NetSDS::DBI::Table(3pm)

NAME
NetSDS::DBI::Table

SYNOPSIS
        use NetSDS::DBI::Table;

        my $q = NetSDS::DBI::Table->new(
                dsn    => 'dbi:Pg:dbname=netsdsdb;host=127.0.0.1',
                user   => 'netsds',
                passwd => 'test',
                table  => 'public.messages',
        ) or warn NetSDS::DBI::Table->errstr();

DESCRIPTION
"NetSDS::DBI::Table" module provides commonly used CRUD functionality for data stored in single database.

Main idea was that we can agree about some limitations:

* every such table contains "id" field that is primary key

* we use PostgreSQL DBMS with all it's features

CLASS API

new([...]) - class constructor
            my $tbl = NetSDS::DBI::Table->new(
                    dsn => 'dbi:Pg:dbname=content',
                    login => 'netsds',
                    passwd => 'topsecret,
                    table => 'content.meta',
            );

fetch(%params) - get records from table as array of hashrefs
    Paramters (hash):

    * fields - fetch fields by list

    * filter - arrayref of SQL expressions like "status = 'active'" for "WHERE" clause

    * order - arrayref of SQL expressions like "id desc" for "ORDER BY" clause

    * limit - max number of records to fetch (LIMIT N)

    * offset - records to skip from beginning (OFFSET N)

    * for_update - records selected for further update within current transaction

    Returns: message as array of hashrefs

    Sample:

            my @messages = $q->fetch(
                    fields => ['id', 'now() as time'],
                    filter => ['msg_status = 5', 'date_received < now()'], # where msg_status=5 and date_received < now()
                    order  => ['id desc', 'src_addr'], # order by id desc, src_addr
                    limit => 3, # fetch 3 records
                    offset => 5, # from 6-th record
                    for_update => 1, # for update
            )

insert_row(%key_val_pairs) - insert record into table
    Paramters: record fields as hash

    Returns: id of inserted record

            my $user_id = $tbl->insert_row(
                    'login' => 'vasya',
                    'password' => $encrypted_passwd,
            );

insert(@records_list) - mass insert
    Paramters: list of records (as hashrefs)

    Returns: array of inserted records "id"

    This method allows mass insert of records.

            my @user_ids = $tbl->insert(
                    { login => 'vasya', password => $str1 },
                    { login => 'masha', password => $str2 },
                    { login => 'petya', password => $str3, active => 'false' },
            );

    Warning! This method use separate INSERT queries and in fact is only wrapper for multiple insert_row() calls. So it's not so fast as one insert but allows to use different key-value pairs for different records.

update_row($id, %params) - update record parameters
    Paramters: id, new parameters as hash

    Returns: updated record as hash

    Example:

            my %upd = $table->update_row($msg_id,
                    status => 'failed',
                    dst_addr => '380121234567',
                    );

    After this %upd hash will contain updated table record.

update(%params) - update records by filter
    Paramters: filter, new values

            $tbl->update(
                    filter => ['active = true', 'created > '2008-01-01'],
                    set => {
                            info => 'Created after 2007 year',
                    }
            );

get_count(%params) - retrieve number of records
    Just return total number of records by calling:

            # SELECT COUNT(id) FROM schema.table
            my $count = $tbl->get_count();

            my $count_active = $tbl->get_count(filter => ['active = true']);

delete_by_id(@ids) - delete records by identifier
    Paramters: list of record id

    Returns: 1 if ok, undef if error

    Method deletes records from SQL table by it's identifiers.

            if ($tbl->remove(5, 8 ,19)) {
                    print "Records successfully removed.";
            }

delete(@filters) - delete records
    Paramters: list of filters

    Returns: 1 if ok, undef if error

            $tbl->delete(
                    'active = false',
                    'expire < now()',
            );

get_fields() - get list of fields
    Example:

            my @fields = @{ $tbl->get_fields() };
            print "Table fields: " . join (', ', @fields);

has_field($field) - check if field exists
    Paramters: field name

    Example:

            if ($tbl->has_field('uuid')) {
                    $tbl->call("delete tbldata where uuid=?", $uuid);
            }

    NOTE: this method works only for restricted tables that use "fields" parameter at construction time.

EXAMPLES
See "samples/test_db_table.pl" script

BUGS
Bad documentation

SEE ALSO
NetSDS::DBI

<http://en.wikipedia.org/wiki/Create,_read,_update_and_delete>

TODO
None

AUTHOR
Michael Bochkaryov <misha@rattler.kiev.ua>

LICENSE
Copyright (C) 2008-2009 Net Style Ltd.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA