Perl Dbi Die On Error
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 and the cause for error is obvious. 4.5.1. Automatic Versus Manual Error Checking Early versions of the DBI required programmers to perform their own error checking, in a traditional way similar to the examples 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 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 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 t
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 http://docstore.mik.ua/orelly/linux/dbi/ch04_05.htm 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; } http://stackoverflow.com/questions/6649456/error-handling-on-dbi-connect 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("select * from doesntexist"); That said, you should be logging errors, and for a web application, the web server's logs makes sens
Q&A Tutorials Poetry RecentThreads NewestNodes Donate What'sNew on Jun 23, 2003 at 14:47UTC ( #268189=perlquestion: print w/replies, xml ) Need Help?? Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question: Help ?!?!?Using DBI I call a PL/SQL package and hand http://www.perlmonks.org/?node_id=268189 it some variables. This package does some validation of the data, when the package is not happy with the data an SQL error is raised.What I want to do is instead of having DBI die, I want to https://www.safaribooksonline.com/library/view/programming-the-perl/1565926994/ch04s05.html see the error in a variable so I can process this and send back an error to the user.The variables are handed in via a webpage and errors should be returned on that page (thus the dislike perl dbi of a die)I have seen some solutions to this, but these usualy use a eval{} to solve the problem. Due to the application framework that I'm forced to work in this will not work as a die is always caught before my code can get to it.So what I wat is a way to find the errors returned without death.The ways I have atempted to get these errors from the DBI are: - my perl dbi die $error = $dbh->errstr; - my $error = $@The problem is that both are always undefined no matter how may errors the package returns. So my question is how do I find the errors without having the DBI calling dieThis is my config: - Perl v5.6.1 built for sun4-solaris - DBI DBI version 1.34 - Oracle DBD complited with Oracle 8.1.7 clientComment on DBI - PL/SQL error catchingSelect or Download Code Replies are listed 'Best First'. Re: DBI - PL/SQL error catching by gmax (Abbot) on Jun 23, 2003 at 15:15UTC If eval id not a viable solution, then you have to check every DBI call, but only after you instruct the DBI not to do anything in case of errors. #!/usr/bin/perl -w use strict; use DBI; # # ---- untested # my ($dns, $user, $password) = ("dbi:wathever:db","me","secret"); my $dbh = DBI->connect($dns,$user,$password, {RaiseError=>0 , PrintError=>0}) # <-- be quiet! or die "can't connect ($DBI::errstr)\n"; my $sth= $dbh->prepare("SELECT WRONG FROM NON_EXISTING"); if ($sth) { # fetch your records while (my $rec = $sth->fetchrow_arrayref()) { print "@$rec\n"; } } else { print "something was wrong: ", $dbh->errstr, "\n"; # deal with the problem here } [download] Notice that you can't use $dbh->errstr after a failed connection, because the result would be an undefined $dbh. Be also aware that, using this approach, you are entirely respons
Published by O'Reilly Media, Inc. Programming the Perl DBI SPECIAL OFFER: Upgrade this ebook with O’Reilly A Note Regarding Supplemental Files Preface Resources Typographical Conventions How to Contact Us Code Examples Acknowledgments 1. Introduction From Mainframes to Workstations Perl DBI in the Real World A Historical Interlude andStanding Stones 2. Basic Non-DBI Databases Storage Managers and Layers Query Languages and Data Functions Standing Stones and the Sample Database Flat-File Databases Putting Complex Data into Flat Files Concurrent Database Access and Locking DBM Files and the BerkeleyDatabase Manager The MLDBM Module Summary 3. SQL and Relational Databases The Relational Database Methodology Datatypes and NULL Values Querying Data Modifying Data Within Tables Creating and Destroying Tables 4. Programming with the DBI DBI Architecture Handles Data Source Names Connection and Disconnection Error Handling Utility Methods and Functions 5. Interacting with the Database Issuing Simple Queries Executing Non-SELECT Statements Binding Parameters to Statements Binding Output Columns do( ) Versus prepare( ) Atomic and Batch Fetching 6. Advanced DBI Handle Attributes and Metadata Handling LONG/LOB Data Transactions, Locking, and Isolation 7. ODBC and the DBI ODBC—Embraced and Extended DBI—Thrashed and Mutated The Nuts and Bolts of ODBC ODBC from Perl The Marriage of DBI and ODBC Questions and Choices Moving Between Win32::ODBC and the DBI And What About ADO? 8. DBI Shell and Database Proxying dbish—The DBI Shell Database Proxying A. DBI Specification Synopsis Description The DBI Class Methods Common to All Handles Attributes Common to All Handles DBI Database Handle Objects DBI Statement Handle Objects Further Information See Also Authors Copyright Acknowledgments Transla