3. Statements : OpenROAD SQL Statements : Create View Statement : Create View Description
 
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Create View Description
The create view statement uses a select statement to define the contents of a virtual table. The view definition is stored in the system catalogs. When the view is used in a statement, the statement operates on the underlying tables. When a table or view used in the definition of a view is dropped, the view is also dropped.
Data can be selected from a view the same way data is selected from a base table. However, updates, inserts, and deletes on views are subject to several restrictions. Updates, inserts, and deletes are allowed only if the view meets all the following conditions:
The view is based on a single updatable table or view.
All columns see columns in the base table or view (no aggregate functions or derived columns are allowed).
The select statement omits distinct, group by, union, and having clauses.
Inserts are not allowed if a mandatory (not null not default) column in a base table is omitted from the view.
A maximum of 1024 columns can be specified for a view.
Note:  This statement has additional considerations when used in a distributed environment. For more information, see the Ingres Star User Guide.