=encoding utf8

=head1 NAME

DBIx::Custom::Guide - DBIx::Custom Guide

=head1 GUIDE

B<This guide is now writing.>

L<DBIx::Custom> is the class to make easy to execute SQL.

This is L<DBI> wrapper class like L<DBIx::Class> or L<DBIx::Simple>.

You can do thing more easy than L<DBIx::Class>, more flexible

than L<DBIx::Simple>.

L<DBIx::Custom> is B<not< O/R mapper, O/R mapper is usefule, but

you must learn many things. Created SQL is sometimes inefficient,

and in many cases you create raw SQL because

O/R mapper can't make complex SQL

L<DBIx::Custom> is opposit of O/R mapper.

The main purpose is that we respect SQL

and make easy difficult works if you use only L<DBI>.

If you already learn SQL, it is easy to use L<DBIx::Custom>.

I explain L<DBIx::Custom> a little in this section.

In L<DBIx::Custom>, you embbed tag in SQL.

    select * from book where {= title} and {=author};

The part arround {} is tag.

This SQL is converted to the one which contains place holder.

    select * from book where title = ? and author = ?;

Maybe you ask me that this conversion is meaningful.

On the top of this, usuful features is implemented.

See the following descriptions.

=over 4

=item 1. Specify place holder binding value as hash refernce

If you use L<DBI>, you must specify place holder binding value

as array.

    $sth->execute(@bind);

If you use L<DBIx::Custom>, you specify it as hash reference.

    my $param = {title => 'Perl', author => 'Ken'};

    $dbi->execute($sql, $param);

=item 2. Filtering

L<DBIx::Custom> provides filtering system.

For example, You think that about date value you want to 

manipulate it as date object like L<Time::Piece> in Perl,

and want to convert it to database DATE format.

and want to do reverse.

You can use filtering system.

At first, register filter.

    $dbi->register_filter(

        tp_to_date => sub {

            ...

        },

        date_to_tp => sub {

            ...

        }

    );

next, apply this filter to each column.

    $dbi->apply_filter('book',

        'issue_date' => {out => 'tp_to_date', in => 'date_to_tp'}

    );

C<out> is perl-to-database way. C<in> is perl-from-database way.

This filter is automatically enabled in many method.

    $dbi->insert(table => 'book', param => {issue_date => $tp});

=item 3. Selective search condition

It is difficult to create selective where clause in L<DBI>.

For example, If C<title> and C<author> is specified, we create 

the following SQL.

    select * from book where title = ? and author = ?;

If only C<title> is specified, the following one

    select * from book where title = ?;

If only C<author> is specified, the following one,

    select * from book where author = ?;

This is hard work. Generally we use modules like L<SQL::Abstract>.

L<DBIx::Custom> prepare the way to make it easy.

    # Where object

    my $where = $dbi->where;

    # Search condition

    $where->clause(

        ['and', '{= title}', {'= author'}]

    );

    # Setting to automatically select needed column

    $where->param({title => 'Perl'});

    # Embbed where clause to SQL

    my $sql = "select * from book $where";

You can create where clause which has selected search condition.

You can write nesting of where clause and C<or> condition

=item 4. Methods for insert, update, delete, select

L<DBIx::Custom> provides methods for insert, update, delete, select

There are C<insert()>, C<update()>, C<delete()>,C<select()>.

    my $param = {title => 'Perl', author => 'Ken'};

    $dbi->insert(table => 'book', param => $param);

=item 5. Register method for table.

You can register method for table.

    $dbi->table('book')->method(

        list => sub {

            ...

        },

        something => sub {

            ...

        }

    );

use the mehtod.

    $dbi->table('book')->list;

Many O/R mapper must create class for table,

but L<DBIx::Custom> make it easy.

=back

L<DBIx::Custom> is very useful.

See the following if you are interested in it.

=head2 1. Connect to database

Load L<DBIx::Custom>.

    use DBIx::Custom;

use C<connect()> to connect to database.

Return value is L<DBIx::Custom> object.

    my $dbi = DBIx::Custom->connect(

        data_source => "dbi:mysql:database=bookstore",

        user => 'ken',

        password => '!LFKD%$&',

        dbi_options => {mysql_enable_utf8 => 1}

    );

C<data_source> must be one corresponding to the database system.

The following ones are data source example.

B<MySQL>

    "dbi:mysql:database=$database"

    "dbi:mysql:database=$database;host=$hostname;port=$port"

B<SQLite>

    "dbi:SQLite:dbname=$database"

    "dbi:SQLite:dbname=:memory:"

B<PostgreSQL>

    "dbi:Pg:dbname=$dbname"

B<Oracle>

    "dbi:Oracle:$dbname"

    "dbi:Oracle:host=$host;sid=$sid"

B<ODBC(Microsoft Access)>

    "dbi:ODBC:driver=Microsoft Access Driver (*.mdb);dbq=hoge.mdb"

B<ODBC(SQL Server)>

   "dbi:ODBC:driver={SQL Server};Server=(local);database=test;Trusted_Connection=yes;AutoTranslate=No;"

If authentication is needed, you can specify C<user> and C<password>

L<DBIx::Custom> is wrapper class of L<DBI>.

You can use all methods of L<DBI> from L<DBIx::Custom> object.

    $dbi->do(...);

    $dbi->begin_work;

use C<dhb()> to get database handle of L<DBI>

    my $dbh = $dbi->dbh;

By default, the following ones is set to database handle attributes.

    RaiseError  ->  1

    PrintError  ->  0

    AutoCommit  ->  1

If fatal error occuer, program terminate.

If SQL is executed, commit is executed automatically.

=head2 2. Methods for insert, update, delete, or insert

There are following methods.

=head3 C<insert()>

use C<insert()> to insert row into database

    $dbi->insert(table  => 'book',

                 param  => {title => 'Perl', author => 'Ken'});

C<table> is table name, C<param> is insert data.

Following SQL is executed.

    insert into (title, author) values (?, ?);

=head3 C<update()>

use C<update()> to update row in database.

    $dbi->update(table  => 'book', 

                 param  => {title => 'Perl', author => 'Ken'}, 

                 where  => {id => 5});

C<table> is table name, C<param> is update data, C<where> is condition.

Following SQL is executed.

    update book set title = ?, author = ?;

You can't execute C<update()> without C<where> for safety.

use C<update_all()> if you want to update all rows.

    $dbi->update_all(table  => 'book', 

                     param  => {title => 'Perl', author => 'Ken'});

=head3 C<delete()>

use C<delete()> to delete rows from database.

    $dbi->delete(table  => 'book',

                 where  => {author => 'Ken'});

C<table> is table name, C<where> is condition.

Following SQL is executed.

    delete from book where id = ?;

You can't execute C<delete()> without C<where> for safety.

use C<delete_all()> if you want to delete all rows.

    $dbi->delete_all(table  => 'book');

=head3 C<select()>

use C<select()> to select rows from database

    my $result = $dbi->select(table => 'book');

Following SQL is executed.

    select * from book;

Return value is L<DBIx::Custom::Result> object.

use C<fetch()> to fetch row.

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

        my $title  = $row->[0];

        my $author = $row->[1];

    }

See L<3. Fetch row/"3. Fetch row"> about L<DBIx::Custom::Result>.

Continue more examples.

    my $result = $dbi->select(

        table  => 'book',

        column => ['author',  'title'],

        where  => {author => 'Ken'}

    );

C<column> is column names, C<where> is condition.

Following SQL is executed.

    select author, title from book where author = ?;

Next example.

    my $result = $dbi->select(

        table    => ['book', 'rental'],

        where    => {'book.name' => 'Perl'},

        relation => {'book.id' => 'rental.book_id'}

    );

C<relation> is relation of tables. This is inner join.

Following SQL is executed.

    select * from book, rental where book.name = ? and book.id = rental.book_id;

Next example.

    my $result = $dbi->select(

        table  => 'book',

        where  => {author => 'Ken'},

        append => 'for update',

    );

C<append> is string appending to end of SQL.

Following SQL is executed.

    select * book where author = ? for update;

C<appned> is also used at C<insert()>, C<update()>, C<update_all()>

C<delete()>, C<delete_all()>, and C<select()>.

Instead of C<column> and C<table>,

you can use C<selection>.

This is used to specify column names and table names at once

    my $selection = <<"EOS";

    title, author, company_name

    from book inner join company on book.company_id = company.id

    EOS

    $dbi->select(selection => $selection);

Note that you can't use where clause in C<selection>.

use clause like "inner join".

=head3 C<execute()> SQL

use C<execute()> to execute SQL

    $dbi->execute("select * from book;");

Process tag and execute SQL.

    $dbi->execute(

        "select * from book {= title} and {= author};"

        param => {title => 'Perl', author => 'Ken'}

    );

Following SQL is executed.

    select * from book title = ? and author = ?;

Values of title and author is embbdeded into placeholder.

See L<5. Tag/"5. Tag"> about tag.

You don't have to wirte last semicolon in C<execute()>. 

    $dbi->execute('select * from book');

=head2 3. Fetch row

Return value of C<select()> is L<DBIx::Custom::Result> object.

There are many methods to fetch row.

=head3 Fetch a row (array) C<fetch()>

use C<fetch()> to fetch a row and assign it into array reference.

    my $row = $result->fetch;

You can get all rows.

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

        my $title  = $row->[0];

        my $author = $row->[1];

    }

=head3 Fetch only first row (array) C<fetch_first()>

use C<fetch_first()> to fetch only first row.

    my $row = $result->fetch_first;

You can't fetch rest rows

because statement handle C<finish()> is executed.

=head3 Fetch rows (array) C<fetch_multi()>

use C<fetch_multi()> to fetch rows and assign it into

array reference which has array references as element.

    while (my $rows = $result->fetch_multi(2)) {

        my $title0   = $rows->[0][0];

        my $author0  = $rows->[0][1];

        my $title1   = $rows->[1][0];

        my $author1  = $rows->[1][1];

    }

Specify row count as argument.

You can get the following data.

    [

        ['Perl', 'Ken'],

        ['Ruby', 'Mark']

    ]

=head3 Fetch all rows (array) C<fetch_all>

use C<fetch_all()> to fetch all rows and assign it into

array reference which has array reference as element.

    my $rows = $result->fetch_all;

You can get the following data.

    [

        ['Perl', 'Ken'],

        ['Ruby', 'Mark']

    ]

=head3 Fetch a row (hash) C<fetch_hash()>

use C<fetch_hash()> to fetch a row and assign it into hash reference.

    while (my $row = $result->fetch_hash) {

        my $title  = $row->{title};

        my $author = $row->{author};

    }

=head3 Fetch only first row (hash) C<fetch_hash_first()>

use C<fetch_hash_first()> to fetch only first row

and assign it into hash reference.

    my $row = $result->fetch_hash_first;

You can't fetch rest rows

because statement handle C<finish()> is executed.

=head3 Fetch rows (hash) C<fetch_hash_multi()>

use C<fetch_hash_multi()> to fetch rows and

assign it into array reference which has hash references as element.

    while (my $rows = $result->fetch_hash_multi(5)) {

        my $title0   = $rows->[0]{title};

        my $author0  = $rows->[0]{author};

        my $title1  = $rows->[1]{title};

        my $author1 = $rows->[1]{author};

    }

Specify row count as argument.

You can get the following data.

    [

        {title => 'Perl', author => 'Ken'},

        {title => 'Ruby', author => 'Mark'}

    ]

=head3 Fetch all rows (hash) C<fetch_hash_all()>

use C<fetch_hash_all()> to fetch all rows and

assign it into array reference which has hash 

references as element.

    my $rows = $result->fetch_hash_all;

You can get the following data.

    [

        {title => 'Perl', author => 'Ken'},

        {title => 'Ruby', author => 'Mark'}

    ]

=head3 Statement handle C<sth()>

use <sth()> to get statement handle.

    my $sth = $result->sth;

=head2 4. Filtering

L<DBIx::Custom> provide value filtering. 

For example, You maybe want to convert L<Time::Piece> object to

database date format when register data into database.

and convert database date fromat to L<Time::Piece> object

when get data from database.

=head3 Register filter C<register_filter()>

use C<register_filter() to register filter.

    $dbi->register_filter(

        # Time::Piece object to DATE format

        tp_to_date => sub {

            my $date = shift;

            return '0000-00-00' unless $tp;

            return $tp->strftime('%Y-%m-%d');

        },

        # DATE to Time::Piece object

        date_to_tp => sub {

            my $date = shift;

            return if $date eq '0000-00-00';

            return Time::Piece->strptime($date, '%Y-%m-%d');

        },

    );

Registered filter is used by C<apply_filter()> or etc.

=head3 Apply filter C<apply_filter()>

use C<apply_filter()> to apply registered filter.

    $dbi->apply_filter('book',

        issue_date => {out => 'tp_to_date', in => 'date_to_tp'},

        first_issue_date => {out => 'tp_to_date', in => 'date_to_tp'}

    );

First argument is table name. Arguments after first argument are pairs of column

name and fitering rule. C<out> of filtering rule is filter which is used when data

is send to database. C<in> of filtering rule is filter which is used when data

is got from database. 

You can specify code reference as filter.

    issue_date => {out => sub { ... }, in => sub { ... }}

Applied filter become effective at insert()>, C<update()>, C<update_all()>,

C<delete()>, C<delete_all()>, C<select()>.

    my $tp = Time::Piece->strptime('2010/10/14', '%Y/%m/%d');

    my $result = $dbi->select(table => 'book', where => {issue_date => $tp});

When data is send to database, L<Time::Piece> object is converted

to database date format "2010-10-14"

When data is fetched, database date format is

converted to L<Time::Piece> object.

    my $row = $resutl->fetch_hash_first;

    my $tp = $row->{issue_date};

You can also use column name which contains table name.

    $dbi->select(

        table => 'book',

        where => {'book.issue_date' => $tp}

    );

In fetching, Filter is effective if you use "TABLE__COLUMN" as column name.

    my $result = $dbi->execute(

       "select issue_date as book__issue_date from book");

You can apply C<end> filter execute after C<in> filter.

    $dbi->apply_filter('book',

        issue_date => {out => 'tp_to_date', in => 'date_to_tp',

                       end => 'tp_to_displaydate'},

    );

=head3 Individual filter C<filter>

You can apply individual filter .

This filter overwrite the filter by C<apply_filter()>

use C<filter> option to apply individual filter

when data is send to database.

This option is used at C<insert()>, C<update()>,

C<update_all()>, C<delete()>, C<delete_all()>, C<select()>,

C<execute()>.

C<insert()> example:

    $dbi->insert(

        table => 'book',

        param => {issue_date => $tp, first_issue_date => $tp},

        filter => {issue_date => 'tp_to_date', first_issue_date => 'tp_to_date'}

    );

C<execute()> example:

my $sql = <<"EOS";

select YEAR(issue_date) as issue_year

from book

where YEAR(issue_date) = {? issue_year}

EOS

    my $result = $dbi->execute(

        $sql,

        param => {issue_year => '2010'},

        filter => {issue_year => 'tp_to_year'}

    );

You can also apply indivisual filter when you fetch row.

use C<DBIx::Custom::Result>'s C<filter()>.

    $result->filter(issue_year => 'year_to_tp');

=head3 End filtering : C<end_filter()>

You can add filter at end.

It is useful to create last output.

use C<end_filter()> to add end filter.

    $result->end_filter(issue_date => sub {

        my $tp = shift;

        return '' unless $tp;

        return $tp->strftime('%Y/%m/%d %h:%m:%s (%a)');

    });

In this example, L<Time::Piece> object is converted to readable format.

=head3 Automate applying filter C<each_column()>

It is useful to apply filter automatically at date type columns.

You can use C<each_column()> to process all column infos.

    $dbi->each_column(

        sub {

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

            my $type = $info->{TYPE_NAME};

            my $filter = $type eq 'DATE'     ? {out => 'tp_to_date', in => 'date_to_tp'}

                       : $type eq 'DATETIME' ? {out => 'tp_to_datetime', in => 'datetime_to_tp'}

                                             : undef;

            $self->apply_filter($table, $column, $filter)

              if $filter;

        }

    );

C<each_column() receive callback.

callback arguments are L<DBIx::Custom> object, table name, column name, column information.

Filter is applied automatically by column type.

=head2 5. Tag

=head3 Basic of Tag

You can embedd tag into SQL.

    select * from book where {= title} and {like author};

{= title} and {like author} are tag. Tag has the folloring format.

    {TAG_NAME ARG1 ARG2 ...}

Tag start C<{> and end C<}>. 

Don't insert space between C<{} and tag name.

C<{> and C<}> are reserved word.

If you want to use these, escape it by '\';

    select from book \\{ ... \\}

\ is perl's escape character, you need two \.

Tag is expanded before executing SQL.

    select * from book where title = ? and author like ?;

use C<execute()> to execute SQL which contains tag

    my $sql = "select * from book where {= author} and {like title};"

    $dbi->execute($sql, param => {title => 'Perl', author => '%Ken%'});

You can specify values embedded into place holder as hash reference using

C<param> option.

You can specify C<filter()> at C<execute()>.

    $dbi->execute($sql, param => {title => 'Perl', author => '%Ken%'}

                  filter => {title => 'to_something');

Note that at C<execute()> the filter applied by C<apply_filter()>

don't has effective to columns.

You have to use C<table> tag in SQL

    my $sql = "select * from {table book} where {= author} and {like title};"

=head3 Tag list

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The following tag is available.

=head4 C<table>

    {table NAME} -> NAME

This is used to specify table name in SQL.

If you specify table name, Filtering by 

C<apply_filter()> is effective.

=head4 C<?>

    {? NAME}    ->   ?

=head4 C<=>

    {= NAME}    ->   NAME = ?

=head4 C<E<lt>E<gt>>

    {<> NAME}   ->   NAME <> ?

=head4 C<E<lt>>

    {< NAME}    ->   NAME < ?

=head4 C<E<gt>>

    {> NAME}    ->   NAME > ?

=head4 C<E<gt>=>

    {>= NAME}   ->   NAME >= ?

=head4 C<E<lt>=>

    {<= NAME}   ->   NAME <= ?

=head4 C<like>

    {like NAME}   ->   NAME like ?

=head4 C<in>

    {in NAME COUNT}   ->   NAME in [?, ?, ..]

=head4 C<insert_param>

    {insert_param NAME1 NAME2}   ->   (NAME1, NAME2) values (?, ?)

=head4 C<update_param>

    {update_param NAME1 NAME2}   ->   set NAME1 = ?, NAME2 = ?

=head3 Manipulate same name's columns

It is ok if there are same name's columns.

Let's think two date comparison.

    my $sql = "select * from table where {> date} and {< date};";

In this case, You specify paramter values as array reference.

    my $dbi->execute($sql, param => {date => ['2010-10-01', '2012-02-10']});

=head3 Register Tag C<register_tag()>

You can register your tag.

use C<register_tag()> to register tag.

    $dbi->register_tag(

        '=' => sub {

            my $column = shift;

            return ["$column = ?", [$column]];

        }

    );

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    my $where_clause = $where->to_string;

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    where {= title}

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    my $where_clause = "$where";

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=head3 ����̗񖼂�܂ޏꍇ

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    my $param = {start_date => '2010-11-15', end_date => '2011-11-21'};

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    my $p = {date => ['2010-11-15', '2011-11-21']};

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    $where->clause(

        ['and', '{> date}', '{< date}']

    );

    $where->param($p);

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    my $p = {date => [$dbi->not_exists, '2011-11-21']};

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    my $p = {date => ['2010-11-15']};

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    my $p = {date => []};

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    my @date;

    push @date, exists $param->{start_date} ? $param->{start_date}

                                            : $dbi->not_exists;

    push @date, $param->{end_date} if exists $param->{end_date};

    my $p = {date => \@date};

=head3 C<select()>�Ƃ̘A�g

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    my $where = $dbi->where;

    $where->clause(...);

    $where->param($param);

    my $result = $dbi->select(table => 'book', where => $where);

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=head3 C<execute()>�Ƃ̘A�g

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    my $where = $dbi->where;

    $where->clause(...);

    $where->param($param);

    my $sql = <<"EOS"

    select * from book;

    $where

    EOS

    $dbi->execute($sql, param => $param);

=head2 7. Table object

=head3 Create table object C<table()>

You can create table object to access table in database.

use C<tabel()> to create table object.

    my $table = $dbi->table('book');

Return value is L<DBIx::Custom::Table>.

From table object, you can call C<insert()>, C<update()>, C<update_all()>�A

C<delete()>, C<delete_all()>, C<select()>.

You don't have to specify table name.

    $table->insert(param => $param);

You can add any method to table object.

    $table->method(

        register => sub {

            my $self = shift;

            my $table_name = $self->name;

            # ...

        },

        list => sub { ... }

    );

You can get table name by C<name()>.

You can call these method from table object.

    $table->register(...);

    $table->list(...);

=head2 Use L<DBIx::Custom> and <DBI> methods

You can call all methods of L<DBIx::Custom> and L<DBI>

    # DBIx::Custom method

    $table->execute($sql);

    # DBI method

    $table->begin_work;

    $table->commit;

=head2 Add table shared method

To share methods in all tables,

add method to base table.

You can get base table by C<base_table()>.

    $dbi->base_table->method(

        count => sub {

            my $self = shift;

            return $self->select(column => ['count(*)']);

        }

    );

This method is used by all talbes.

    $dbi->table('book')->count(...);