NAME

When I run the commandline, I see a lot of debugging output

    SV = IV(0x7fb4e24dc858) at 0x7fb4e24dc868
      REFCNT = 1
      FLAGS = (ROK,READONLY)
      RV = 0x7fb4e0b0ddf8
        SV = PVHV(0x7fb4e24c48a0) at 0x7fb4e0b0ddf8
          REFCNT = 1
          FLAGS = (OBJECT,SHAREKEYS)
          STASH = 0x7fb4e2174a80        "DBI::db"
          ARRAY = 0x0
          KEYS = 0
          FILL = 0
          MAX = 7
          RITER = -1

There's some debugging code somewhere in the DBIx::Class::DeploymentHandler dependency chain. We've looked and can't find it :( A case of beer at the next YAPC we meet at to whoever can figure it out.

Although if you see this, there's nothing wrong. The command will work as in the documentation. The only issue is that if there's a lot of debugging scroll by, you might need to page up in your terminal to catch any real error messages.

UPDATE: I recieved an email from a contributor who has code dived a bit and possibly narrowed down the issue. I thought to report that stuff here. When SQLT::Parser::DBIx::Class attempts to serialize schemas that are connected it trys to serialize the connect object information. This doesn't play so nice with the way the YAML serializer works, since it does try hard to serialize objects.

UPDATE: This may be fixed in recent updates to the DBIC ecosystem. If you are seeing this try upgraded DBIC and SQLT and see if it goes away.

UPDATE: You really should not be seeing this anymore, if you are, and you're on the lastest DBIC and related, please let me know.

Contributing

    cpanm Dist::Zilla
    (dzil authordeps; dzil listdeps) |
      (unset AUTHOR_TESTING RELEASE_TESTING; cpanm)

You should first have a Modern Perl setup, including local::lib. If you need help installing Perl and getting started, please take a look at the Learning Perl website: <http://learn.perl.org/installing/>

If Test::Postgresql58 fails to install, you are probably running with parallel testing. Try this:

    (unset AUTHOR_TESTING RELEASE_TESTING HARNESS_OPTIONS;
      cpanm Test::Postgresql58)

Dist::Zilla?

If a better option with equal or greater maturity and community acceptance emerges, I'll entertain changing.

If the requirement of typing "cpanm Dist::Zilla" and using the "dzil" command line tool for a limited number of build jobs prevents you from contributing, I think you are unreasonably stubborn.

If you do contribute to the project, please be aware that I'm not likely to accept patches that include significant changes to the way I'm using Dist::Zilla, including using plugins to weave pod, automagically guess dependencies and generate tests. I'd prefer to stick to the most simple and standard Perl practices for building and installing code for the present.

I don't want my database sandbox files in my source control repository

If you are using "git" you can modify your ".gitignore". If you sandbox is "share/myapp-schema.db" or (if you are using the mysql or postgresql sandboxes) "share/myapp-schema/" you can add these lines to your ".gitignore"

    share/musicbase-schema/*
    share/musicbase-schema.db

Other source control systems have similiar approaches (recipes welcome for sharing).

What's the command to run migrations on an existing database?

    dbic-migration -Ilib status \
      --dsn="DBI:mysql:database=test;host=127.0.0.1;port=5142" \
      --user msandbox \
      --password msandbox

Would be the general approach.

Error: Trouble creating a MySQL Sandbox when running AppArmor

Here's some symptoms of this problem, if you think you may be having it:

In "/var/log/syslog" something like:

    kernel: [18593519.090601] type=1503 audit(1281847667.413:22):
    operation="inode_permission" requested_mask="::r" denied_mask="::r"
    fsuid=0 name="/etc/mysql0/my.cnf" pid=4884 profile="/usr/sbin/mysqld"

If you need AppArmor, you'll have to setup and install MySQL the 'old school way.'

Error: "Failed to find share dir for dist..."

By default we expect to find a "/share" directory in your primary project root directory (contains your "Makefile.PL" or "dist.ini", and the "lib" and "t" directories for example) where we will create migrations. At this time we can't automatically create this "/share" directory in the same way we can create all the migration files and directory for you. You need to create that directory yourself:

    mkdir share

Patches to fix this, or suggestions welcomed.

How to run a Migration Script before changing the Schema

    share/migrations/_common/upgrade/5-6/001_transform.pl
    share/migrations/MySQL/upgrade/5-6/002_auto.sql

Migration will run the upgrades by the Numbers, no matter in which Upgrade Folder they are specified.

Can I use this even if I don't want to use DBIx::Class?

You use a subclass of DBIx::Class::Schema::Loader in a namespace for your application, like:

    package MyApp::Schema;

    use strict;
    use warnings;

    use base 'DBIx::Class::Schema::Loader';

    our $VERSION = 1;

    __PACKAGE__->naming('current');
    __PACKAGE__->use_namespaces(1);
    __PACKAGE__->loader_options( );

    1;

You'd put that in "lib/MyApp/Schema.pm" along with your other application code. then just use "MyApp::Schema" as is discussed in the documentation. This will dynamically build a schema for you, as long as you set the schema arguments to connect to your actual database. Then everytime someone changes the database you just up the $VERSION and take it from there. Obviously this is a bit more manual effort, but at least you can have the ability to populate to any given version, manage fixtures, do some sane testing, etc. Maybe you'll even be able to convince people to try out DBIx::Class!

By the way, if you wanted, you can always dump the generated version of your classes using "make_schema" (see "make_schema" in DBIx::Class::Migration and "make_schema" in DBIx::Class::Migration::Script).

I am using MySQL and when the migration fails, it doesn't ROLLBACK

I need to dump fixtures from a existing database

DBIx::Class::Migration will let you run the "dump_all_sets" and "dump_named_sets" commands against an unversioned database. For example:

    dbic-migration -Ilib -SMyApp::Schema dump_all_sets /
      --dsn="dbi:mysql:database=myapp;host=10.0.88.98;port=3306" /
      --username johnn /
      --password $PASSWORD

In this case let's say "dbi:mysql:database=myapp;host=10.0.88.98;port=3306" is a database that you've been managing manually and it has some data that is useful for creating your fixture sets.

When you run these commands against an unversioned database you will be warned because we have no way of being sure what version of the fixture sets you should be dumping. We will just assume that whatever the Schema version is, is correct. This can of course lead to bad or undumpable fixtures should your Schema and the unversioned DB not match properly. Buyer beware!

How do I specify the character set for a database or table?

  sub sqlt_deploy_hook {
    my ($self, $sqlt_table) = @_;
    $sqlt_table->options({'DEFAULT CHARACTER SET' => 'utf8'});
  }

Error: "`' is not a module name"

    dbic-migration -Ilib -SMyApp::Schema
    dbic-migration -Ilib --schema_class MyApp::Schema

or by exporting the %ENV:

    export DBIC_MIGRATION_SCHEMA_CLASS=MyApp::Schema

Or, if you have a custom version of DBIx::Class::Migration::Script as discussed in the tutorial, you are not providing a good "schema_class" value.

Error: "Attribute (schema_class) does not pass the type constraint"

    dbic-migration -Ilib -SMyApp::Schema [command]

When using the Postgresql Sandbox, I get "FATAL: could not create shared memory segment"

    FATAL:  could not create shared memory segment: Cannot allocate memory
    DETAIL:  Failed system call was shmget(key=1, size=2138112, 03600).
    HINT:  This error usually means that PostgreSQL's request for a shared memory
    segment exceeded available memory or swap space, or exceeded your kernel's
    SHMALL parameter.  You can either reduce the request size or reconfigure
    the kernel with larger SHMALL.  To reduce the request size (currently 2138112
    bytes), reduce PostgreSQL's shared memory usage, perhaps by reducing
    shared_buffers or max_connections.

The solution is as presented. Since I prefer not to change my system settings permanently, just add the following to a little bash script in my application

    sudo sysctl -w kern.sysv.shmall=65536
    sudo sysctl -w kern.sysv.shmmax=16777216

I don't know enough about Postgresql to know if the above settings are good, but they work for my testing. Corrections very welcome! Ideally I'd try to find a way to offer a patch to Test::Postgresql58, although this seems to be limited to people using Macs.

How to Release

Update Version

You need to increment the version in "dist.ini" and in DBIx::Class::Migration

Prepare Changes file

Update the "Changes" file. It would be ideal to have been adding to this as you've gone along, but you should double check.

Update Author's list

If there have been new contributors, be sure to give credit

Rebuild the README

    pod2markdown < lib/DBIx/Class/Migration.pm > README.mkdn
    

This will make sure the "README.mkdn" file in the project root matches the most recent updates.

Check your tests

    AUTHOR_MODE=1 prove -lvr t
    

Update the repository

    git add @stuff_to_add
    git commit -m $message
    git push
    

Make the Distribution

    dzil release
    dzil clean
    

Update the git version tag

I usually don't update and push the tag until we are on CPAN.

    git tag $VERSION -m 'cpan release'
    git push --tags
    

AUTHOR

COPYRIGHT & LICENSE