loading data into 2d array 1

[inncoggnitto]

i am pulling data from a db and need to push into a 2d array a column at a time. will loop through the following up to three time (so $k will be from 0 to 2). the sql statement will pull one set of data at a time out and there can be up to three recordsets in the results. i need to get the data into the array to put into html table later on. i am getting the following error. "can't use subscript on array slice near q]. the following is what i thought would work. only occasional perl programmer (sorta) so be kind.

thanks

$sth = $dbh->prepare("SELECT * from PSTCOMP WHERE PSTCOMP.FACID = '$requested_fac_id'  AND PSTCOMP.UNIT_ID = '$unit_id' ORDER BY PSTCOMP.TANK_ID, PSTCOMP.COMPART_LETTER");

	$sth->execute();
	while ($fields = $sth->fetchrow_arrayref()) {
		push @comp, [@$fields]; .
		$rowcount_comp++;
	}
#this is where i am trying to read the one dim array into a 2 dim where $k is the column number
	for ($q=0; $q=$#comp; $q++){
		@comp_ary[$k][$q] = $comp[$q];
	}

 

[rosenk]

There are a couple of problems that I can see. The actual error you're getting is because [tt]@comp_ary[$k][$q][/tt] should be [tt]$comp_ary[$k][$q][/tt].

I think that you also need to change:
[tt]push @comp, [@$fields];[/tt]
to:
[tt]push @comp, @$fields;[/tt]

So you're pushing the elements of the array, rather than pushing a reference to an anonymous array containing the elements of the array.

The last problem that I can see, offhand, is that [tt]$q=$#comp[/tt] in the second portion of the [tt]for[/tt] statement should be [tt]$q <= $#comp[/tt]

 

[inncoggnitto]

when i do the first suggestion i gen a new error msg of &quot;type of arg 1 to push must be array(not array element)&quot;

suggestion 2 - the way i have it works (i use it in other scripts) and i got it from the programming perl dbi book on pg 114

i agree with three

just need to get past one still

thanks

 

[justice41]

i am trying to read the one dim array into a 2 dim

@comp is not a 1D array, it's 2D. Each element in the array is a refence to a row array. So $comp[$q] is a reference to the array of the qth row of fields from your DB. This make @comp_ary a 3D array.

If you are going to assign $comp[$q] to $comp_ary[$k][$q] you don't need to loop over $q to do it. You can just do

@{$comp_ary[$k]} = @comp;

jaa

 

[inncoggnitto]

i have tried all suggestions and others from a different source and still all i get out is an array reference in hex.

this is what it looks like (at aleast the last iteration)
+++++++++++++++++++++++++++++++++++++++++++++++++code
#this is the sub to get the data into the array called from the sub below
sub Compartment {
$rowcount_comp = 0;
@comp = ();

$sth = $dbh->prepare(&quot;SELECT * from PSTCOMP WHERE PSTCOMP.FACID = '$requested_fac_id' AND PSTCOMP.UNIT_ID = '$unit_id' ORDER BY PSTCOMP.TANK_ID, PSTCOMP.COMPART_LETTER&quot;
$sth->execute();

while ($fields = $sth->fetchrow_arrayref()) {
push @comp, [@$fields]; #Create copy of array reference. See DBI book pp 113-114.
$rowcount_comp++;
}
for ($q=0; $q<=$#comp; $q++){
# @{$comp_ary->[$k]} = @comp;
$comp_ary->[$k]->[$q] = $comp[$q];
}

#CompDetailsOut($rowcount_comp, \@comp);
$sth->finish;
}

#the first for loop sets the id for the tank and is used in the sql above to get all compartment data, up to 3 comps possible. second loop is supposed to pull data out of array
all i have been able to get out is the reference? ARRAY(0x4025475c), but not the value. i get either the ref or blank regardless of what i try.

#the z output is just for debugging so i can see the counter working. the attachement is a little of the output. pg 273 programming perl3 shows print $AoA[1][2] as the way to specify a specific value for output. the -> thing doesn't change anything in the results good or bad, when i tried it in both subs.

sub CompDetailsOut{
for ($k=0; $k < 3; $k++){
$unit_id = $u_id[$k];
Compartment();
}
$z=0;
for ($k=0; $k < $max_count; $k++){
if (k != 0 ) {
$z++;
}

print qq~
<tr>
<td class=&quot;border2&quot; width=&quot;180&quot;>Compartment Letter:
</td>
<td class=&quot;border2&quot; width=&quot;180&quot;>$comp_ary->[0]->[$z] z=$z
</td>
<td class=&quot;border2&quot; width=&quot;180&quot;>$comp_ary->[1]->[$z] z=$z
</td>
<td width=&quot;180&quot;>$comp_ary->[2]->[$z] z=$z
</td>
</tr>
<tr>
<td class=&quot;border2&quot;>Capacity:
</td>
<td class=&quot;border2&quot;>$comp_ary[$z++][0] z=$z
</td>
<td class=&quot;border2&quot;>$comp_ary[$z][1] z=$z
</td>
<td>$comp_ary[$z][2] z=$z
</td>
</tr>

etc.+++++++++++++++++++++++code end

putting print qq~<h1>$comp[0], $comp[1], $comp[2], $comp[3], $comp[4], $comp[5]</h1>~; into the loop and exiting yeilds
ARRAY(0x4025b468), , , , ,

and if i do a full printout to my output page i get the following for the first sets of data. (looks better in html of course)

Compartments
Compartment Letter: ARRAY(0x4025475c) z=0 ARRAY(0x401a9624) z=0 ARRAY(0x40254184) z=0
Capacity: z=1 z=1 z=1
Substance Stored: z=2 z=2 z=2
Other Substance Stored: z=3 z=3 z=3
Tank Release Detection
I: z=4 z=4 z=4
II: z=5 z=5 z=5
III: z=6 z=6 z=6
Other: z=7 z=7 z=7
Variance:

 

[rosenk]

I still believe that
[tt]while ($fields = $sth->fetchrow_arrayref()) {
push @comp, [@$fields]; #Create copy of array reference. See DBI book pp 113-114.
$rowcount_comp++;
}[/tt]

Should be:
[tt]while ($fields = $sth->fetchrow_arrayref()) {
push @comp, @$fields; #Create copy of array reference. See DBI book pp 113-114.
$rowcount_comp++;
}[/tt]

You're pushing an array reference onto the end of [tt]@comp[/tt], not pushing the values of the columns.

 

[inncoggnitto]

you are correct, i must have missed the dropping the [] part. wonder why it acts differently in this case than in the rest of my script, as this is only a small part of the whole, i have 9 other sql stmts pulling data out.

i thank you.

now all i have to do is to make sure the looping and other stuff i have going on is getting the correct data out.

that is for next week though, time to go home this end.

thanks again