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