# Data Modeling - Binary Relation

> (Data|State) Management and Processing > Data Modeling (Relational Database, Code, Graph, Text)

### Table of Contents

## 1 - About

relationship in Binary.

Binary Relation is a relation between two elements.

Binary relations are used in many branches of mathematics to model concepts like:

`is congruent to`

in geometry,`is adjacent to`

in graph theory,`is orthogonal to`

in linear algebra- and many more.

The concept of function is defined as a special kind of binary relation.

## 2 - Articles Related

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## 3 - Example

Example: Suppose there are:

- four objects
`ball, car, doll, gun`

- four persons
`John, Mary, Ian, Venus`

The `owns`

binary relation between the objects and the persons is:

`John`

owns the`ball`

,`Mary`

owns the`doll`

,`Venus`

owns the`car`

,`Nobody`

owns the`gun`

,`Ian`

owns`nothing`

.

This relation may be represented:

R = ( {ball, car, doll, gun}, {John, Mary, Ian, Venus}, { (ball, John), (doll, Mary), (car, Venus) } )

ball | car | doll | gun | |
---|---|---|---|---|

John | + | |||

Mary | + | |||

Ian | ||||

Venus | + |

Two different relations could have the same graph. The graphs of the relations above and below are the same.

R = ( {ball, car, doll, gun}, {John, Mary, Venus}, { (ball, John), (doll, Mary), (car, Venus) } )

ball | car | doll | gun | |
---|---|---|---|---|

John | + | |||

Mary | + | |||

Venus | + |

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