Re: Problem with oids for table names getting out of sync?

One other thing about this issue.  A work around is that I can parse sql
statements myself to come up with the table names.  Yes, it's a bit of
work, but not too bad.  My question is whether or not column/table
combinations are guaranteed to return in the order that the table names
appear in a query.  It seems like they're always returned this way.  For
instance:

select * from projects join employees on projects.manager = employees.id;

projects.id would always appear in the return list before employees.id?



Omar Eljumaily wrote:
> This is with 8.1.8, but I don't see any mention of any bug fixes that
> cover this.
>
> I've run into this sort of obscure problem.  I'm using libpq with a
> front end database api where I need to track column names and how
> they're returned in libpq queries.  What's happening is that I start
> out with a set of table names when I open my database with a query:
>
> SELECT relfilenode, relname FROM pg_class WHERE relname !~
> '^(pg_|sql_)' AND relkind = 'r'
>
> But these don't agree with the oids when I subsequently fetch my rows
> and use the following:
>
>            Oid o = PQftable(_res, i);
>            std::string s1 = _con->_oidTableNames[o];
>
> _con->_oidTableNames is my own array that I've created with the above
> select query.  The reason I need to get table names after queries is
> that queries often return with multiple cases of a single column name,
> but with different table names.  I need to be able to decifer the
> table.column combination when people refer to a column in that way.
>
> My problem is that the Oids returned by PQftable sometimes do not
> return from the select query.  For instance
>
> Oid returned from PQftable = 654989
> select relname from FROM pg_class WHERE relfilenode = 654989
> returns empty.
>
> The way I can solve this problem is by dumping and restoring the
> database.  That's the only way I can fix it.
>
> I don't know how to reproduce the problem.  Has anybody heard of
> this?  I'm going to update to the latest version this weekened.  Maybe
> that will fix it.
> Is there any other way to get table names from libpq queries without
> using the oid method I use above?
>
> One other thing I just remembered.  The next time it happens I'm going
> to try a postgresql java driver with similar queries to see if the
> table.column combinations in ResultSet.getString() get messed up as
> well.  That will tell me something.  I suppose I can look and see how
> they get tablename information.
>
> Thanks
>
>
>
>
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