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

craziness: 

%hash = (
        one => [1,2,3,4,5],
        two => [a,b,c,d,e],
        the => [l,m,n,o,p]
        );

foreach my $key ( keys %hash ) {
        push @cols, $key;
        push @vals, scalar( join ",", @{$hash{$key}} );
}

foreach $val ( @vals ) {
        print "$val";
        print "\n";
}
print "\n";

$statement = 'insert into this (' . (join ",", @cols) . ') values (' .
+ (join ",", @vals) . ')';

print "$statement\n\n";

[download]
prints: 
/home/jptxs > perl sortHashForInsert
l,p
a,b,c,d,e
1,2,3,4,5

[download]
yet change the 'the' hash key's value to anything else and: 
/home/jptxs > perl sortHashForInsert
9,8,7,6,5
a,b,c,d,e
1,2,3,4,5

[download]
craziness!

-- I'm a solipsist, and so is everyone else. (think about it)

Replies are listed 'Best First'.
works now under strict : )
by jptxs (Curate) on Oct 11, 2000 at 08:02 UTC

    got it to work with help from the Chatter crew, but the errors it spit out at first were: 

    Bareword "a" not allowed while "strict subs" in use at sortHashForInse
+rt line 5.
Bareword "b" not allowed while "strict subs" in use at sortHashForInse
+rt line 5.
Bareword "c" not allowed while "strict subs" in use at sortHashForInse
+rt line 5.
Bareword "d" not allowed while "strict subs" in use at sortHashForInse
+rt line 5.
Bareword "e" not allowed while "strict subs" in use at sortHashForInse
+rt line 5.
Bareword "l" not allowed while "strict subs" in use at sortHashForInse
+rt line 6.
Bareword "p" not allowed while "strict subs" in use at sortHashForInse
+rt line 6.

    [download]
    notice it only complains about l and p, the first and last elements of the list on line 6...why??

    because m,n,o, gets interpreted as m/n/o/ the commas get used as alternative quotes for the match operator 'm'
    Perl is too gracious : ) 

    use strict;

my %hash = (
        one => [qw(1 2 3 4 5)],
        two => [qw(a b c d e)],
        the => [qw(l m n o p)]
        );

my (@cols, @vals);

foreach my $key ( keys %hash ) {
        push @cols, $key;
        push @vals, scalar( join ",", @{$hash{$key}} );
}

foreach my $val ( @vals ) {
        print "$val";
        print "\n";
}
print "\n";

my $statement = 'insert into this (' . (join ",", @cols) . ') values (
+' . (join ",", @vals) . ')';

print "$statement\n\n";

    [download]

    -- I'm a solipsist, and so is everyone else. (think about it)

[reply]
[d/l]
[select]
Re: l
by japhy (Canon) on Oct 11, 2000 at 08:40 UTC
    This is the same reason that CGI.pm offers Tr() and TR() in place of tr() for the table row HTML element -- tr is an operator that can't be overloaded. Same with the s HTML tag (for striking through text). And if they ever come out with a y or m tag, they'll have to be called as Y() and M().

    $_="goto+F.print+chop;\n=yhpaj";F1:eval
[reply]
Re: l
by merlyn (Sage) on Oct 11, 2000 at 08:06 UTC
[reply]
Re: l
by Anonymous Monk on Oct 11, 2000 at 19:48 UTC
    These are exactly equivalent: 
    the => [ l,         m,n,o,   p ]
the => ['l', ($_ =~ m/n/o), 'p']

    [download]
    Since the middle term in there, using the match operator, evaluates to undef, that term in the list is ignored entirely, giving you a list reference with two elements: l and p
[reply]
[d/l]
      err.. by "list reference" I meant "array reference".. and by "anonymous monk" I meant "Fastolfe".
[reply]

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