Data retrieval means obtaining data from a database management system (DBMS), like for example an object-oriented database (ODBMS). In this case, it is considered that data is represented in a structured way, and there is no ambiguity in data.

In order to retrieve the desired data the user presents a set of criteria by a query. Then the database management system selects the demanded data from the database. The retrieved data may be stored in a file, printed, or viewed on the screen.

Data retrieval

A query language, like for example Structured Query Language (SQL), is used to prepare the queries. SQL is an American National Standards Institute (ANSI) standardized query language developed specifically to write database queries. Each database management system may have its own language, but most are relational.

Data retrieval

How the data is 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.

Data retrieval

Reports are designed using a report generator built into the database management system.

See also

Database model

Data maintenance

Relational database

Query by Example, a database query language devised in the mid-1970s

References

External links

SQL Statements SQL Statements Tutorial

SQL Tutorial at W3Schools

Database management systems

Relational database management systems