DBI::ODBC fetch and fetchrow

ColtsFoot has asked for the wisdom of the Perl Monks concerning the following question:

I have some code that retrieves 20+ columns from an Oracle
database using DBD::ODBC. The last field is a large memo field.
I've included the line

        $dbh->{LongReadLen} = 1024;
[download]

But when I try to use

        @row = $sth->fetchrow_array();
[download]

I dont get any data back, on the otherhand if I use

        $row = $sth->fetch();
[download]

and then extract the data using

        $memofield = $$row[22];
[download]

things seem to work. Can anyone explain when I should use
fetch and when to use fetchrow_array.

TIA

Comment on DBI::ODBC fetch and fetchrow_array Select or Download Code

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Re: DBI::ODBC fetch and fetchrow_array by BBQ (Curate) on Jul 24, 2000 at 19:25 UTC
I have never heard of just plain fetch, even if I only need a single cell out of the database I will use fetchrow() and its friends. Works for me all the time. Have you tried switching from DBD::ODBC to DBD::Oracle? I have encountered unexpected behavior with DBD::ODBC in the past. Just my R$0.02 worth.. #!/home/bbq/bin/perl # Trust no1!	[reply]
RE: Re: DBI::ODBC fetch and fetchrow_array by DrManhattan (Chaplain) on Jul 24, 2000 at 20:21 UTC
`*fetchrow_arrayref = \&fetch;` [download] fetchrow_arrayref() is fetch() in disguise. -Matt	[reply] [d/l]
(CMonster: bind_columns) RE: DBI::ODBC fetch and fetchrow_array by CMonster (Scribe) on Jul 24, 2000 at 20:21 UTC
As a quick refresher, `fetch` is a synonym for `fetchrow_arrayref`, which in general will be faster than a `fetchrow_array` because it doesn't have to allocate more memory and assign more variables. In ColtsFoot's case, I think variable allocation might be part of the problem if dealing with Memo fields. Try checking the result of `fetchrow_array` for errors; the best way to do that is to turn on `RaiseError` and `PrintError`. You might also want to look at `bind_columns`, which gives the convenience of variables without the pain of re-assigning them for each row.	[reply]
Re: DBI::ODBC fetch and fetchrow_array by agoth (Chaplain) on Jul 24, 2000 at 20:24 UTC
$sth->fetch is an alias for fetchrow_arrayref and $sth->fetchrow is an alias for fetchrow_array HTH	[reply]