Re: JDBC and positioned updates

Hi,

We cannot use the updatable result set technique since we support
multiple databases so we want to use the AINSI syntax with the CURRENT
OF cursor_name.

We tried to implement the java.sql.Statement#*setCursorName*(String) and
the java.sql.ResultSet#*getCursorName*() methods so that we can set the
cursor name of an SQL statement. But, it seems to be more complicated
than that we expected since the database server always says *"cursor
"name" does not exist**"

*What we did is to change a little bit the implementation of the
*org.postgresql.core.v3.QueryExecutorImpl *in a way that we can define a
cursor name for an SQL statement. We tried to inject this in the
*org.postgresql.core.v3.Portal *class but we did not succeed.

Any ideas ?

Best regards

On 12/25/2015 04:38 PM, Vladimir Sitnikov wrote:
> 1) Have you considered using "updatable ResultSet"?
>
> Here's a sample:
> https://github.com/pgjdbc/pgjdbc/blob/32f513370306529005cb36d968f8e415f4a88aec/pgjdbc/src/test/java/org/postgresql/test/jdbc2/UpdateableResultTest.java#L301-L303
>
> 2) > WHERE CURRENT OF cursor_name
>
> ResultSet implementation fetches result rows in batches, thus "current
> of" at the database side might point to a slightly different row than
> ResultSet at the java side.
>
> 3) You do not expect high throughput of that kind of API, do you?
> Updatable ResultSet is not using batching, so each update would result
> in a database roundtrip.
>
> Vladimir