This restriction applies to columns of views that are derived from computed columns or built-in functions. For example, the amt_due column in the view accounts is a computed column.
create view accounts (title_id, advance, amt_due) as select titles.title_id, advance, (price * royalty/100) * total_sales from titles, roysched where price > $15 and advance > $5000 and titles.title_id = roysched.title_id and total_sales between lorange and hirange
The rows visible through accounts are:
select * from accounts
title_id advance amt_due -------- -------- --------- PC1035 7,000.00 32,240.16 PC8888 8,000.00 8,190.00 PS1372 7,000.00 809.63 TC3218 7,000.00 785.63 (4 rows affected)
updates and inserts to the amt_due column are not allowed because there is no way to deduce the underlying values for price, royalty, or year-to-date sales from any value you might enter in the amt_due column. delete operations do not make sense because there is no underlying value to delete.
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