DERBY-6742(For update statement, collect generated keys if Statement.RETURN_GENERATED_KEYS flag is supplied to the JDBC call.)

This commit now allows JDBC statement to receive a resultset for auto generated keys for an UPDATE statement updating the generated values with DEFAULT clause. Such a resultset will be generated only if the UPDATE statement updated a single row and there were generated columns involved in the update. This functionality already exists for INSERT statement. It is currently implemented for INSERT statement by calling VALUES IDENTITY_VAL_LOCAL() from EmbedStatement.getGeneratedKeys(). I have used this existing mechanism to collect generated values resultset for UPDATE too. This means that the scope of IDENTITY_VAL_LOCAL() function has grown from INSERT statement to also include UPDATE statement. This will require us to update the documentation for IDENTITY_VAL_LOCAL(). I have created DERBY-6753(Docs for IDENTITY_VAL_LOCAL needs to be updated to indicate that the return value will be impacted by single row UPDATE of identity column) for the documentation task.



git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1628596 13f79535-47bb-0310-9956-ffa450edef68