Skeeter87
asked on
1 random dbm record
Im using these lines to retrieve records from my database.. It works
fine but I want to display only 1 RANDOM record at a time, which
ofcourse meets all criteria. To be honoust I dont have a clue how to
display 1 random record at a time..but I'm sure you can help me !?
#!/usr/bin/perl
use CGI;
$q=new CGI;
print "Content-Type: text/html\n\n";
$name = "goods";
die "Missing DBM name.\n" unless $name;
dbmopen(%map,$name,0666);
$rec = 0;
while (($key,$val)=each(%map)) {
($item1,$item2,$item3,$ite
if ($item2 eq "Radio") {
## check $item3 for "philips"
print qq{$item2<br>};
}}
dbmclose(%map);
exit;
fine but I want to display only 1 RANDOM record at a time, which
ofcourse meets all criteria. To be honoust I dont have a clue how to
display 1 random record at a time..but I'm sure you can help me !?
#!/usr/bin/perl
use CGI;
$q=new CGI;
print "Content-Type: text/html\n\n";
$name = "goods";
die "Missing DBM name.\n" unless $name;
dbmopen(%map,$name,0666);
$rec = 0;
while (($key,$val)=each(%map)) {
($item1,$item2,$item3,$ite
if ($item2 eq "Radio") {
## check $item3 for "philips"
print qq{$item2<br>};
}}
dbmclose(%map);
exit;
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ASKER
When I add print @vals; beneath the 'while' line, it prints out the records...
However the split doesnt seem too function ..
Can this method also be used when used with a couple of thousands of records ?
However the split doesnt seem too function ..
Can this method also be used when used with a couple of thousands of records ?
> doesnt print any record
hmm, can't test you example, just the method
probaly this is a better attempt:
while (($key,$val)=each(%map)) { push @vals, rand($.) . "\t" . $val; }
@vals=sort @vals;
($dumm,$item1,$item2,$item
if this fails too, please check if your $item2 contains an expected value
> Can this method also be used when used with a couple of thousands of records ?
it can, but it will be a waste of resources if you just need one of them
I'd use a numeric index in the dbm file and use rand() to select one index randomly, that avoids reading the complete file into memory.
hmm, can't test you example, just the method
probaly this is a better attempt:
while (($key,$val)=each(%map)) { push @vals, rand($.) . "\t" . $val; }
@vals=sort @vals;
($dumm,$item1,$item2,$item
if this fails too, please check if your $item2 contains an expected value
> Can this method also be used when used with a couple of thousands of records ?
it can, but it will be a waste of resources if you just need one of them
I'd use a numeric index in the dbm file and use rand() to select one index randomly, that avoids reading the complete file into memory.
ASKER
I got it too work !! thanks....
Can you give me an example on how to implentate such an numeric index ?
Can you give me an example on how to implentate such an numeric index ?
as you do not use the key in your example, I'd use that as simple integer
then you have to cast the result of rand() to an integer, that's it ..
then you have to cast the result of rand() to an integer, that's it ..
ASKER
ok, thank you very much
ASKER