DBIx::Class::Manual::TUserlContributed)DBIx::Class::Manual::Troubleshooting(3)NAMEDBIx::Class::Manual::Troubleshooting - Got a problem? Shoot it.
"Can't locate storage blabla"
You're trying to make a query on a non-connected schema. Make sure you
got the current resultset from $schema->resultset('Artist') on a schema
object you got back from connect().
Tracing SQL
The "DBIC_TRACE" environment variable controls SQL tracing, so to see
what is happening try
export DBIC_TRACE=1
Alternatively use the "storage->debug" class method:-
$schema->storage->debug(1);
To send the output somewhere else set debugfh:-
$schema->storage->debugfh(IO::File->new('/tmp/trace.out', 'w');
Alternatively you can do this with the environment variable, too:-
export DBIC_TRACE="1=/tmp/trace.out"
Can't locate method result_source_instance
For some reason the table class in question didn't load fully, so the
ResultSource object for it hasn't been created. Debug this class in
isolation, then try loading the full schema again.
Can't get last insert ID under Postgres with serial primary keys
Older DBI and DBD::Pg versions do not handle "last_insert_id"
correctly, causing code that uses auto-incrementing primary key columns
to fail with a message such as:
Can't get last insert id at /.../DBIx/Class/Row.pm line 95
In particular the RHEL 4 and FC3 Linux distributions both ship with
combinations of DBI and DBD::Pg modules that do not work correctly.
DBI version 1.50 and DBD::Pg 1.43 are known to work.
Can't locate object method "source_name" via package
There's likely a syntax error in the table class referred to elsewhere
in this error message. In particular make sure that the package
declaration is correct. For example, for a schema " MySchema " you need
to specify a fully qualified namespace: " package MySchema::MyTable; ".
syntax error at or near "<something>" ...
This can happen if you have a relation whose name is a word reserved by
your database, e.g. "user":
package My::Schema::User;
...
__PACKAGE__->table('users');
__PACKAGE__->add_columns(qw/ id name /);
__PACKAGE__->set_primary_key('id');
...
1;
package My::Schema::ACL;
...
__PACKAGE__->table('acl');
__PACKAGE__->add_columns(qw/ user_id /);
__PACKAGE__->belongs_to( 'user' => 'My::Schema::User', 'user_id' );
...
1;
$schema->resultset('ACL')->search(
{},
{
join => [qw/ user /],
'+select' => [ 'user.name' ]
}
);
The SQL generated would resemble something like:
SELECT me.user_id, user.name FROM acl me
JOIN users user ON me.user_id = user.id
If, as is likely, your database treats "user" as a reserved word, you'd
end up with the following errors:
1) syntax error at or near "." - due to "user.name" in the SELECT
clause
2) syntax error at or near "user" - due to "user" in the JOIN clause
The solution is to enable quoting - see
"Setting_quoting_for_the_generated_SQL" in
DBIx::Class::Manual::Cookbook for details.
column "foo DESC" does not exist ...
This can happen if you are still using the obsolete order hack, and
also happen to turn on SQL-quoting.
$rs->search( {}, { order_by => [ 'name DESC' ] } );
Since DBIx::Class >= 0.08100 and SQL::Abstract >= 1.50 the above should
be written as:
$rs->search( {}, { order_by => { -desc => 'name' } } );
For more ways to express order clauses refer to "ORDER_BY_CLAUSES" in
SQL::Abstract
Perl Performance Issues on Red Hat Systems
There is a problem with slow performance of certain DBIx::Class
operations using the system perl on some Fedora and Red Hat Enterprise
Linux system (as well as their derivative distributions such as Centos,
White Box and Scientific Linux).
Distributions affected include Fedora 5 through to Fedora 8 and RHEL5
upto and including RHEL5 Update 2. Fedora 9 (which uses perl 5.10) has
never been affected - this is purely a perl 5.8.8 issue.
As of September 2008 the following packages are known to be fixed and
so free of this performance issue (this means all Fedora and RHEL5
systems with full current updates will not be subject to this
problem):-
Fedora 8 - perl-5.8.8-41.fc8
RHEL5 - perl-5.8.8-15.el5_2.1
This issue is due to perl doing an exhaustive search of blessed objects
under certain circumstances. The problem shows up as performance
degradation exponential to the number of DBIx::Class row objects in
memory, so can be unnoticeable with certain data sets, but with huge
performance impacts on other datasets.
A pair of tests for susceptibility to the issue and performance effects
of the bless/overload problem can be found in the DBIx::Class test
suite, in the "t/99rh_perl_perf_bug.t" file.
Further information on this issue can be found in
<https://bugzilla.redhat.com/show_bug.cgi?id=379791>,
<https://bugzilla.redhat.com/show_bug.cgi?id=460308> and
http://rhn.redhat.com/errata/RHBA-2008-0876.html
<http://rhn.redhat.com/errata/RHBA-2008-0876.html>
Excessive Memory Allocation with TEXT/BLOB/etc. Columns and Large
LongReadLen
It has been observed, using DBD::ODBC, that creating a DBIx::Class::Row
object which includes a column of data type TEXT/BLOB/etc. will
allocate LongReadLen bytes. This allocation does not leak, but if
LongReadLen is large in size, and many such row objects are created,
e.g. as the output of a ResultSet query, the memory footprint of the
Perl interpreter can grow very large.
The solution is to use the smallest practical value for LongReadLen.
perl v5.14.22012-DBIx::Class::Manual::Troubleshooting(3)