsoft SQL Server and Oracle. Databases are used in many applications, spanning virtually the entire range of computer software. Databases are the preferred method of storage for large multi-user applications, where coordination between many users is needed. Even individual users find them convenient, and many electronic mail programs and personal organizers are based on standard database technology. ...read more.

Middle

This indicates the type of information that is stored. The user can specify additional properties and other column properties can include whether the column is the table's primary key or whether users must enter a value into it or specify the default value of it. Even after specifying the properties of the column the properties could be edited as wished by the user at anytime. Tables can also have a designated single attribute or a set of attributes that can act as a "key", which can be used to uniquely identify each tuple in the table. For example the columns enumerate (list) values of various attributes the columns of a table. For example in the 'Member' table in the library database enumerates 'Member ID's, 'Member Name's, Addresses, 'Phone Number's, etc... D). Tuples (Rows) A tuple is also known as a record. A tuple contains a complete set of information in a DBMS. In other words it could be said as a section of inter related fields. A record is a set of fields, each field which contains one item of information. ...read more.

Conclusion

There can be two book names with the same title but the authors are different, in this case we have to use a composite primary key to distinguish the incoming books. G). Foreign Keys Foreign keys are established in order to make relations between two specified tables. A foreign key works in conjunction with primary key to make relations among specified tables. For example, you can place a foreign key on the 'Book ID' column in the 'Outdated Books' table to ensure that a value entered in that column matches an existing value in the 'Book ID' column of the Book table. Usually a foreign key is not a primary key; in this case, in the 'Outdated Books' table 'Book ID 'should be a primary key in order to avoid the same 'Book ID' entered twice. In relational database diagrams, a foreign key is automatically placed on specified columns when you create a relationship to a table from another table to which a primary key is attached. The following is a relational database diagram which shows how a foreign key is connected to a primary key. The following picture shows how the values entered in the outdated book table matches the books in Book table. ...read more.

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Here's what a teacher thought of this essay

3 star(s)

***
Generally a good explanations of the main database concepts but a bit confusing in parts

Marked by teacher Ivor Borkin 25/03/2012

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