Column (database)

In a relational database, a column is a set of data values of a particular type, one value for each row of a table.[1] A column may contain text values, numbers, or even pointers to files in the operating system.[2] Columns typically contain simple types, though some relational database systems allow columns to contain more complex data types, such as whole documents, images, or even video clips.[3][better source needed] 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,[4] for example: (1234, 'Big Company Inc.', '123 East Example Street', '456 West Example Drive', 'Big City', 98765).

  1. ^ The term "column" also has equivalent applications in other, more generic contexts. See e.g., Flat file database, Table (information).
  2. ^ "Columnar databases in a big data environment". dummies.com (Big dummies book). Retrieved 2015-11-05.
  3. ^ "What is Database Column? - Definition from Techopedia". Techopedia.com. Retrieved 2015-11-05.
  4. ^ Rosenberg, Burton. "Relational Databases". University of Miami. Retrieved 2021-02-26.