In the context of a
relational database
A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A system used to maintain relational databases is a relational database management system (RDBMS). Many relatio ...
, a row—also called a
tuple—represents a single, implicitly structured
data item in a
table. In simple terms, a database table can be thought of as consisting of ''rows'' and
columns.
"What is a database row?"
Cory Janssen, Techopedia, retrieved 27 June 2014 Each row in a table represents a set of related data, and every row in the table has the same structure.
For example, in a table that represents companies, each row would represent a single company. Columns might represent things like company name, company street address, whether the company is publicly held, its VAT number
A value-added tax identification number or VAT identification number (VATIN) is an identifier used in many countries, including the countries of the European Union, for value-added tax purposes.
In the EU, a VAT identification number can be veri ...
, etc. In a table that represents ''the association'' of employees with departments, each row would associate one employee with one department.
The implicit structure of a row, and the meaning of the data values in a row, requires that the row be understood as providing a succession of data values, one in each column of the table. The row is then interpreted as a relvar composed of a set of tuples, with each tuple consisting of the two items: the name of the relevant column and the value this row provides for that column.
Each column expects a data value of a particular type
Type may refer to:
Science and technology Computing
* Typing, producing text via a keyboard, typewriter, etc.
* Data type, collection of values used for computations.
* File type
* TYPE (DOS command), a command to display contents of a file.
* Ty ...
. For example, one column might require a unique identifier
An identifier is a name that identifies (that is, labels the identity of) either a unique object or a unique ''class'' of objects, where the "object" or class may be an idea, physical countable object (or class thereof), or physical noncountable ...
, another might require text representing a person's name, another might require an integer representing hourly pay in dollars.
See also
* Column (database)
In a relational database, a column is a set of data values of a particular type, one value for each row of the database.The term "column" also has equivalent applications in other, more generic contexts. See e.g., Flat file database, Table (info ...
References
zh-yue:列 (數據庫)
{{DEFAULTSORT:Row (Database)
Data modeling
Relational model