DATABASE

• Database


  • Organized data for access and manipulation under pragmatic or application control
  • Collection of data or information that is organized so that it can easily be accessed, managed, and updated
• Data entry


  A piece of data in a database
• Field


  A category under which data entries are categorized, where all data entries under a field are of the same datatype
• Record


  A row of adjacent data entries under different fields
• Types of Databases


  • Flat File Database
  • Relational Database
• Flat File Database


  • Consist of a single large table which contain all data entries
• Relational Database


  • A system designed by Edgar Codd of IBM in 1970 and consists of several logically related tables
• Primary Key (PK)


  Fields containing values that uniquely identify each record in a table
• Foreign Key (FK)


  Fields which establishes and enforces a link between the data in two tables to control the data that can be stored in the foreign key table
• Structured Query Language (SQL)


  Standard computer language (by ANSI and ISO) that creates and manages relational databases
• Open Database Connectivity (ODBC)

  An "adaptor" Microsoft and Oracle applications used to communicate to SQL-based databases
• Object-link and Embedding for Databases (OLE-DB)


  An "adaptor" Microsoft used to communicate its own Component Object Model (COM)-based data sources (not SQL-based, like MS Access) with standardized databases using SQL

  
• Although most database systems use SQL, most DBMS also have their own additional proprietary extensions that are usually only used on their system
• Data binding


  A process used by VB to provide a simple and consistent way for applications, through its user interface, to present and interact with data
• Data Controls


  Controls used to connect and move within databases
• Data Bound Controls


  Specific data controls which display data entries of a database

  
• ADO.NET


  A set of classes which are used by .NET applications to interact with relational databases, XML and other open and proprietary data management systems, both in connected and disconnected access

  
• Main components of ADO.NET for accessing and manipulating data

  • Data Providers
  • DataSet

  
• Data Providers


  "Fetches" data from the database and delivers it to the user interface of the program
• DataSet


  An exact and complete copy of the database as presented to the user interface. It is not the database itself.
• DataTable


  An actual table representation of in-memory data
• DataColumn


  Defines the datatype of the individual data values that appear in the table's records
• DataRow


  An entry for each record of data stored within a table under a specified datatype in a DataColumn
• DataRelation


  Represents a parent/child relationship between two DataTable objects
• DataGrid


  Provides the easiest way to manage a binded data thru a form. It enables display and edit data from SQL database, LINQ query, or any other bindable data source.

  
• A database is always presented as a table of information
• In a database, all information contained in one record are of the different data type
• A primary key is always required in a database