This article needs additional citations for verification. (September 2016) |
In a relational database, a column is a set of data values of a particular type, one value for each row of a table. A column may contain text values, numbers, or even pointers to files in the operating system. 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.[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, for example: (1234, 'Big Company Inc.', '123 East Example Street', '456 West Example Drive', 'Big City', 98765).
Field
The word 'field' is normally used interchangeably with 'column'. However, database perfectionists tend to favor using 'field' to signify a specific cell of a given row. [citation needed] This is to enable accuracy in communicating with other developers. Columns (really column names) being referred to as field names (common for each row/record in the table). Then a field refers to a single storage location in a specific record (like a cell) to store one value (the field value). The terms record and field come from the more practical field of database usage and traditional DBMS system usage (This was linked into business like terms used in manual databases e.g. filing cabinet storage with records for each customer). The terms row and column come from the more theoretical study of relational theory.
Another distinction between the terms 'column' and 'field' is that the term 'column' does not apply to certain databases, for instance key-value stores, that do not conform to the traditional relational database structure.
See also
- Column-oriented DBMS, optimization for column-centric queries
- Column (data store), a similar object used in distributed data stores
- Row (database)
- SQL
- Query language
- Column groups and row groups
References
- The term "column" also has equivalent applications in other, more generic contexts. See e.g., Flat file database, Table (information).
- "Columnar databases in a big data environment". dummies.com (Big dummies book). Retrieved 2015-11-05.
- "What is Database Column? - Definition from Techopedia". Techopedia.com. Retrieved 2015-11-05.
- Rosenberg, Burton. "Relational Databases". University of Miami. Retrieved 2021-02-26.
- "An introduction to databases". www.ucl.ac.uk. Retrieved 2015-11-05.
- Drake, Mark (August 9, 2019). "A Comparison of NoSQL Database Management Systems and Models". Digital Ocean. Retrieved 2021-02-26.
This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Column database news newspapers books scholar JSTOR September 2016 Learn how and when to remove this message In a relational database a column is a set of data values of a particular type one value for each row of a table A column may contain text values numbers or even pointers to files in the operating system 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 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 for example 1234 Big Company Inc 123 East Example Street 456 West Example Drive Big City 98765 FieldThe word field is normally used interchangeably with column However database perfectionists tend to favor using field to signify a specific cell of a given row citation needed This is to enable accuracy in communicating with other developers Columns really column names being referred to as field names common for each row record in the table Then a field refers to a single storage location in a specific record like a cell to store one value the field value The terms record and field come from the more practical field of database usage and traditional DBMS system usage This was linked into business like terms used in manual databases e g filing cabinet storage with records for each customer The terms row and column come from the more theoretical study of relational theory Another distinction between the terms column and field is that the term column does not apply to certain databases for instance key value stores that do not conform to the traditional relational database structure See alsoColumn oriented DBMS optimization for column centric queries Column data store a similar object used in distributed data stores Row database SQL Query language Column groups and row groupsReferencesThe term column also has equivalent applications in other more generic contexts See e g Flat file database Table information Columnar databases in a big data environment dummies com Big dummies book Retrieved 2015 11 05 What is Database Column Definition from Techopedia Techopedia com Retrieved 2015 11 05 Rosenberg Burton Relational Databases University of Miami Retrieved 2021 02 26 An introduction to databases www ucl ac uk Retrieved 2015 11 05 Drake Mark August 9 2019 A Comparison of NoSQL Database Management Systems and Models Digital Ocean Retrieved 2021 02 26
