Lilly Schoen: Created page with "{{GlossaryTermTemp |Abbreviation=PK |SubtermOf=Database table |Definition=1. A primary key is a field in a table that contains unique data. 2. A Primary Key ist a non-empty s..."

2017-11-02T12:42:02Z

Created page with "{{GlossaryTermTemp |Abbreviation=PK |SubtermOf=Database table |Definition=1. A primary key is a field in a table that contains unique data. 2. A Primary Key ist a non-empty s..."

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{{GlossaryTermTemp
|Abbreviation=PK
|SubtermOf=Database table
|Definition=1. A primary key is a field in a table that contains unique data.
2. A Primary Key ist a non-empty set of columns that contain non-null values and whose values uniquely identify a row. A table cannot have more than one PrimaryKey. Often the term PrimaryKey is used to refer to a set of columns which is a strict subset of all of the columns in the table. In many cases it is assumed that the PrimaryKey consists of a single column.
|Sources=https://en.wikibooks.org/wiki/A-level_Computing/AQA/Problem_Solving,_Programming,_Operating_Systems,_Databases_and_Networking/Databases/Primary_keys (1.); http://wiki.c2.com/?PrimaryKey (2.)
}}
Author: Laura Saupe

Primary Key - Revision history

Lilly Schoen: Created page with "{{GlossaryTermTemp |Abbreviation=PK |SubtermOf=Database table |Definition=1. A primary key is a field in a table that contains unique data. 2. A Primary Key ist a non-empty s..."