$DBI::errstr and Tk:Error

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

Hi, I've posted this also on comp.lang.perl.tk, but am also asking here, because I'm guessing this is more of a Perl problem than Tk.

Anyways, what I need to do is test my sql statement in a prepare statement, and stop executing the Tk callback if an error is raised. The error is plainly raised, but I can't seem to figure out how to have it set a flag, so I can return out of the callback before executing the sql.

$entrysql->bind('<Return>',[sub {
                            $sql = $entrysql->get;
my $sth;
eval {$sth = $dbh->prepare("select $mainstr from info $sql")
                               or warn DBI::errstr $!;
                                        $sth->finish;           };

if ($@){
print "ERROR - $@\n";
print chr(07);
return;
}

.......continue to execute the sql
}
[download]

When I enter a malformed sql statement in the above, I get the following printed to STDOUT. But the $@ is never caught in the eval, and it continues on as if there was no error.

DBD::SQLite::st execute failed: near "=": syntax error at ./ztkdb12a l
+ine 664.
Tk::Error: dbih_setup_fbav: invalid number of fields: 0, NUM_OF_FIELDS
+ attribute probably not set right at ./ztkdb12a line 668.
 <Key-Return>
 (command bound to event)
[download]

I'm not really a human, but I play one on earth. flash japh

Comment on $DBI::errstr and Tk:Error Select or Download Code

Replies are listed 'Best First'.
Re: $DBI::errstr and Tk:Error by jeffa (Bishop) on Mar 11, 2004 at 18:03 UTC
Are you setting `RaiseError` to true when you connect to the database? If you are, try turning it off. Also, you might be able to use `HandleError` to your advantage by having it pass the buck to Tk. jeffa L-LL-L--L-LL-L--L-LL-L-- -R--R-RR-R--R-RR-R--R-RR B--B--B--B--B--B--B--B-- H---H---H---H---H---H--- (the triplet paradiddle with high-hat)	[reply]
Re: $DBI::errstr and Tk:Error by Roy Johnson (Monsignor) on Mar 11, 2004 at 18:22 UTC
Why aren't you `die`-ing in the eval? `warn` doesn't return an error status. The PerlMonk `tr///` Advocate	[reply] [d/l] [select]
Re: $DBI::errstr and Tk:Error by zentara (Cardinal) on Mar 12, 2004 at 01:03 UTC
Ok, I solved my problem. The problem was I erroneously thought I could get a DBI::errstr based on the $sth prepare statement alone....you need an execute too. doh!! So for the benefit of others looking for an answer, here is my code which works fine: `##################################################### $entrysql->bind('<Return>',[sub { $sql = $entrysql->get; eval { local $dbh->{AutoCommit} = 0; my $sth = $dbh->prepare("select $mainstr from info $sql") or die DBI::errstr; $sth->execute or die DBI::errstr; }; if($@){ print chr(07), $@, "bad sql\n"; return} print "seems ok\n"; #....continue on and do it for real` [download] I'm not really a human, but I play one on earth. flash japh	[reply] [d/l]
Re: $DBI::errstr and Tk:Error by zentara (Cardinal) on Mar 11, 2004 at 19:42 UTC
Thanks for those tips, I will check them out and see what effect they have. In the mean time, I hacked together a solution myself.....it seems to work, but only more testing will tell. ;-) `#Set a global my $sqlerror = undef; $entrysql->bind('<Return>',[sub { $sql = $entrysql->get; my $sth; eval {$sth = $dbh->prepare("select $mainstr from info $sql") #or warn DBI::errstr $!; or Tk::Error $!; $sth->finish; }; if($sqlerror){print chr(07);$sqlerror = undef; return;} print "ok\n"; .....continue on ######################################################## sub Tk::Error { (undef,$sqlerror,undef) = @_; print "my error->$sqlerror\n"; }` [download] I'm not really a human, but I play one on earth. flash japh	[reply] [d/l]