In the [[relational model]] of [[database]] management, an object can be a [[Table (database)|table]] or [[Column (database)|column]], or an association between data and a database entity (such as relating a person's age to a specific person).<ref name=Oppel>{{cite book |first=Andy |last=Oppel |title=SQL Demystified |publisher=McGraw Hill |year=2005| page=7 |isbn=0-07-226224-9}}</ref>
==Design patterns==
The following are notable [[software design pattern]]s for OOP objects.<ref name="R.C.Martin">{{cite web |url=http://www.objectmentor.com/resources/articles/Principles_and_Patterns.pdf |title=Design Principles and Design Patterns |last=Martin |first=Robert C. |author-link=Robert Cecil Martin |access-date=28 April 2017 |url-status=dead |archive-url=https://web.archive.org/web/20150906155800/http://www.objectmentor.com/resources/articles/Principles_and_Patterns.pdf |archive-date=September 6, 2015 }}</ref>
*[[Function object]]: with a single method (in C++, the function operator, <code>operator()</code>) it acts much like a function
*[[Immutable object]]: does not change state after creation
*[[First-class object]]: can be used without restriction
*[[Container (data structure)|Container object]]: contains other objects
*[[Factory object]]: creates other objects
*[[Metaobject]]: from which other objects can be created (compare with a [[class (computer science)|class]], which is not necessarily an object)
*[[Prototype pattern|Prototype object]]: a specialized metaobject from which other objects can be created by copying
*[[God object]]: knows or does too much; example of an [[anti-pattern]]
*[[Singleton pattern|Singleton object]]: only instance of its class for the lifetime of the program
*[[Filter object]]: receives a stream of data as its input and transforms it into the object's output
