Positioned updates and deletes
To perform positioned updates and deletes in a result set, you
use the WHERE CURRENT OF clause with a host variable that contains
an iterator object. For example:
#sql { delete_statement/update_statement
WHERE CURRENT OF :iter };
At runtime, the variable :iter must contain an open iterator object that contains a result set selected from the same table accessed by the query in either delete_statement or update_statement. The current row of that iterator object is deleted or updated.