Codd's Twelve Rules - Rule 6 - View Updating Rule
Rule 6 | View Updating Rule |
Rule | All views that are theoretically updateable are also updateable by the system. |
Description | This rule deals with views, which are virtual tables used to give various users of a database different views of its structure. It’s one of the most challenging rules to implement in practice, and no commercial product fully satisfies it today. A view is theoretically updateable as long as it’s made up of columns that directly correspond to real table columns. |
Example | All views are not updateable. Views can be updateable if they follow the certain rules unlike tables. The following syntax can be used to update views; UPDATE < view_name > SET<column1>=<value1>,<column2>=<value2>,..... WHERE <condition>; |
Some DBMS that fulfills this property |
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