Perl Check Mysql Error
Contents |
Tutorials Poetry RecentThreads NewestNodes Donate What'sNew on Mar 08, 2005 at 15:16UTC ( #437578=perlquestion: print w/replies, xml ) Need Help?? svenXY has asked for the wisdom of the Perl Monks
Perl Dbi Handleerror
concerning the following question: Hi All, In contrary to all perl dbi execute return value documentation I was capable of, I wasn't able to catch a DBI error to replace
Perl Dbi Error Handling Examples
it with another message. I can get the error message into a varialbe, but cannot prevent DBI from displaying the error again. Here's some sample perl dbi connect error handling code: use DBI; my $dbh = DBI->connect("DBI:mysql:database=www;host=myhost.domain.com: +3306;user=auser;password=apwd", {RaiseError => 1, PrintError => 0}); my $sql = 'select wrong_col, correct_col from table limit 10'; my $hash_ref; print "Trying HandleError (with RaiseError on):\n"; $hashref = $dbh->selectall_hashref($sql, 'filename', {RaiseError => 1, PrintError => 1, HandleError => \&handle_error() +}); print "Trying RaiseError perl dbi errstr and eval:\n"; eval{ $hashref = $dbh->selectall_hashref($sql, 'filename', {RaiseError => 1, PrintError => 0}); }; if ($@) { print "\tEval found: $@\n"; } my $sth = $dbh->prepare($sql); print "Trying Errstr:\n"; $sth->execute(); if ($dbh->errstr) { print "\tErrstr: " .$dbh->errstr . "\n"; } sub handle_error { # my $error = shift; print "\tSub 'handle_error': $error\n"; print "\tEnd sub\n"; } [download] As a result, I get: $ perl tester.pl Trying HandleError (with RaiseError on): Sub 'handle_error': End sub DBD::mysql::db selectall_hashref failed: Unknown column 'wrong_col' in + 'field list' at tester.pl line 11. Trying RaiseError and eval: DBD::mysql::db selectall_hashref failed: Unknown column 'wrong_col' in + 'field list' at tester.pl line 16. Trying Errstr: DBD::mysql::st execute failed: Unknown column 'wrong_col' in 'field li +st' at tester.pl line 26. Errstr: Unknown column 'wrong_col' in 'field list' - or - when redirecting STDERR: $ perl tester.pl 2>/dev/null Trying HandleError (with RaiseError on): Sub 'handle_error': End sub Trying RaiseError and
the answer generally runs along the lines of "Why aren't you performing error checking?" Sure enough, nine out of ten times when error checking is added, the exact error message appears
Perl Mysql Dbi
and the cause for error is obvious. 4.5.1. Automatic Versus Manual Error Checking dbi connect perl Early versions of the DBI required programmers to perform their own error checking, in a traditional way similar to the examples
Perl Dbi Connect Oracle
listed earlier for connecting to a database. Each method that returned some sort of status indicator as to its success or failure should have been followed by an error condition checking statement. This is http://www.perlmonks.org/?node_id=437578 an excellent, slightly C-esque way of programming, but it quickly gets to be tiresome, and the temptation to skip the error checking grows. The DBI now has a far more straightforward error-handling capability in the style of exception s. That is, when DBI internally detects that an error has occurred after a DBI method call, it can automatically either warn() or die() with an appropriate message. This shifts the http://docstore.mik.ua/orelly/linux/dbi/ch04_05.htm onus of error checking away from the programmer and onto DBI itself, which does the job in the reliable and tireless way that you'd expect. Manual error checking still has a place in some applications where failures are expected and common. For example, should a database connection attempt fail, your program can detect the error, sleep for five minutes, and automatically re-attempt a connection. With automatic error checking, your program will exit, telling you only that the connection attempt failed. DBI allows mixing and matching of error-checking styles by allowing you to selectively enable and disable automatic error checking on a per-handle basis. 4.5.1.1. Manual error checking Of course, the DBI still allows you to manually error check your programs and the execution of DBI methods. This form of error checking is more akin to classic C and Perl programming, where each important statement is checked to ensure that it has executed successfully, allowing the program to take evasive action upon failure. DBI, by default, performs basic automatic error reporting for you by enabling the PrintError attribute. To disable this feature, simply set the value to 0 either via the handle itself after instantiation, or, in the case of database handles, via the attr
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site http://stackoverflow.com/questions/4822991/perl-dbi-capturing-errors About Us Learn more about Stack Overflow the company Business Learn more about http://stackoverflow.com/questions/6649456/error-handling-on-dbi-connect hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Perl DBI - Capturing errors perl dbi up vote 7 down vote favorite 2 Whats the best way of capturing any DBI errors in Perl. So for example if an insert fails because there were illegal characters in the values being inserted, how can I not have the script fail, but capture the error and handle it appropriately. I don't want to do the "or die" coz I don't want to stop perl dbi connect execution of the script. perl exception error-handling dbi share|improve this question edited Jan 27 '11 at 23:10 Ether 39.8k1065140 asked Jan 27 '11 at 23:02 Chris 65331422 add a comment| 2 Answers 2 active oldest votes up vote 12 down vote accepted Use the RaiseError=>1 configuration in DBI->connect, and wrap your calls to the $dbh and $sth in a try block (TryCatch and Try::Tiny are good implementations for try blocks). See the docs for more information on other connect variables available. for example: use strict; use warnings; use DBI; use Try::Tiny; my $dbh = DBI->connect( $your_dsn_here, $user, $password, { PrintError => 0, PrintWarn => 1, RaiseError => 1, AutoCommit => 1, } ); try { # deliberate typo in query here my $data = $dbh->selectall_arrayref('SOHW TABLES', {}); } catch { warn "got dbi error: $_"; }; share|improve this answer edited Jan 28 '11 at 3:16 cjm 52k795148 answered Jan 27 '11 at 23:03 Ether 39.8k1065140 1 Shouldn't you put the connect within the try block as well? –mscha Jan 27 '11 at 23:13 @mscha: that's not necessary - connect will return undef if it fails. (See the docs - you just nee
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Error handling on DBI->connect up vote 2 down vote favorite 1 Besides handling error using standard code die "Unable to connect: $DBI::errstr\n" is it possible to write a custom code like below? Standard: $dbstore = DBI->connect($dsn, $user, $pw, {ora_session_mode => $mode, PrintError => 0, RaiseError => 0, AutoCommit => 0}) or die "Unable to connect: $DBI::errstr\n"; Custom: $dbstore = DBI->connect($dsn, $user, $pw, {ora_session_mode => $mode, PrintError => 0, RaiseError => 0, AutoCommit => 0}); if (!$dbstore) { CUSTOM_LOG_HANDLER("Could not connect to database: $DBI::errstr"); return; } Sample Standard Code: #!/usr/bin/perl # PERL MODULES WE WILL BE USING use DBI; use DBD::mysql; # HTTP HEADER print "Content-type: text/html \n\n"; # CONFIG VARIABLES $platform = "mysql"; $database = "store"; $host = "localhost"; $port = "3306"; $tablename = "inventory"; $user = "username"; $pw = "password"; #DATA SOURCE NAME $dsn = "dbi:mysql:$database:localhost:3306"; # PERL DBI CONNECT (RENAMED HANDLE) $dbstore = DBI->connect($dsn, $user, $pw) or die "Unable to connect: $DBI::errstr\n"; Thanks for you time. perl dbi share|improve this question asked Jul 11 '11 at 11:30 Hozy 1031210 Are there any other ways to exit gracefully without errors getting logged into the web server logs? –Hozy Jul 11 '11 at 11:37 add a comment| 1 Answer 1 active oldest votes up vote 12 down vote accepted You can always use a custom error handler with the DBI: #!/usr/bin/perl use strict; use warnings; use DBI; sub handle_error { my $message = shift; #write error message wherever you want print "the message is '$message'\n"; exit; #stop the program } my $dbh = DBI->connect( "dbi:SQLite:foo", "user", "pass", { PrintError => 0, HandleError => \&handle_error, } ) or handle_error(DBI->errstr); my $sth = $dbh->prepare("selec