I'm trying to create a new row using DBIx::Class from within Catalyst, with the following code:
$c->model('Session')->resultset('UserPreference')->create(
{
appname => 'rss_reader',
username => $username,
data => $data,
},
);
But, I hit this error every time:
Caught exception in App::Controller::rss->dbo "Can't call method "resolve" on an undefined value at /etg/source/Linux/pkg/perl-5.8.8/lib/site_perl/5.8.8/DBIx/Class/Row.pm line 1309."
I see a few mailing lists talking about this error being thrown as an incorrect blanket error when the query fails for whatever reason (perms, constraints,etc.), but it looks just fine AND even running with DBIC_TRACE=1, I don't even see the generated query in my console.
I should mention I don't think there's something bad with the permissions,etc. since using the database handle manually works:
my $stm=$c->model("Session")->storage->dbh->prepare("insert into user_preferences (username,appname,data) values ('mphillip','rss_reader','cookies')"); $stm->execute();
Have you tried update_or_create instead of create? If a row exists create will fail.
Related
I have inherited some old code. It gets a list of categories from a MySQL database table. I'm tasked with adding multilevel support to them. I've almost got it done, but for some reason it just errors out when I go to try the app in action.
The error is (you can also see it at http://detyams.ru/?cat=1):
Can't use an undefined value as an ARRAY reference at /usr/local/lib/perl5/site_perl/mach/5.18/DBI.pm line 2074, line 2231.
sub catlist
{
my $self=shift;
state $sth=$self->db->prepare(q/SELECT c.cat_id,c.cat_name,COUNT(pn.p_id) as cnt from category c
LEFT JOIN price_new pn ON (pn.cat_id=c.cat_id) GROUP BY pn.cat_id WHERE c.parent_id=?/);
$sth->execute(0);
my #catlist=$sth->fetchall_arrayref({}); # <- this call leads to the failure in the deep of DBI code.
foreach my $item (#catlist)
{
$sth->execute($item->{cat_id});
$item->{children}=$sth->fetchall_arrayref({});
}
return #catlist;
}
I've looked up some examples of using the DBI methods in there (like http://www.perlmonks.org/?node_id=284436#loh), all appear to be in accord with my code.
Oh, so, it just turned out if in case of a query syntax error (WHERE clause was placed in wrong position) fetchall_arrayref() appears to report cryptic errors instead of the underlying problem. Found out by checking server logs.
I'm checking with MongoDB application. There is application installed on my system, when I enter single quote(') in the input box it pop up the following error:
A problem occurred in a Python script. Here is the sequence of function calls leading up to the error, in the order they occurred.
/usr/lib/cgi-bin/mongo/2.2.3/dbparse.py in ()
41 print "</th>"
42 if where:
=> 43 for record in collection.find(where):
44 print "<tr>"
45 print "<td align=\"center\">"+record["test"]+"</td>"
record undefined, collection = Collection(Database(MongoClient('localhost', 27017), u'test_d'), u'london_garages'), collection.find = <bound method Collection.find of Collection(Data...', 27017), u'test_d'), u'l_g')>, where = {'$where': "this.test== ''--'"}
What is the meaning of the error? If you have another pointer to check the security of this application please let me know.
If you look at the error and the following part:
where = {'$where': "this.test== ''--'"}
I assume the single quote goes to the where clause (some sort of search), so your code is probably something like the following:
where = {'$where': "this.test== '[YOUR TEXT BOX INPUT]--'"}
A single quote terminated your where clause prematurely. This is a good demonstration for a NoSQL injection.
I have a date field inserted in a Lucene database with the following code:
Document.Add(new NumericField("TimeStamp", Field.Store.YES, true).SetLongValue(Data.TimeStamp.ToBinary()));
And I have the following query:
var Sort = new Sort(new SortField("TimeStamp", SortField.LONG, true));
var ParsedQuery = ParseQuery(_Parser, SearchQuery);
var Filter = new QueryWrapperFilter(ParsedQuery);
var Hits = _Searcher.Search(ParsedQuery, Filter, Skip + Limit, Sort);
But it crashes when executing the search method with the following:
A first chance exception of type 'Lucene.Net.QueryParsers.QueryParser.LookaheadSuccess' occurred in Lucene.Net.dll
A first chance exception of type 'System.IO.IOException' occurred in Lucene.Net.dll
A first chance exception of type 'System.IO.IOException' occurred in Lucene.Net.dll
A first chance exception of type 'System.AccessViolationException' occurred in HDIndexing.dll
Additional information: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
If I replace the Sort variable with one of the constants, such as Sort.RELEVANCE then the search works properly.
The problem comes from my custom search.
Incidentally I noticed something else odd and I do not know if these is a connection: If I inspect my Lucene DB with the Luke tool, all my fields are reported to be strings:
http://i.stack.imgur.com/SnlSD.png
I do not know if this is a bug in Luke or something is wrong with how Lucene is set up on my end.
I tried to change the sort to a type 'string' to see what would happen, but it crashes the same way, so either way, the type of the field doesn't seem to have an impact.
Has anyone experienced that problem before?
It could be similar to someone else's post: lucene.net sort not working access violation
i am writing a small perl app using the eXist database, and i am wondering is:
how can i see that my call
my $eXist = XML::eXistDB::RPC->new( destination=>$eXist_db, repository=>$bank, user=>"admin", password=>"pass" ) ;
is successful or not ?
thanx
When object initialisation fails, it will be messaged through Log::Report, so hook into that.
This only happens if the programmer to neglected to set either rpc or destination parameter. The new constructor will always return an object instance.
According to the docs:
All methods return a LIST, where the
first scalar is a return code (RC).
When that code is 0, all went well.
Otherwise, the code represent the
transport error or the exception
(refusal) as reported by the server
logic. In either case, the second
scalar in the returned list contains
the error message. For instance,
Maybe this applies also for the constructor, try:
my ($rc,$eXist) = XML::eXistDB::RPC->new( destination=>$eXist_db, repository=>$bank, user=>"admin", password=>"pass" );
now, if $rc != 0 there was an error.
I'm in a web scripting class, and honestly and unfortunately, it has come second to my networking and design and analysis classes. Because of this I find I encounter problems that may be mundane but can't find the solution to it easily.
I am writing a CGI form that is supposed to work with a MySQL DB. I can insert and delete into the DB just fine. My problem comes when querying the DB.
My code compiles fine and I don't get errors when trying to "display" the info in the DB through the browser but the data and text doesn't in fact display. The code in question is here:
print br, 'test';
my $dbh = DBI->connect("DBI:mysql:austinc4", "*******", "*******", {RaiseError => 1} );
my $usersstatement = "select * from users";
my $projstatment = "select * from projects";
# Get the handle
my $userinfo = $dbh->query($usersstatement);
my $projinfo = $dbh->query($projstatement);
# Fetch rows
while (#userrow = $userinfo->fetchrow()) {
print $userrow[0], br;
}
print 'end';
This code is in an if statement that is surrounded by the print header, start_html, form, /form, end_html. I was just trying to debug and find out what was happening and printed the statements test and end. It prints out test but doesn't print out end. It also doesn't print out the data in my DB, which happens to come before I print out end.
What I believe I am doing is:
Connecting to my DB
Forming a string the contains the command/request to the DB
Getting a handle for my query I perform on the DB
Fetching a row from my handle
Printing the first field in the row I fetched from my table
But I don't see why my data wouldn't print out as well as the end text. I looked in DB and it does in fact contain data in the DB and the table that I am trying to get data from.
This one has got me stumped, so I appreciate any help. Thanks again. =)
Solution:
I was using a that wasn't supported by the modules I was including. This leads me to another question. How can I detect errors like this? My program does in fact compile correctly and the webpage doesn't "break". Aside from me double checking that all the methods I do use are valid, do I just see something like text not being displayed and assume that an error like this occurred?
Upon reading the comments, the reason your program is broken is because query() does not execute an SQL query. Therefore you are probably calling an undefined subroutine unless this is a wrapper you have defined elsewhere.
Here is my original posting of helpful hints, which still apply:
I hope you have use CGI, use DBI, etc... and use CGI::Carp and use strict;
Look in /var/log/apache2/access.log or error.log for the bugs
Realize that the first thing a CGI script prints MUST be a valid header or the web server and browser become unhappy and often nothing else displays.
Because of #3 print the header first BEFORE you do anything, especially before you connect to the database where the script may die or print something else because otherwise the errors or other messages will be emitted before the header.
If you still don't see an error go back to #2.
CGIs that use CGI.pm can be run from a command line in a terminal session without going through the webserver. This is also a good way to debug.