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

Hey Monks
With regard to this question my current effort is this which is unforunatly still not working. I am sure I am missing something elementrary and would appreciate it if someone could point it out to me.
Thanks 

#!/usr/bin/perl

use strict;

my @views = ( 'view0', 'view1');
my $num_of_views = scalar(@views);
my %hash;
my @global_include = ("size, buffersize, value", "size, buffersize, va
+lue");
my $lastview;
my $output;

for (my $j = 0; $j < $num_of_views; $j++){
   my @array = split (", ",$global_include[$j]);
   pop @array;
   $hash{$j} = \@array;
}

#for (my $j = 0; $j < $num_of_views; $j++){
#   my $ref = $hash{$j};
#   print "HASH CONTAINS FOR $j: ";
#   foreach (@$ref){
#        print "$_\n";
#   }
#}

foreach my $key (sort(keys %hash)){
    # Do this only the first time.
    if(not defined($lastview)){
    $lastview = $key;
    $output = "$key";
    next;
    }

    $output .= " full outer join $key on ";
    my $i;
    my $array_elements_used = scalar(@{ $hash{$key} })-1;
    #loop through all of the elements except for the last
    for($i=0;$i<$array_elements_used;$i++){
    $output .= "$lastview.$hash{$lastview}[$i] = $key.$hash{$key}[$i]"
+;
    # only add an "and" if this is not the last element used.
    $output .= " and " if ($i != ($array_elements_used-1));
    }
    $lastview = $key;
}
print $output, "\n";

[download]

j o h n i r l .

Sum day soon I'Il lern how 2 spelI (nad tYpe)

Replies are listed 'Best First'.
Re: Using hash elements to create an SQL Statemant
by kabel (Chaplain) on Sep 11, 2002 at 09:26 UTC
    i did not work through the logic, but if you replace 
    for (my $j = 0; $j < $num_of_views; $j++){
   my @array = split (", ",$global_include[$j]);
   pop @array;
   $hash{$j} = \@array;
}

    [download]
    with 
    for (my $j = 0; $j < $num_of_views; $j++){
   my @array = split (", ",$global_include[$j]);
   pop @array;
   $hash{$views[$j]} = \@array;
}

    [download]
    it just looks pretty good ;). and if you want to print out a data structure use the package Data::Dumper, that safes you lots of work.
[reply]
[d/l]
[select]
Re: Using hash elements to create an SQL Statemant
by BigD (Scribe) on Sep 11, 2002 at 11:44 UTC
    The new code should look like: 
    use strict;

my @views = ( 'view0', 'view1', 'view3');
my $num_of_views = scalar(@views);
my %hash;
my @global_include = ("buffersize, size, value, speed", "buffersize, s
+ize, value, speed","buffersize, size, value, speed");
my $lastview;
my $output;

for (my $j = 0; $j < $num_of_views; $j++){
   my @array = split (", ",$global_include[$j]);
   pop @array;
   $hash{$views[$j]} = \@array;
}

foreach my $key (sort(keys %hash)){
    # Do this only the first time.
    if(not defined($lastview)){
    $lastview = $key;
    $output = "$key";
    next;
    }

    $output .= " full outer join $key on ";
    my $i;
    my $array_elements_used = @{$hash{$key}}-1;
    #loop through all of the elements, including the last since you ha
+ve removed it in the pop before!!
    for($i=0;$i<=$array_elements_used;$i++){
      $output .= "$lastview.$hash{$lastview}[$i] = $key.$hash{$key}[$i
+]";
      # only add an "and" if this is not the last element used.
      $output .= " and " if ($i != $array_elements_used);
    }
    $lastview = $key;
}
print $output, "\n";

    [download]
    Only notice that the array is different because before you did not want the last element, but know, you remove the last element of the array in the  pop @array, so you do not have to skip the last element. Daniel.
[reply]
[d/l]
[select]

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