About the SELECT List of an Updatable View

In a CREATE VIEW statement, the SELECT column_list for an updatable view must follow these rules:

  • The SELECT column_list can contain only single field references. In other words, all columns in the SELECT list must also be columns in the table referenced in the FROM clause. A view with one or more derived columns is not updatable. A derived column is a column that is generated based on an expression, for example: column1+5, column1||column2.

  • The SELECT column_list cannot be a subquery.

  • The SELECT column_list cannot contain an aggregate function, for example: SUM, MIN, MAX, COUNT (see SQL Aggregate Functions).

  • The SELECT column_list cannot contain the DISTINCT keyword because doing so would make it possible to not update any row in the underlying table as well as to not update all rows of the underlying table.