You should always use both strict and warnings, as they will catch many common errors. In your example code you used mixed case in your variable names, which would be an easy place to introduce a typo.

After adding strict and warnings you should reduce the code to the simplest form that still behaves incorrectly. Chances are you will find the error by doing this, and if not we will be happy to assist you further. But please confirm that the reduced version still demonstrates the error (and that it runs of course).

Some remarks:

#build a dynamic sql statement
my $Sql_str = &BuildSQLString($cMssFactBag);
print $Sql_str;
#I print here I get no SQL statement
[download]

So far, it looks not too bad, except that you shouldn't be using an ampersand (&) here, unless you know how it alters the behaviour of the subroutine called (circumvents prototypes; without arguments being called, also passes @_ implicitly)

sub BuildSQLString
{
...
$dynam_Sql_stmt = join(" ",$dynam_Sql_stmt, "from $p_str_tblName where
+ RECORDXFEREDTOFILE = 'I'");

#I print here I a SQL statement

return $dynam_Sql_stmt;

}
[download]

Where do $p_str_tblName, $dynam_Sql_stmt come into life? May we see what ... stands for?

A few related hints:

I am turning on strict and will use warnings. I will also remove the & before calling the build sql function. Thank you for the responses.

Incidentally, you don't need to use join if you're just doing a simple concatenation (which it appears you are). One of these varients suffices:

$dynam_Sql_stmt = "$dynam_Sql_stmt from $p_str_tblName where RECORDXFE
+REDTOFILE = 'I'");
# or
$dynam_Sql_stmt = $dynam_Sql_stmt . " from " . $p_str_tblName . " wher
+e RECORDXFEREDTOFILE = 'I'");
[download]

... with my preference toward the former.

But the advice from everyone else is quite good. We need more code, if only we see what the values of some of your variables are, as well as what code you've elided.

You might just have some code that's incorrect case and it can be hard to see that. use strict; will catch those kinds of errors.

s**lil*;  $*=join'',sort split q**;  s;.*;grr; &&s+(.(.)).+$2$1+; $; =
qq-$_-;s,.*,ahc,;$,.=chop for split q,,,reverse;print for($,,$;,$*,$/)
[download]

Well ... there's really not enough code here to make a guess. I would guess there's code somewhere masking your return so .. Use strict warnings and diagnostics or die.

Can you show us what you do get when you print here?  And also what happens when you display it from within the subroutine?

I that if you do something like the following, it should give you more clues ...

use strict;
use warnings;

# ...
#build a dynamic sql statement
my $Sql_str = &BuildSQLString($cMssFactBag);

print "Debug:  Sql_str is:  '$Sql_str'\n";

sub BuildSQLString
{
# ...
$dynam_Sql_stmt = join(" ",$dynam_Sql_stmt,
    "from $p_str_tblName where RECORDXFEREDTOFILE = 'I'");

print "Debug:  in BuildSQLString:  '$dynam_Sql_stmt'\n";

return $dynam_Sql_stmt;
}
[download]