package DBI::Custom;

use Object::Simple;

our $VERSION = '0.0101';

use Carp 'croak';

use DBI;

use DBI::Custom::Query;

use DBI::Custom::Result;

use DBI::Custom::SQL::Template;

### Class-Object Accessors

sub user        : ClassObjectAttr { initialize => {clone => 'scalar'} }

sub password    : ClassObjectAttr { initialize => {clone => 'scalar'} }

sub data_source : ClassObjectAttr { initialize => {clone => 'scalar'} }

sub dbi_options : ClassObjectAttr { initialize => {clone => 'hash', 

                                                   default => sub { {} } } }

sub bind_filter  : ClassObjectAttr { initialize => {clone => 'scalar'} }

sub fetch_filter : ClassObjectAttr { initialize => {clone => 'scalar'} }

sub no_bind_filters   : ClassObjectAttr { initialize => {clone => 'array'} }

sub no_fetch_filters  : ClassObjectAttr { initialize => {clone => 'array'} }

sub filters : ClassObjectAttr {

    type => 'hash',

    deref => 1,

    initialize => {

        clone   => 'hash',

        default => sub { {} }

    }

}

sub formats : ClassObjectAttr {

    type => 'hash',

    deref => 1,

    initialize => {

        clone   => 'hash',

        default => sub { {} }

    }

}

sub result_class : ClassObjectAttr {

    initialize => {

        clone   => 'scalar',

        default => 'DBI::Custom::Result'

    }

}

sub sql_template : ClassObjectAttr {

    initialize => {

        clone   => sub {$_[0] ? $_[0]->clone : undef},

        default => sub {DBI::Custom::SQL::Template->new}

    }

}

### Object Accessor

sub dbh          : Attr {}

### Methods

# Add filter

sub add_filter {

    my $invocant = shift;

    my %old_filters = $invocant->filters;

    my %new_filters = ref $_[0] eq 'HASH' ? %{$_[0]} : @_;

    $invocant->filters(%old_filters, %new_filters);

    return $invocant;

}

# Add format

sub add_format{

    my $invocant = shift;

    my %old_formats = $invocant->formats;

    my %new_formats = ref $_[0] eq 'HASH' ? %{$_[0]} : @_;

    $invocant->formats(%old_formats, %new_formats);

    return $invocant;

}

# Auto commit

sub _auto_commit {

    my $self = shift;

    croak("Not yet connect to database") unless $self->dbh;

    if (@_) {

        $self->dbh->{AutoCommit} = $_[0];

        return $self;

    }

    return $self->dbh->{AutoCommit};

}

# Connect

sub connect {

    my $self = shift;

    my $data_source = $self->data_source;

    my $user        = $self->user;

    my $password    = $self->password;

    my $dbi_options  = $self->dbi_options;

    my $dbh = eval{DBI->connect(

        $data_source,

        $user,

        $password,

        {

            RaiseError => 1,

            PrintError => 0,

            AutoCommit => 1,

            %{$dbi_options || {} }

        }

    )};

    croak $@ if $@;

    $self->dbh($dbh);

    return $self;

}

# DESTROY

sub DESTROY {

    my $self = shift;

    $self->disconnect if $self->connected;

}

# Is connected?

sub connected {

    my $self = shift;

    return ref $self->{dbh} eq 'DBI::db';

}

# Disconnect

sub disconnect {

    my $self = shift;

    if ($self->connected) {

        $self->dbh->disconnect;

        delete $self->{dbh};

    }

}

# Reconnect

sub reconnect {

    my $self = shift;

    $self->disconnect if $self->connected;

    $self->connect;

}

# Prepare statement handle

sub prepare {

    my ($self, $sql) = @_;

    # Connect if not

    $self->connect unless $self->connected;

    # Prepare

    my $sth = eval{$self->dbh->prepare($sql)};

    # Error

    croak("$@<Your SQL>\n$sql") if $@;

    return $sth;

}

# Execute SQL directly

sub do{

    my ($self, $sql, @bind_values) = @_;

    # Connect if not

    $self->connect unless $self->connected;

    # Do

    my $ret_val = eval{$self->dbh->do($sql, @bind_values)};

    # Error

    if ($@) {

        my $error = $@;

        require Data::Dumper;

        my $bind_value_dump

          = Data::Dumper->Dump([\@bind_values], ['*bind_valuds']);

        croak("$error<Your SQL>\n$sql\n<Your bind values>\n$bind_value_dump\n");

    }

}

# Create query

sub create_query {

    my ($self, $template) = @_;

    my $class = ref $self;

    # Create query from SQL template

    my $sql_template = $self->sql_template;

    # Try to get cached query

    my $query = $class->_query_caches->{$template};

    # Create query

    unless ($query) {

        $query = eval{$sql_template->create_query($template)};

        croak($@) if $@;

        $query = DBI::Custom::Query->new($query);

        $class->_add_query_cache($template, $query);

    }

    # Connect if not

    $self->connect unless $self->connected;

    # Prepare statement handle

    my $sth = $self->prepare($query->{sql});

    # Set statement handle

    $query->sth($sth);

    # Set bind filter

    $query->bind_filter($self->bind_filter);

    # Set no filter keys when binding

    $query->no_bind_filters($self->no_bind_filters);

    # Set fetch filter

    $query->fetch_filter($self->fetch_filter);

    # Set no filter keys when fetching

    $query->no_fetch_filters($self->no_fetch_filters);

    return $query;

}

# Execute query

sub execute {

    my ($self, $query, $params)  = @_;

    $params ||= {};

    # First argument is SQL template

    if (!ref $query) {

        my $template = $query;

        $query = $self->create_query($template);

        my $query_edit_cb = $_[3];

        $query_edit_cb->($query) if ref $query_edit_cb eq 'CODE';

    }

    # Create bind value

    my $bind_values = $self->_build_bind_values($query, $params);

    # Execute

    my $sth = $query->sth;

    my $ret_val = eval{$sth->execute(@$bind_values)};

    # Execute error

    if (my $execute_error = $@) {

        require Data::Dumper;

        my $sql              = $query->{sql} || '';

        my $key_infos_dump   = Data::Dumper->Dump([$query->key_infos], ['*key_infos']);

        my $params_dump      = Data::Dumper->Dump([$params], ['*params']);

        croak("$execute_error" . 

              "<Your SQL>\n$sql\n" . 

              "<Your parameters>\n$params_dump");

    }

    # Return resultset if select statement is executed

    if ($sth->{NUM_OF_FIELDS}) {

        # Get result class

        my $result_class = $self->result_class;

        # Create result

        my $result = $result_class->new({

            sth              => $sth,

            fetch_filter     => $query->fetch_filter,

            no_fetch_filters => $query->no_fetch_filters

        });

        return $result;

    }

    return $ret_val;

}

# Build binding values

sub _build_bind_values {

    my ($self, $query, $params) = @_;

    my $key_infos           = $query->key_infos;

    my $bind_filter         = $query->bind_filter;

    my $no_bind_filters_map = $query->_no_bind_filters_map || {};

    # binding values

    my @bind_values;

    # Create bind values

    KEY_INFOS :

    foreach my $key_info (@$key_infos) {

        # Set variable

        my $access_keys  = $key_info->{access_keys};

        my $original_key = $key_info->{original_key} || '';

        my $table        = $key_info->{table}        || '';

        my $column       = $key_info->{column}       || '';

        # Key is found?

        my $found;

        # Build bind values

        ACCESS_KEYS :

        foreach my $access_key (@$access_keys) {

            # Root parameter

            my $root_params = $params;

            # Search corresponding value

            for (my $i = 0; $i < @$access_key; $i++) {

                # Current key

                my $current_key = $access_key->[$i];

                # Last key

                if ($i == @$access_key - 1) {

                    # Key is array reference

                    if (ref $current_key eq 'ARRAY') {

                        # Filtering 

                        if ($bind_filter &&

                            !$no_bind_filters_map->{$original_key})

                        {

                            push @bind_values, 

                                 $bind_filter->($original_key, 

                                                $root_params->[$current_key->[0]],

                                                $table, $column);

                        }

                        # Not filtering

                        else {

                            push @bind_values,

                                 scalar $root_params->[$current_key->[0]];

                        }

                    }

                    # Key is string

                    else {

                        # Key is not found

                        next ACCESS_KEYS

                          unless exists $root_params->{$current_key};

                        # Filtering

                        if ($bind_filter &&

                            !$no_bind_filters_map->{$original_key}) 

                        {

                            push @bind_values,

                                 $bind_filter->($original_key,

                                                $root_params->{$current_key}, 

                                                $table, $column);

                        }

                        # Not filtering

                        else {

                            push @bind_values,

                                 scalar $root_params->{$current_key};

                        }

                    }

                    # Key is found

                    $found = 1;

                    next KEY_INFOS;

                }

                # First or middle key

                else {

                    # Key is array reference

                    if (ref $current_key eq 'ARRAY') {

                        # Go next key

                        $root_params = $root_params->[$current_key->[0]];

                    }

                    # Key is string

                    else {

                        # Not found

                        next ACCESS_KEYS

                          unless exists $root_params->{$current_key};

                        # Go next key

                        $root_params = $root_params->{$current_key};

                    }

                }

            }

        }

        # Key is not found

        unless ($found) {

            require Data::Dumper;

            my $key_info_dump  = Data::Dumper->Dump([$key_info], ['*key_info']);

            my $params_dump    = Data::Dumper->Dump([$params], ['*params']);

            croak("Corresponding key is not found in your parameters\n" . 

                  "<Key information>\n$key_info_dump\n\n" .

                  "<Your parameters>\n$params_dump\n");

        }

    }

    return \@bind_values;

}

# Run tranzaction

sub run_tranzaction {

    my ($self, $tranzaction) = @_;

    # Check auto commit

    croak("AutoCommit must be true before tranzaction start")

      unless $self->_auto_commit;

    # Auto commit off

    $self->_auto_commit(0);

    # Run tranzaction

    eval {$tranzaction->()};

    # Tranzaction error

    my $tranzaction_error = $@;

    # Tranzaction is failed.

    if ($tranzaction_error) {

        # Rollback

        eval{$self->dbh->rollback};

        # Rollback error

        my $rollback_error = $@;

        # Auto commit on

        $self->_auto_commit(1);

        if ($rollback_error) {

            # Rollback is failed

            croak("${tranzaction_error}Rollback is failed : $rollback_error");

        }

        else {

            # Rollback is success

            croak("${tranzaction_error}Rollback is success");

        }

    }

    # Tranzaction is success

    else {

        # Commit

        eval{$self->dbh->commit};

        my $commit_error = $@;

        # Auto commit on

        $self->_auto_commit(1);

        # Commit is failed

        croak($commit_error) if $commit_error;

    }

}

# Get last insert id

sub last_insert_id {

    my $self = shift;

    # Not connected

    croak("Not yet connect to database")

      unless $self->connected;

    return $self->dbh->last_insert_id(@_);

}

# Insert

sub insert {

    my ($self, $table, $insert_params, $query_edit_cb) = @_;

    $table         ||= '';

    $insert_params ||= {};

    # Insert keys

    my @insert_keys = keys %$insert_params;

    # Not exists insert keys

    croak("Key-value pairs for insert must be specified to 'insert' second argument")

      unless @insert_keys;

    # Templte for insert

    my $template = "insert into $table {insert " . join(' ', @insert_keys) . '}';

    # Create query

    my $query = $self->create_query($template);

    # Query edit callback must be code reference

    croak("Query edit callback must be code reference")

      if $query_edit_cb && ref $query_edit_cb ne 'CODE';

    # Query edit if need

    $query_edit_cb->($query) if $query_edit_cb;

    # Execute query

    my $ret_val = $self->execute($query, $insert_params);

    return $ret_val;

}

# Update

sub update {

    my ($self, $table, $update_params,

        $where_params, $query_edit_cb, $options) = @_;

    $table         ||= '';

    $update_params ||= {};

    $where_params  ||= {};

    # Update keys

    my @update_keys = keys %$update_params;

    # Not exists update kyes

    croak("Key-value pairs for update must be specified to 'update' second argument")

      unless @update_keys;

    # Where keys

    my @where_keys = keys %$where_params;

    # Not exists where keys

    croak("Key-value pairs for where clause must be specified to 'update' third argument")

      if !@where_keys && !$options->{allow_update_all};

    # Update clause

    my $update_clause = '{update ' . join(' ', @update_keys) . '}';

    # Where clause

    my $where_clause = '';

    if (@where_keys) {

        $where_clause = 'where ';

        foreach my $where_key (@where_keys) {

            $where_clause .= "{= $where_key} and ";

        }

        $where_clause =~ s/ and $//;

    }

    # Template for update

    my $template = "update $table $update_clause $where_clause";

    # Create query

    my $query = $self->create_query($template);

    # Query edit callback must be code reference

    croak("Query edit callback must be code reference")

      if $query_edit_cb && ref $query_edit_cb ne 'CODE';

    # Query edit if need

    $query_edit_cb->($query) if $query_edit_cb;

    # Rearrange parammeters

    my $params = {'#update' => $update_params, %$where_params};

    # Execute query

    my $ret_val = $self->execute($query, $params);

    return $ret_val;

}

# Update all rows

sub update_all {

    my ($self, $table, $update_params, $query_edit_cb) = @_;

    return $self->update($table, $update_params, {}, $query_edit_cb,

                         {allow_update_all => 1});

}

# Delete

sub delete {

    my ($self, $table, $where_params, $query_edit_cb, $options) = @_;

    $table        ||= '';

    $where_params ||= {};

    # Where keys

    my @where_keys = keys %$where_params;

    # Not exists where keys

    croak("Key-value pairs for where clause must be specified to 'delete' second argument")

      if !@where_keys && !$options->{allow_delete_all};

    # Where clause

    my $where_clause = '';

    if (@where_keys) {

        $where_clause = 'where ';

        foreach my $where_key (@where_keys) {

            $where_clause .= "{= $where_key} and ";

        }

        $where_clause =~ s/ and $//;

    }

    # Template for delete

    my $template = "delete from $table $where_clause";

    # Create query

    my $query = $self->create_query($template);

    # Query edit callback must be code reference

    croak("Query edit callback must be code reference")

      if $query_edit_cb && ref $query_edit_cb ne 'CODE';

    # Query edit if need

    $query_edit_cb->($query) if $query_edit_cb;

    # Execute query

    my $ret_val = $self->execute($query, $where_params);

    return $ret_val;

}

# Delete all rows

sub delete_all {

    my ($self, $table) = @_;

    return $self->delete($table, {}, undef, {allow_delete_all => 1});

}

sub _select_usage { return << 'EOS' }

Your select arguments is wrong.

select usage:

$dbi->select(

    $table,                # must be string or array ref

    [@$columns],           # must be array reference. this is optional

    {%$where_params},      # must be hash reference.  this is optional

    $append_statement,     # must be string.          this is optional

    $query_edit_callback   # must be code reference.  this is optional

);

EOS

sub select {

    my $self = shift;

    # Check argument

    croak($self->_select_usage) unless @_;

    # Arguments

    my $tables = shift || '';

    $tables    = [$tables] unless ref $tables;

    my $columns          = ref $_[0] eq 'ARRAY' ? shift : [];

    my $where_params     = ref $_[0] eq 'HASH'  ? shift : {};

    my $append_statement = $_[0] && !ref $_[0]  ? shift : '';

    my $query_edit_cb    = shift if ref $_[0] eq 'CODE';

    # Check rest argument

    croak($self->_select_usage) if @_;

    # SQL template for select statement

    my $template = 'select ';

    # Join column clause

    if (@$columns) {

        foreach my $column (@$columns) {

            $template .= "$column, ";

        }

        $template =~ s/, $/ /;

    }

    else {

        $template .= '* ';

    }

    # Join table

    $template .= 'from ';

    foreach my $table (@$tables) {

        $template .= "$table, ";

    }

    $template =~ s/, $/ /;

    # Where clause keys

    my @where_keys = keys %$where_params;

    # Join where clause

    if (@where_keys) {

        $template .= 'where ';

        foreach my $where_key (@where_keys) {

            $template .= "{= $where_key} and ";

        }

    }

    $template =~ s/ and $//;

    # Append something to last of statement

    if ($append_statement =~ s/^where //) {

        if (@where_keys) {

            $template .= " and $append_statement";

        }

        else {

            $template .= " where $append_statement";

        }

    }

    else {

        $template .= " $append_statement";

    }

    # Create query

    my $query = $self->create_query($template);

    # Query edit

    $query_edit_cb->($query) if $query_edit_cb;

    # Execute query

    my $result = $self->execute($query, $where_params);

    return $result;

}

sub _query_caches     : ClassAttr { type => 'hash',

                                    auto_build => sub {shift->_query_caches({}) } }

sub _query_cache_keys : ClassAttr { type => 'array',

                                    auto_build => sub {shift->_query_cache_keys([])} }

sub query_cache_max   : ClassAttr { auto_build => sub {shift->query_cache_max(50)} }

# Add query cahce

sub _add_query_cache {

    my ($class, $template, $query) = @_;

    my $query_cache_keys = $class->_query_cache_keys;

    my $query_caches     = $class->_query_caches;

    return $class if $query_caches->{$template};

    $query_caches->{$template} = $query;

    push @$query_cache_keys, $template;

    my $overflow = @$query_cache_keys - $class->query_cache_max;

    for (my $i = 0; $i < $overflow; $i++) {

        my $template = shift @$query_cache_keys;

        delete $query_caches->{$template};

    }

    return $class;

}

Object::Simple->build_class;

=head1 NAME

DBI::Custom - Customizable simple DBI

=head1 VERSION

Version 0.0101

=head1 CAUTION

This module is now experimental stage.

I want you to try this module

because I want this module stable, and not to damage your DB data by this module bug.

Please tell me bug if you find

=head1 SYNOPSIS

  my $dbi = DBI::Custom->new;

  my $query = $dbi->create_query($template);

  $dbi->execute($query);

=head1 CLASS-OBJECT ACCESSORS

=head2 user

    # Set and get database user name

    $self = $dbi->user($user);

    $user = $dbi->user;

    # Sample

    $dbi->user('taro');

=head2 password

    # Set and get database password

    $self     = $dbi->password($password);

    $password = $dbi->password;

    # Sample

    $dbi->password('lkj&le`@s');

=head2 data_source

    # Set and get database data source

    $self        = $dbi->data_source($data_soruce);

    $data_source = $dbi->data_source;

    # Sample(SQLite)

    $dbi->data_source(dbi:SQLite:dbname=$database);

    # Sample(MySQL);

    $dbi->data_source("dbi:mysql:dbname=$database");

    # Sample(PostgreSQL)

    $dbi->data_source("dbi:Pg:dbname=$database");

=head2 database

    # Set and get database name

    $self     = $dbi->database($database);

    $database = $dbi->database;

=head2 dbi_options

    # Set and get DBI option

    $self       = $dbi->dbi_options({$options => $value, ...});

    $dbi_options = $dbi->dbi_options;

    # Sample

    $dbi->dbi_options({PrintError => 0, RaiseError => 1});

dbi_options is used when you connect database by using connect.

=head2 prepare

    $sth = $dbi->prepare($sql);

This method is same as DBI::prepare

=head2 do

    $dbi->do($sql, @bind_values);

This method is same as DBI::do

=head2 sql_template

    # Set and get SQL::Template object

    $self         = $dbi->sql_template($sql_template);

    $sql_template = $dbi->sql_template;

    # Sample

    $dbi->sql_template(DBI::Cutom::SQL::Template->new);

=head2 filters

    # Set and get filters

    $self    = $dbi->filters($filters);

    $filters = $dbi->filters;

=head2 formats

    # Set and get formats

    $self    = $dbi->formats($formats);

    $formats = $dbi->formats;

=head2 bind_filter

    # Set and get binding filter

    $self        = $dbi->bind_filter($bind_filter);

    $bind_filter = $dbi->bind_filter

    # Sample

    $dbi->bind_filter($self->filters->{default_bind_filter});

you can get DBI database handle if you need.

=head2 fetch_filter

    # Set and get Fetch filter

    $self         = $dbi->fetch_filter($fetch_filter);

    $fetch_filter = $dbi->fetch_filter;

    # Sample

    $dbi->fetch_filter($self->filters->{default_fetch_filter});

=head2 no_bind_filters

    # Set and get no filter keys when binding

    $self            = $dbi->no_bind_filters($no_bind_filters);

    $no_bind_filters = $dbi->no_bind_filters;

=head2 no_fetch_filters

    # Set and get no filter keys when fetching

    $self             = $dbi->no_fetch_filters($no_fetch_filters);

    $no_fetch_filters = $dbi->no_fetch_filters;

=head2 result_class

    # Set and get resultset class

    $self         = $dbi->result_class($result_class);

    $result_class = $dbi->result_class;

    # Sample

    $dbi->result_class('DBI::Custom::Result');

=head2 dbh

    # Get database handle

    $dbh = $self->dbh;

=head1 METHODS

=head2 connect

    # Connect to database

    $self = $dbi->connect;

    # Sample

    $dbi = DBI::Custom->new(user => 'taro', password => 'lji8(', 

                            data_soruce => "dbi:mysql:dbname=$database");

    $dbi->connect;

=head2 disconnect

    # Disconnect database

    $dbi->disconnect;

If database is already disconnected, this method do noting.

=head2 reconnect

    # Reconnect

    $dbi->reconnect;

=head2 connected

    # Check connected

    $dbi->connected

=head2 add_filter

    # Add filter (hash ref or hash can be recieve)

    $self = $dbi->add_filter({$filter_name => $filter, ...});

    $self = $dbi->add_filter($filetr_name => $filter, ...);

    # Sample

    $dbi->add_filter(

        decode_utf8 => sub {

            my ($key, $value, $table, $column) = @_;

            return Encode::decode('UTF-8', $value);

        },

        datetime_to_string => sub {

            my ($key, $value, $table, $column) = @_;

            return $value->strftime('%Y-%m-%d %H:%M:%S')

        },

        default_bind_filter => sub {

            my ($key, $value, $table, $column) = @_;

            if (ref $value eq 'Time::Piece') {

                return $dbi->filters->{datetime_to_string}->($value);

            }

            else {

                return $dbi->filters->{decode_utf8}->($value);

            }

        },

        encode_utf8 => sub {

            my ($key, $value) = @_;

            return Encode::encode('UTF-8', $value);

        },

        string_to_datetime => sub {

            my ($key, $value) = @_;

            return DateTime::Format::MySQL->parse_datetime($value);

        },

        default_fetch_filter => sub {

            my ($key, $value, $type, $sth, $i) = @_;

            if ($type eq 'DATETIME') {

                return $dbi->filters->{string_to_datetime}->($value);

            }

            else {

                return $dbi->filters->{encode_utf8}->($value);

            }

        }

    );

add_filter add filter to filters

=head2 add_format

    $dbi->add_format(date => '%Y:%m:%d');

=head2 create_query

    # Create Query object from SQL template

    my $query = $dbi->create_query($template);

=head2 execute

    # Parse SQL template and execute SQL

    $result = $dbi->query($query, $params);

    $result = $dbi->query($template, $params); # Shorcut

    # Sample

    $result = $dbi->query("select * from authors where {= name} and {= age}", 

                          {author => 'taro', age => 19});

    while (my @row = $result->fetch) {

        # do something

    }

See also L<DBI::Custom::SQL::Template>

=head2 run_tranzaction

    # Run tranzaction

    $dbi->run_tranzaction(sub {

        # do something

    });

If tranzaction is success, commit is execute. 

If tranzation is died, rollback is execute.

=head2 insert

    # Insert

    $dbi->insert($table, $insert_values);

    # Sample

    $dbi->insert('books', {title => 'Perl', author => 'Taro'});

=head2 update

    # Update

    $dbi->update($table, $update_values, $where);

    # Sample

    $dbi->update('books', {title => 'Perl', author => 'Taro'}, {id => 5});

=head2 update_all

    # Update all rows

    $dbi->update($table, $updat_values);

=head2 delete

    # Delete

    $dbi->delete($table, $where);

    # Sample

    $dbi->delete('Books', {id => 5});

=head2 delete_all

    # Delete all rows

    $dbi->delete_all($table);

=head2 last_insert_id

    # Get last insert id

    $last_insert_id = $dbi->last_insert_id;

This method is same as DBI last_insert_id;

=head2 select

    # Select

    $dbi->select(

        $table,                # must be string or array;

        [@$columns],           # must be array reference. this is optional

        {%$where_params},      # must be hash reference.  this is optional

        $append_statement,     # must be string.          this is optional

        $query_edit_callback   # must be code reference.  this is optional

    );

    # Sample

    $dbi->select(

        'Books',

        ['title', 'author'],

        {id => 1},

        "for update",

        sub {

            my $query = shift;

            $query->bind_filter(sub {

                # ...

            });

        }

    );

    # The way to join multi tables

    $dbi->select(

        ['table1', 'table2'],

        ['table1.id as table1_id', 'title'],

        {table1.id => 1},

        "where table1.id = table2.id",

    );

=head1 Class Accessors

=head2 query_cache_max

    # Max query cache count

    $class           = $class->query_cache_max($query_cache_max);

    $query_cache_max = $class->query_cache_max;

    # Sample

    DBI::Custom->query_cache_max(50);

=head1 CAUTION

DBI::Custom have DIB object internal.

This module is work well in the following DBI condition.

    1. AutoCommit is true

    2. RaiseError is true

By default, Both AutoCommit and RaiseError is true.

You must not change these mode not to damage your data.

If you change these mode, 

you cannot get correct error message, 

or run_tranzaction may fail.

=head1 AUTHOR

Yuki Kimoto, C<< <kimoto.yuki at gmail.com> >>

Github L<http://github.com/yuki-kimoto>

=head1 COPYRIGHT & LICENSE

Copyright 2009 Yuki Kimoto, all rights reserved.

This program is free software; you can redistribute it and/or modify it

under the same terms as Perl itself.

=cut