Re: Re: [PATCH] SQLFreeStmt deletes params, but does not reset the stmt->prepared state.

Hi,

I think I'm using the psql-odbc driver hand-patched with
IPD_free_params() commented out, like you said, and it works
fine for us.

Isnt' this already merged into the git repository?
I thought it sounded pretty obvious at the time when I found it,
didn't bother to check afterwards...

greets,
Oliver


Am 24.02.2015 um 16:03 schrieb Faith, Jeremy:
> Hi,
>
> I also found this issue with the PHP odbc extension which uses
> SQL_RESET_PARAMS.
> It causes the following error on the second odbc_execute() call.
>    PHP Warning:  odbc_execute(): SQL error: Unfortunatley couldn't get this
>                  paramater's info, SQL state S1000 in SQLDescribeParameter
>
>
>  >Hi Oliver,
>  >
>  >On 2014/10/17 19:07, Oliver Freyd wrote:
>  >> Hello,
>  >>
>  >> In ResolveOneParam (convert.c:4586) there is code that converts boolean
>  >> '-1' to '1'. This is necessary for MS Access because it uses -1 as true
>  >> representation.
>  >>
>  >> In my application, an Access 2013 frontend with a postgresql backend,
>  >> sometimes this conversion did not work, and the backend would fail like
>  >> this:
>  >>
>  >> invalid input syntax for type boolean: "-1" at character 399
>  >>
>  >> The statement is like this:
>  >>
>  >> DELETE FROM "public"."someview" WHERE "id" = 13020
>  >> AND ... "someboolean" = '-1' ...
>  >>
>  >> This does not happen always, and I've seen it only in DELETE queries,
>  >> when I try to delete a row that has a checkbox that is checked (true).
>  >> The first try always works, the second try (deleting another row) it
> fails.
>  >>
>  >> Now this is how it fails (IMHO):
>  >>
>  >> The ResolveOneParam() function relies on the correct types being
>  >> assigned to the parameters, In qb->ipdopts->parameters there is
>  >> SQLType and PGType. The SQLType is and enum that does not contain
>  >> boolean, only the PGType can be boolean.
>  >>
>  >> In PGAPI_Execute() (execute.c:1025) it calls prepareParameters, where
>  >> the PGTypes are found (don't know how exactly), and put into the stmt,
>  >> as stmt->ipd->ipdf.parameters.
>  >>
>  >> If the PGTypes are not 0, the query runs fine. The second time
>  >> the query is executed, the query is already prepared (stmt->prepared=5)
>  >> and the prepare step is omitted. But then the PGTypes are missing,
>  >> the bool '-1' -> '1' conversion is not done and the query fails.
>  >>
>  >> It turns out Access calls SQLFreeStmt(option=SQL_RESET_PARAMS),
>  >> that does SC_free_params, so the params get deleted.
>  >>
>  >> But the params contain the result of the prepare call,
>  >> so IMHO the stmt->prepared state is now wrong, the transaction is no
>  >> more prepared, so stmt->prepared should be reset to 0.
>  >>
>  >> And that actually fixes the bug.
>  >>
>  >>
>  >> I hope this is useful, it took quite a while to track this down...
>  >
>  >Thank you for your investigation.
>  >
>  >According to the following pages
>  >  http://msdn.microsoft.com/en-us/library/ms709284%28v=vs.85%29.aspx
>  >  http://msdn.microsoft.com/en-us/library/ms710926%28v=vs.85%29.aspx
>  >
>  >, it seems better to reset APD only keeping IPD intact.
>  >
>  >Comments?
>
>
> I tried Oliver's patch and PHP no longer has a problem.
> Inserting 100,000 rows into a simple table takes 47.6s
> No sign of any memory leak.
>
> On the other hand commenting out the IPD_free_params() call also works.
> Same 100,000 inserts take 34.1s, so significantly faster.
> Again no sign of a memory leak. I also tried prepare,execute,free 100K
> times, much slower but again no sign of a memory leak.
>
> I think the SC_Destructor() function will free the IPD params if nothing
> else does. So, unless there is some other path that could cause a leak,
> I would say just commenting out the IPD_free_params() call is a better
> solution.
>
> Regards,
> Jeremy Faith
>
>  >
>  >regards,
>  >Hiroshi Inoue
>  >
>  >> best regards,
>  >>
>  >>      Oliver Freyd
>  >>
>  >> -----------------------------------------------------------------------
>  >> diff --git a/statement.c b/statement.c
>  >> index da5abf5..a019d5d 100644
>  >> --- a/statement.c
>  >> +++ b/statement.c
>  >> @@ -581,6 +581,7 @@ SC_free_params(StatementClass *self, char option)
>  >>       {
>  >>           APD_free_params(SC_get_APDF(self), option);
>  >>           IPD_free_params(SC_get_IPDF(self), option);
>  >> +        if (self->prepared!=NOT_YET_PREPARED)\
>  >> SC_set_prepared(self, NOT_YET_PREPARED);
>  >>       }
>  >>       PDATA_free_params(SC_get_PDTI(self), option);
>  >>       self->data_at_exec = -1;
>  >>
>  >>
>  >>
> Tyco Safety Products/CEM Systems Ltd.
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