db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jørgen Løland <Jorgen.Lol...@Sun.COM>
Subject Re: Updating rows with an open cursor...what is the expected behavior?
Date Wed, 13 Jun 2007 08:56:21 GMT
I discussed this with Bernt just now, and found the following in the 
JDBC 4 spec to be of interest as well:

------8<------
The three different ResultSet types are described below.
1. TYPE_FORWARD_ONLY The result set is not scrollable; its cursor moves 
forward only, from before the first row to after the last row.  

The rows contained in the result set depend on how the underlying 
database materializes the results. That is, it contains the rows that 
satisfy the query at either the time the query is executed or as the 
rows are retrieved.

2. TYPE_SCROLL_INSENSITIVE  The result set is scrollable; its cursor can 
move both forward and backward relative to the current position, and it 
can move to an absolute position.

The result set is insensitive to changes made to the underlying data 
source while it is open. It contains the rows that satisfy the query at 
either the time the query is executed or as the rows are retrieved.

3. TYPE_SCROLL_SENSITIVE  The result set is scrollable; its cursor can 
move both forward and backward relative to the current position, and it 
can move to an absolute position.  

The result set reflects changes made to the underlying data source while 
the result set remains open. The default ResultSet type is 
TYPE_FORWARD_ONLY.
------>8------

It looks like the default behavior (TYPE_FORWARD_ONLY) is more or less 
the same as SQL ASENSITIVE. "That is, it contains the rows that satisfy 
the query ... as the rows are retrieved" should allow different results 
when index and scan are used.

-- 
Jørgen Løland

Mime
View raw message