Nicolas Franck
and 5 contributors

NAME

Catmandu::Store::DBI - A Catmandu::Store plugin for DBI based interfaces

VERSION

Version 0.0424

SYNOPSIS

    # From the command line
    $ catmandu import JSON to DBI --data_source SQLite:mydb.sqlite < data.json

    # From Perl code

    use Catmandu;

    my $store = Catmandu->store('DBI',
        data_source => 'dbi:mysql:database=test', 
        username => 'foo', # optional
        password => 'bar', # optional
    );

    my $obj1 = $store->bag->add({ name => 'Patrick' });

    printf "obj1 stored as %s\n" , $obj1->{_id};

    # Force an id in the store
    my $obj2 = $store->bag->add({ _id => 'test123' , name => 'Nicolas' });

    my $obj3 = $store->bag->get('test123');

    $store->bag->delete('test123');

    $store->bag->delete_all;

    # All bags are iterators
    $store->bag->each(sub { ... });
    $store->bag->take(10)->each(sub { ... });

DESCRIPTION

A Catmandu::Store::DBI is a Perl package that can store data into DBI backed databases. The database as a whole is a 'store' Catmandu::Store. Databases tables are 'bags' (Catmandu::Bag).

Databases need to be preconfigured for accepting Catmandu data. When no specialized Catmandu tables exist in a database then Catmandu will create them automatically. See "DATABASE CONFIGURATION" below.

DO NOT USE Catmandu::Store::DBI on an existing database! Tables and data can be deleted and changed.

CONFIGURATION

data_source

Required. The connection parameters to the database. See DBI for more information.

Examples:

      dbi:mysql:foobar   <= a local mysql database 'foobar'
      dbi:Pg:dbname=foobar;host=myserver.org;port=5432 <= a remote PostGres database
      dbi:SQLite:mydb.sqlite <= a local SQLLite file based database mydb.sqlite
      dbi:Oracle:host=myserver.org;sid=data01 <= a remote Oracle database

Drivers for each database need to be available on your computer. Install then with:

    cpanm DBD::mysql
    cpanm DBD::Pg
    cpanm DBD::SQLite
    cpanm DBD::Oracle
user

Optional. A user name to connect to the database

password

Optional. A password for connecting to the database

timeout

Optional. Timeout for a inactive database handle. When timeout is reached, Catmandu checks if the connection is still alive (by use of ping) or it recreates the connection. See TIMEOUTS below for more information.

reconnect_after_timeout

Optional. When a timeout is reached, Catmandu reconnects to the database. By default set to '0'

DATABASE CONFIGURATION

When no tables exists for storing data in the database, then Catmandu will create them. By default tables are created for each Catmandu::Bag which contain an '_id' and 'data' column.

This behavior can be changed with mapping option:

    my $store = Catmandu::Store::DBI->new(
        data_source => 'DBI:mysql:database=test',
        bags => {
            # books table
            books => {
                mapping => {
                    # these keys will be directly mapped to columns
                    # all other keys will be serialized in the data column
                    title => {type => 'string', required => 1, column => 'book_title'},
                    isbn => {type => 'string', unique => 1},
                    authors => {type => 'string', array => 1}
                }
            }
        }
    );

Column types

string
integer
binary

Column options

column

Name of the table column if it differs from the key in your data.

array

Boolean option, default is 0. Note that this options is only supported for PostgreSQL.

unique

Boolean option, default is 0.

required

Boolean option, default is 0.

TIMEOUT

It is a good practice to set the timeout high enough. When using transactions, one should avoid this situation:

    $bag->store->transaction(sub{
        $bag->add({ _id => "1" });
        sleep $timeout;
        $bag->add({ _id => "2" });
    });

The following warning appears:

    commit ineffective with AutoCommit enabled at lib//Catmandu/Store/DBI.pm line 73.
    DBD::SQLite::db commit failed: attempt to commit on inactive database handle

This has the following reasons:

    1.  first record added
    2.  timeout is reached, the connection is recreated
    3.  the option AutoCommit is set. So the database handle commits the current transaction. The first record is committed.
    4.  this new connection handle is used now. We're still in the method "transaction", but there is no longer a real transaction at database level.
    5.  second record is added (committed)
    6.  commit is issued. But this unnecessary, so the database handle throws a warning.

SEE ALSO

Catmandu::Bag, Catmandu::Searchable, DBI