# Boolean operator

A **Boolean operator** ( English Boolean operator ) is a logical operator so an operator which in truth values operated on. It is named after George Boole . The most important application area of the Boolean operators is programming . A mathematical specification of the theory of Boolean operators was formalized in the concept of Boolean algebra . There the Boolean operator acts as a link on a mathematical structure . Symbols are assigned to individual Boolean operators. This is used to clearly display a logic circuit - a combination of networked Boolean operators - and to derive the associated truth table .

Boolean operators are used, for example, in programming. The most common of these operators are the AND (conjunction), OR (disjunction), NOT (negation) and XOR (exclusive *OR* ) operator . Boolean operators are used, for example, in query languages , such as in the SQL expression

SELECT * FROM Customers WHERE Country='Germany'ANDCity='Berlin';

with which all entries are selected from the Customers table that have Germany as the value for the Country column and Berlin as the value of the City column. Such a search procedure is also called a Boolean search procedure .

The NAND and NOR operators are also important operators in digital technology .

## See also

## Individual evidence

- ^ Boolean algebra . In: Ramesh Bangia (Ed.): Dictionary of Information Technology . 2nd Edition. Motilal UK Books of India, 2010, ISBN 978-93-8029815-3 .
- ^ Boolean operator . In: Ramesh Bangia (Ed.): Dictionary of Information Technology . 2nd Edition. Motilal UK Books of India, 2010, ISBN 978-93-8029815-3 .