Reference Manual
   CHAPTER 9. SQL Statements     

CREATE VIEW statement

Function 

To create a view on the database. Views are used to give a different perspective on the data, even though it is not stored that way.

Syntax 

CREATE VIEW
... [ owner.]view-name [( column-name, ... )]
... AS select-without-order-by
... [ WITH CHECK OPTION ]

Permissions 

Must have RESOURCE authority and SELECT permission on the tables in the view definition.

Side effects 

Automatic commit.

See also 

DROP statement

CREATE TABLE statement

Description 

The CREATE VIEW statement creates a view with the given name. You can create a view owned by another user by specifying the owner. You must have DBA authority to create a view for another user.

A view name can be used in place of a table name in SELECT, DELETE, UPDATE, and INSERT statements. Views, however, do not physically exist in the database as tables. They are derived each time they are used. The view is derived as the result of the SELECT statement specified in the CREATE VIEW statement. Table names used in a view should be qualified by the user ID of the table owner. Otherwise, a different user ID might not be able to find the table or might get the wrong table.

The columns in the view are given the names specified in the column name list. If the column name list is not specified, the view columns are given names from the select list items. In order to use the names from the select list items, each item must be a simple column name or have an alias-name specified (see SELECT statement).

Views can be updated unless the SELECT statement defining the view contains a GROUP BY clause, an aggregate function, or involves a UNION operation. An update to the view causes the underlying table(s) to be updated.

The WITH CHECK OPTION clause rejects any updates and inserts to the view that do not meet the criteria of the views as defined by its SELECT statement.

The SELECT statement must not have an ORDER BY clause on it. It may have a GROUP BY clause and may be a UNION.

Standards and compatibility 

• SQL/92     Entry level feature.

• Sybase     Supported by Adaptive Server Enterprise.

Examples 

• Create a view showing information for male employees only. This view has the same column names as the base table.

  CREATE VIEW male_employee
  AS SELECT *
  FROM Employee
  WHERE Sex = 'M'

• Create a view showing employees and the departments they belong to.

  CREATE VIEW emp_dept
  AS SELECT emp_lname, emp_fname, dept_name
  FROM Employee JOIN Department
  ON Employee.dept_id = Department.dept_id