Editing Column (database) (section)

{{Short description|Data values in computer science}}
{{more citations needed|date=September 2016}}

In a [[relational database]], a '''column''' is a set of [[data]] values of a particular [[datatype|type]], one value for each [[Row (database)|row]] of a [[table (database)|table]].<ref name="ColumnOther">The term "column" also has equivalent applications in other, more generic contexts. See e.g., [[Flat file database]], [[Table (information)]].</ref> A column may contain text values, numbers, or even pointers to files in the operating system.<ref>{{Cite web|title = Columnar databases in a big data environment|url = http://www.dummies.com/how-to/content/columnar-databases-in-a-big-data-environment.html|website = dummies.com (Big dummies book)|access-date = 2015-11-05}}</ref> Columns typically contain [[Primitive data type|simple types]], though some relational database systems allow columns to contain more complex data types, such as whole documents, images, or even video clips.<ref>{{Cite web|title = What is Database Column? - Definition from Techopedia|url = https://www.techopedia.com/definition/8/database-column|website = Techopedia.com|access-date = 2015-11-05}}</ref>{{better source needed|date=June 2022}} A column can also be called an '''attribute'''.

Each row would provide a data value for each column and would then be understood as a single structured data value. For example, a database that represents company contact information might have the following columns: ID, Company Name, Address Line 1, Address Line 2, City, and Postal Code. More formally, a row is a tuple containing a specific value for each column,<ref>{{Cite news |last=Rosenberg |first=Burton |title=Relational Databases |work=University of Miami |url=https://www.cs.miami.edu/home/burt/learning/Csc598.073/notes/reldb.html |access-date=2021-02-26}}</ref> for example: (1234, 'Big Company Inc.', '123 East Example Street', '456 West Example Drive', 'Big City', 98765).