Data retrieval, in database management, involves extracting the wanted data from a database

Database

A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality , in a way that supports processes requiring this information...

. The two primary forms of the retrieved data are reports and queries.

In order to retrieve the desired data the user present a set of criteria by a query. Then the Database Management System

Database management system

A database management system is a software package with computer programs that control the creation, maintenance, and use of a database. It allows organizations to conveniently develop databases for various applications by database administrators and other specialists. A database is an integrated...

 (DBMS), software for managing databases, selects the demanded data from the database. The retrieved data may be stored in a file, printed, or viewed on the screen.

A query language, such as Structured Query Language (SQL

SQL

SQL is a programming language designed for managing data in relational database management systems ....

), is used to prepare the queries. SQL is an American National Standards Institute

American National Standards Institute

The American National Standards Institute is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international...

 (ANSI) standardized query language developed specifically to write database queries. Each DBMS may have its own language, but most relational DBMSs also support SQL.

How the data are presented

Reports and queries are the two primary forms of the retrieved data from a database. There are some overlaps between them, but queries generally select a relatively small portion of the database, while reports show larger amounts of data. Queries also present the data in a standard format and usually display it on the monitor; whereas reports allow formatting of the output however you like and is normally printed.

Reports are designed using a report generator built into the DBMS.

See also

• Database model
  Database model
  A database model is the theoretical foundation of a database and fundamentally determines in which manner data can be stored, organized, and manipulated in a database system. It thereby defines the infrastructure offered by a particular database system...
  
  
• Data maintenance
  Data maintenance
  Data maintenance is the adding, deleting, changing and updating of binary and high-level files, and the real world data associated with those files. Data can be maintained manually and/or through an automated program, but at origination and translation/delivery point must be translated into a...
  
  
• Relational database
  Relational database
  A relational database is a database that conforms to relational model theory. The software used in a relational database is called a relational database management system . Colloquial use of the term "relational database" may refer to the RDBMS software, or the relational database itself...
  
  
• Query by Example
  Query by Example
  Query by Example is a database query language for relational databases. It was devised by Moshé M. Zloof at IBM Research during the mid 1970s, in parallel to the development of SQL. It is the first graphical query language, using visual tables where the user would enter commands, example elements...
  
  

External links

• SQL Statements SQL Statements Tutorial
• SQL Tutorial at W3Schools