Submitted by: @sim1984

when execute sql query

select row_number() over(order by f.rdb$field_name) as rn,
f.rdb$field_name as name
from rdb$fields f
where f.rdb$field_name = '000000'

Error message:
The cursor identified in the UPDATE or DELETE statement is not positioned on a row. no current record for fetch operation.

when execute sql query (non index read)

select row_number() over(order by f.RDB$QUERY_NAME) as rn,
f.RDB$QUERY_NAME as name
from rdb$fields f
where f.RDB$QUERY_NAME = 'ddd'

Result is correct.

RN NAME
-------------------
NULL NULL

Commits: 5424300 FirebirdSQL/fbt-repository@ec4f0c7

====== Test Details ======

Confirmed on 3.0.0.30472:
cursor identified in the UPDATE or DELETE statement is not positioned on a row. no current record for fetch operation