my hash used only once: possible typo

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

hello Monks,
I have a strange warning,
when I try:

my %q= %SQL_Wrapper::q;
[download]

I have:

Name "SQL_Wrapper::q" used only once: possible typo at ...
[download]

But I don't know how avoid this warning.
I know I used %SQL_Wrapper::q and I will never use it again, because It is an assignment by value.

From know I will use %q (not %SQL_Wrapper::q).
How can I avoid that warning message?
Thank you!

Comment on my hash used only once: possible typo Select or Download Code

Replies are listed 'Best First'.
Re: my hash used only once: possible typo by ikegami (Patriarch) on Aug 23, 2010 at 16:40 UTC
I presume you are using `our %q;` [download] in SQL_Wrapper? Change it to `use vars qw( %q );` [download] Of course, you could provide a reasonable interface instead `my %q = SQL_Wrapper->q;` [download]	[reply] [d/l] [select]
Re^2: my hash used only once: possible typo by saintex (Scribe) on Aug 26, 2010 at 12:48 UTC
what is the difference beetween "our" and "use vars"? Thank you for your answer	[reply]
Re^3: my hash used only once: possible typo by Anonymous Monk on Mar 07, 2013 at 17:03 UTC
difference between "our" and "use vars" explained	[reply]
Re: my hash used only once: possible typo by kennethk (Abbot) on Aug 23, 2010 at 16:18 UTC
If you are certain that a warning is spurious, you can disable it locally using `no warnings;`. It is generally considered good form to disable warnings in as small a scope as possible and to only disable the known spurious warning. In this case, the warning is `once` (see Category Hierarchy in perllexwarn), so you could use the code: `no warnings "once"; my %q= %SQL_Wrapper::q; use warnings;` [download] or you could use a do, which is what I usually use in this sort of scenario `my %q= do{ no warnings "once"; %SQL_Wrapper::q; };` [download]	[reply] [d/l] [select]
Re: my hash used only once: possible typo by james2vegas (Chaplain) on Aug 23, 2010 at 16:50 UTC
Are you sure this warning is spurious? Basically it means that `%SQL::Wrapper::q` is not used anywhere else, at all, for example this code doesn't produce the warning: `{ package SQL_Wrapper; use strict; use warnings; our %q; } package main; use strict; use warnings; my %q = %SQL_Wrapper::q; $q{f} = 42;` [download] but this code does: `{ package SQL_Wrapper; use strict; use warnings; # our %q; } package main; use strict; use warnings; my %q = %SQL_Wrapper::q; $q{f} = 42;` [download] What is setting/changing %SQL_Wrapper::q in your program or modules that your program is using?	[reply] [d/l] [select]