Database

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It is the introduction of the database. For the student of standard VIII.

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Database

  1. 1. DATABASES By Chinmay Kumar Raul
  2. 2. INTRODUCTION <ul><li>Database is a collection of data and information in an organized form. </li></ul><ul><li>Databases are designed to support:- </li></ul><ul><ul><li>Storage </li></ul></ul><ul><ul><li>Retrieval </li></ul></ul><ul><ul><li>Modification and </li></ul></ul><ul><ul><li>Deletion of data </li></ul></ul><ul><li>Database can be stored on:- </li></ul><ul><ul><li>Magnetic tapes </li></ul></ul><ul><ul><li>Magnetic disks </li></ul></ul><ul><ul><li>Optical disks and </li></ul></ul><ul><ul><li>other secondary storage devices. </li></ul></ul>
  3. 3. Organization of Database
  4. 4. FIELDS <ul><li>A FIELD is an item of information consisting of number of characters, bytes or words that are treated together. </li></ul><ul><li>Examples:- </li></ul><ul><ul><li>To form a Name </li></ul></ul><ul><ul><li>To form a Date </li></ul></ul><ul><ul><li>To form a Number </li></ul></ul>
  5. 5. … FIELDS Field Name : A Unique name that defines a field in a database is called a Field Name. Ex.: DOB, emp_name, add, phone, mob etc. Attribute : In relational database, a field is equivalent to a column is called an Attribute.
  6. 6. Data types in Microsoft Access <ul><li>Text </li></ul><ul><li>Use for text or combinations of text and numbers, such as addresses, or for numbers that do not require calculations, such as phone numbers, part numbers, or postal codes. </li></ul><ul><li>Stores up to 255 characters. The FieldSize property controls the maximum number of characters that can be entered. </li></ul>
  7. 7. … Data types in Microsoft Access <ul><li>Memo </li></ul><ul><li>Use for lengthy text and numbers, such as notes or descriptions. </li></ul><ul><li>Stores up to 65,536 characters. </li></ul><ul><li>Number </li></ul><ul><li>Use for data to be included in mathematical calculations, except calculations involving money (use Currency type). </li></ul>
  8. 8. … Data types in Microsoft Access <ul><li>Date/Time </li></ul><ul><li>Use for dates and times. </li></ul><ul><li>Currency </li></ul><ul><li>Use for currency values and to prevent rounding off during calculations. </li></ul><ul><li>AutoNumber </li></ul><ul><li>Use for unique sequential (incrementing by 1) or random numbers that are automatically inserted when a record is added. </li></ul>
  9. 9. … Data types in Microsoft Access <ul><li>Yes/No </li></ul><ul><li>Use for data that can be only one of two possible values, such as Yes/No, True/False, On/Off. Null values are not allowed. </li></ul><ul><li>OLE Object </li></ul><ul><li>Use for OLE objects (such as Microsoft Word documents, Microsoft Excel spreadsheets, pictures, sounds, or other binary data) that were created in other programs using the OLE protocol. </li></ul><ul><li>Stores up to 1 gigabyte (limited by disk space). </li></ul>
  10. 10. … Data types in Microsoft Access <ul><li>Hyperlink </li></ul><ul><li>Use for hyperlinks. A hyperlink can be a UNC path or a URL. </li></ul><ul><li>Stores up to 64,000 characters. </li></ul>
  11. 11. RECORD <ul><li>A collection of related data items, each with their own field type is called a Record . Or row wise data is knows as Record. </li></ul><ul><li>In relational database a record is known as Tuple . </li></ul>
  12. 12. … Record
  13. 13. File <ul><li>A File is a collection of related records, that has a particular name. Or we can say in another way this unique name is called a filename. </li></ul><ul><li>Contents of a file (or a file may store):- </li></ul><ul><ul><li>Data </li></ul></ul><ul><ul><li>Programs </li></ul></ul><ul><ul><li>Documents </li></ul></ul><ul><ul><li>Pictures </li></ul></ul><ul><ul><li>Sound or </li></ul></ul><ul><ul><li>Other information. </li></ul></ul><ul><li>In relational databases, a file is also known as a Table . </li></ul><ul><li>Each record in a table contains a unique field is known as primary key . </li></ul>
  14. 14. QUERY <ul><li>Users retrieve database information using queries. </li></ul><ul><li>A QUERY is a request for information from a database. </li></ul><ul><li>The set of rules for constructing queries is known as a Query Language . </li></ul><ul><li>The Example is : SQL (Structured Query Language) </li></ul>
  15. 15. Database Management System (DBMS) <ul><li>Database Management System is a collection of software programs that provides facilities to store, modify and extract information from a database. </li></ul><ul><li>Database management systems are categorized according to the ‘data model’ they implement. </li></ul><ul><li>Data Models define the methods used inside the database management systems to organize the structure of the databases. </li></ul>
  16. 16. Models of Database <ul><li>Relational databases: </li></ul><ul><ul><li>Most commercial systems are based on this model. </li></ul></ul><ul><li>Object Oriented database: </li></ul><ul><ul><li>This model allows the users to create their own objects and specify how they are related to each other. </li></ul></ul><ul><li>Object Relational databases: </li></ul><ul><ul><li>This model manipulates data in the form of objects providing them with a relational interface. </li></ul></ul><ul><li>Distributed databases: </li></ul><ul><ul><li>This model is used to create databases that are shared by several systems in a network. </li></ul></ul>
  17. 17. … Models of Database <ul><li>Multimedia databases: </li></ul><ul><ul><li>This model produces a database that can store different types of files, that is text, graphics, sound, video etc. </li></ul></ul><ul><li>Network databases: </li></ul><ul><ul><li>This model organizes data in a network by linking the records. </li></ul></ul><ul><li>Hierarchical databases: </li></ul><ul><ul><li>This model organizes data in a hierarchy. </li></ul></ul><ul><li>Flat databases: </li></ul><ul><ul><li>This model stores data in a single file that does not interact with any other data file. </li></ul></ul>

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