View (SQL): Difference between revisions

Revision as of 17:40, 14 December 2017

Revision as of 17:42, 14 December 2017

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In a [[database]], a '‘''view''’ is the [[result set]] of a ''stored'' [[Query language|query]] on the [[data]], which the [[database]] users can query just as they would in a persistent database collection object. This pre-established query command is kept in the database dictionary. Unlike ordinary ''base tables'' in a [[relational database]], a view does not form part of the [[database design|physical schema]]: as a result set, it is a virtual tables computed or collated dynamically from data in the database when access to that view is requested. Changes applied to the data in a relevant ''underlying table'' are reflected in the data shown in subsequent invocations of the view. In some [[NoSQL]] databases, views are the only way to query data.

Views can provide advantages over tables: