Re: Issue with prepared statement

On Jun 5, 6:52 pm, [email protected] (listmail) wrote:
> Lethal Possum wrote:
> > Hello,
>
> > I am trying to create a prepared statement for the following query in
> > MySQL:
>
> > INSERT IGNORE INTO foo (group, value) (SELECT 101, value FROM bar
> > WHERE value LIKE '%something%');
>
> > So far my Perl code looks something like this:
>
> > my $group = 101;
> > my $pattern = '%something%';
> > my $query = 'INSERT IGNORE INTO foo (group, value) (SELECT ?, value
> > FROM bar WHERE value LIKE ?);';
> > my $sth = $dbh->prepare($query);
> > $sth->execute($id, $pattern) or die($sth->errstr);
>
> > It does not insert anything into the table foo even though there are
> > values in table bar that match the pattern. So my question is: what am
> > I doing wrong. I have other, simpler prepared queries in my program
> > that work just fine but this one does not do anything and does not
> > trigger any error as far as I can see.
>
> > Are ? parameters allowed in a nested SELECT?
> > Are they allowed not in the WHERE clause?
> > Are they allowed with the LIKE operator?
>
> > Thanks in advance for your help.
>
> > Tom
>
> I haven't ever tried binding column names so I am not sure about that
> piece.  I don't have access to a db at the moment but for the LIKE
> portion maybe try something such as this output indicates.  I believe it
> is what I've done in the past.  It implies excluding % in $pattern and
> moving it to the select statement.
>
> perl -e "print q{INSERT IGNORE INTO foo (group, value) (SELECT ?, value
> FROM bar WHERE value LIKE '%'||?||'%'};"

Hi again,

OK this is embarrassing: I found the bug that prevented my query to be
executed at all. I am very sorry for waisting your time. If it is any
consolation, I learn quite a bit from reading the DBI doc over and
over again.

Thanks you very much for your help and enjoy the rest of your week-
end,

Tom