On 2024-06-17 Mo 5:07 AM, Alvaro Herrera wrote:
On 2024-Jun-16, Andrew Dunstan wrote:+sub query_oneval +{ + my $self = shift; + my $sql = shift; + my $missing_ok = shift; # default is not ok + my $conn = $self->{conn}; + my $result = PQexec($conn, $sql); + my $ok = $result && (PQresultStatus($result) == PGRES_TUPLES_OK); + unless ($ok) + { + PQclear($result) if $result; + return undef; + } + my $ntuples = PQntuples($result); + return undef if ($missing_ok && !$ntuples); + my $nfields = PQnfields($result); + die "$ntuples tuples != 1 or $nfields fields != 1" + if $ntuples != 1 || $nfields != 1; + my $val = PQgetvalue($result, 0, 0); + if ($val eq "") + { + $val = undef if PGgetisnull($result, 0, 0); + } + PQclear($result); + return $val; +}Hmm, here you use PGgetisnull, is that a typo for PQgetisnull? If it is, then I wonder why doesn't this fail in some obvious way? Is this part dead code maybe?
It's not dead, just not exercised ATM. I should maybe include a test scripts for the two new modules.
As you rightly suggest, it's a typo. If it had been called it would have aborted the test.
+# return tuples like psql's -A -t mode. + +sub query_tuples +{ + my $self = shift; + my @results; + foreach my $sql (@_) + { + my $res = $self->query($sql); + # join will render undef as an empty string here + no warnings qw(uninitialized); + my @tuples = map { join('|', @$_); } @{$res->{rows}}; + push(@results, join("\n",@tuples)); + } + return join("\n",@results); +}You made this function join the tuples from multiple queries together, but the output format doesn't show anything for queries that return empty. I think this strategy doesn't cater for the case of comparing results from multiple queries very well, because it might lead to sets of queries that return empty result for different queries reported as identical when they aren't. Maybe add a separator line between the results from each query, when there's more than one? (Perhaps just "join('--\n', @results)" in that last line does the trick?)
psql doesn't do that, and this is designed to mimic psql's behaviour. We could change that of course. I suspect none of the uses expect empty resultsets, so it's probably somewhat moot.
Thanks for looking. cheers andrew -- Andrew Dunstan EDB: https://www.enterprisedb.com
