[jira] [Updated] (CALCITE-5443) Reset update count when checking for more results

["Julian Hyde (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/CALCITE-5443?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Julian Hyde updated CALCITE-5443:
---------------------------------
    Fix Version/s: avatica-1.23.0

> Reset update count when checking for more results
> -------------------------------------------------
>
>                 Key: CALCITE-5443
>                 URL: https://issues.apache.org/jira/browse/CALCITE-5443
>             Project: Calcite
>          Issue Type: Bug
>          Components: avatica
>            Reporter: Gregory Hart
>            Assignee: Gregory Hart
>            Priority: Major
>             Fix For: avatica-1.23.0
>
>          Time Spent: 10m
>  Remaining Estimate: 0h
>
> After {{java.sql.Statement.getMoreResults()}} has returned false, {{Statement.getUpdateCount()}} should return {{{}-1{}}}. This indicates to the client that there are no additional result sets available. Calcite currently supports at most one result set per SQL statement.
> *Background*
> Some databases, such as Oracle Database, allow stored procedures to return multiple result sets. The JDBC API provides {{Statement.getMoreResults()}} for users to check if the statement has more than one result set and to retrieve the next result set. Calcite does not support this feature and only returns zero or one result set. The problem is that Calcite sometimes returns the wrong value for {{Statement.getUpdateCount()}} and indicates that additional results are available.
> The JavaDoc for {{java.sql.Statement#getMoreResults(int)}} says there are no more results when the following is true:
> {code:java}
> // stmt is a Statement object
> ((stmt.getMoreResults(current) == false) && (stmt.getUpdateCount() == -1)) {code}
> In {{{}AvaticaStatement{}}}, {{getMoreResults(int)}} always returns {{false}} to indicate there are no more {{ResultSet}} objects, but does not reset the {{updateCount}} which can indicate that there was an additional result (but that's not true). Since the JavaDoc states that clients should call both {{getMoreResults}} and {{getUpdateCount}} to determine if there are more results, any client that has the above Java code in a while loop would never reach an exit condition resulting in an infinite loop.
> *Steps to reproduce:*
>  # Execute an INSERT query by calling Statement#execute(String). Verify that the return value is false indicating it is an update count.
>  # Call Statement#getMoreResults(). Verify that the return value is false indicating it is an update count or there are no more results.
>  # Call Statement#getUpdateCount().
> *Expected results:*
> The call to getUpdateCount() returns -1 indicating there are no more results.
> *Actual results:*
> The call to getUpdateCount() returns the update count for the INSERT query, which should only have one result.



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