NAME

DBIx::Custom - DBI interface, having hash parameter binding and filtering system

SYNOPSYS

Connect to the database.

use DBIx::Custom;
my $dbi = DBIx::Custom->connect(data_source => "dbi:mysql:database=dbname",
                                user => 'ken', password => '!LFKD%$&');

Insert, update, and delete

# Insert 
$dbi->insert(table  => 'books',
             param  => {title => 'Perl', author => 'Ken'},
             filter => {title => 'encode_utf8'});

# Update 
$dbi->update(table  => 'books', 
             param  => {title => 'Perl', author => 'Ken'}, 
             where  => {id => 5},
             filter => {title => 'encode_utf8'});

# Update all
$dbi->update_all(table  => 'books',
                 param  => {title => 'Perl'},
                 filter => {title => 'encode_utf8'});

# Delete
$dbi->delete(table  => 'books',
             where  => {author => 'Ken'},
             filter => {title => 'encode_utf8'});

# Delete all
$dbi->delete_all(table => 'books');

Select

# Select
my $result = $dbi->select(table => 'books');

# Select, more complex
my $result = $dbi->select(
    table  => 'books',
    column => [qw/author title/],
    where  => {author => 'Ken'},
    append => 'order by id limit 5',
    filter => {title => 'encode_utf8'}
);

# Select, join table
my $result = $dbi->select(
    table    => ['books', 'rental'],
    column   => ['books.name as book_name']
    relation => {'books.id' => 'rental.book_id'}
);

# Select, more flexible where
my $result = $dbi->select(
    table  => 'books',
    where  => ['{= author} and {like title}', 
               {author => 'Ken', title => '%Perl%'}]
);

Execute SQL

# Execute SQL
$dbi->execute("select title from books");

# Execute SQL with hash binding and filtering
$dbi->execute("select id from books where {= author} and {like title}",
              param  => {author => 'ken', title => '%Perl%'},
              filter => {title => 'encode_utf8'});

# Create query and execute it
my $query = $dbi->create_query(
    "select id from books where {= author} and {like title}"
);
$dbi->execute($query, param => {author => 'Ken', title => '%Perl%'})

Other features.

# Default filter
$dbi->default_bind_filter('encode_utf8');
$dbi->default_fetch_filter('decode_utf8');

# Get DBI object
my $dbh = $dbi->dbh;

Fetch row.

# Fetch
while (my $row = $result->fetch) {
    # ...
}

# Fetch hash
while (my $row = $result->fetch_hash) {
    
}

DESCRIPTIONS

1. Features

DBIx::Custom is one of DBI interface modules, such as DBIx::Class, DBIx::Simple.

This module is not O/R mapper. O/R mapper is useful, but you must learn many syntax of the O/R mapper, which is almost another language. Created SQL statement is offten not effcient and damage SQL performance. so you have to execute raw SQL in the end.

DBIx::Custom is middle area between DBI and O/R mapper. DBIx::Custom provide flexible hash parameter binding and filtering system, and suger methods, such as select(), update(), delete(), select() to execute SQL easily.

DBIx::Custom respects SQL. SQL is very complex and not beautiful, but de-facto standard, so all people learing database know it. If you already know SQL, you learn a little thing to use DBIx::Custom.

2. Connect to the database

connect() method create a new DBIx::Custom object and connect to the database.

use DBIx::Custom;
my $dbi = DBIx::Custom->connect(data_source => "dbi:mysql:database=dbname",
                                user => 'ken', password => '!LFKD%$&');

If database is SQLite, use DBIx::Custom::SQLite instead. you connect database easily.

use DBIx::Custom::SQLite;
my $dbi = DBIx::Custom::SQLite->connect(database => 'dbname');

If database is MySQL, use DBIx::Custom::MySQL.

use DBIx::Custom::MySQL;
my $dbi = DBIx::Custom::MySQL->connect(
    database => 'dbname',
    user     => 'ken',
    password => '!LFKD%$&'
);

3. Suger methods

DBIx::Custom has suger methods, such as insert(), update(), delete() or select(). If you want to do small works, You don't have to create SQL statements.

insert()

Execute insert statement.

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

The following SQL is executed.

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

The values of title and author is embedded into the placeholders.

append and filter argument can be specified. See also "METHODS" section.

update()

Execute update statement.

$dbi->update(table  => 'books', 
             param  => {title => 'Perl', author => 'Ken'}, 
             where  => {id => 5});

The following SQL is executed.

update books set title = ?, author = ?;

The values of title and author is embedded into the placeholders.

append and filter argument can be specified. See also "METHOD" section.

If you want to update all rows, use update_all() method.

delete()

Execute delete statement.

$dbi->delete(table  => 'books',
             where  => {author => 'Ken'});

The following SQL is executed.

delete from books where id = ?;

The value of id is embedded into the placehodler.

append and filter argument can be specified. see also "METHODS" section.

If you want to delete all rows, use delete_all() method.

select()

Execute select statement, only table argument specified :

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

The following SQL is executed.

select * from books;

the result of select() method is DBIx::Custom::Result object. You can fetch a row by fetch() method.

while (my $row = $result->fetch) {
    my $title  = $row->[0];
    my $author = $row->[1];
}

DBIx::Custom::Result has various methods to fetch row. See "4. Fetch row".

column and where arguments specified.

my $result = $dbi->select(
    table  => 'books',
    column => [qw/author title/],
    where  => {author => 'Ken'}
);

The following SQL is executed.

select author, title from books where author = ?;

the value of author is embdded into the placeholder.

If you want to join tables, specify relation argument.

my $result = $dbi->select(
    table    => ['books', 'rental'],
    column   => ['books.name as book_name']
    relation => {'books.id' => 'rental.book_id'}
);

The following SQL is executed.

select books.name as book_name from books, rental
where books.id = rental.book_id;

If you want to add some string to the end of SQL statement, use append argument.

my $result = $dbi->select(
    table  => 'books',
    where  => {author => 'Ken'},
    append => 'order by price limit 5',
);

The following SQL is executed.

select * books where author = ? order by price limit 5;

filter argument can be specified. see also "METHODS" section.

4. Fetch row

select() method return DBIx::Custom::Result object. You can fetch row by various methods. Note that in this section, array means array reference, and hash meanse hash reference.

Fetch row into array.

while (my $row = $result->fetch) {
    my $author = $row->[0];
    my $title  = $row->[1];
    
}

Fetch only a first row into array.

my $row = $result->fetch_first;

Fetch multiple rows into array of array.

while (my $rows = $result->fetch_multi(5)) {
    my $first_author  = $rows->[0][0];
    my $first_title   = $rows->[0][1];
    my $second_author = $rows->[1][0];
    my $second_value  = $rows->[1][1];

}

Fetch all rows into array of array.

my $rows = $result->fetch_all;

Fetch row into hash.

# Fetch a row into hash
while (my $row = $result->fetch_hash) {
    my $title  = $row->{title};
    my $author = $row->{author};
    
}

Fetch only a first row into hash

my $row = $result->fetch_hash_first;

Fetch multiple rows into array of hash

while (my $rows = $result->fetch_hash_multi(5)) {
    my $first_title   = $rows->[0]{title};
    my $first_author  = $rows->[0]{author};
    my $second_title  = $rows->[1]{title};
    my $second_author = $rows->[1]{author};

}

Fetch all rows into array of hash

my $rows = $result->fetch_hash_all;

If you want to access statement handle of DBI, use sth attribute.

my $sth = $result->sth;

5. Hash parameter binding

DBIx::Custom provides hash parameter binding.

At frist, I show normal parameter binding.

use DBI;
my $dbh = DBI->connect(...);
my $sth = $dbh->prepare(
    "select * from books where author = ? and title like ?;"
);
$sth->execute('Ken', '%Perl%');

This is very good way because database system can enable SQL caching, and parameter is quoted automatically. this is secure.

DBIx::Custom hash parameter binding system improve normal parameter binding to use hash parameter.

my $result = $dbi->execute(
    "select * from books where {= author} and {like title};"
    param => {author => 'Ken', title => '%Perl%'}
);

This is same as the normal way, execpt that the parameter is hash. {= author} and {like title} is called tag. tag is expand to placeholder string internally.

select * from books where {= author} and {like title}
  -> select * from books where author = ? and title like ?;

The following tags is available.

[TAG]                       [REPLACED]
{? NAME}               ->   ?
{= NAME}               ->   NAME = ?
{<> NAME}              ->   NAME <> ?

{< NAME}               ->   NAME < ?
{> NAME}               ->   NAME > ?
{>= NAME}              ->   NAME >= ?
{<= NAME}              ->   NAME <= ?

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

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

See also DBIx::Custom::QueryBuilder.

{ and } is reserved. If you use these charactors, you must escape them using '\'. Note that '\' is already perl escaped charactor, so you must write '\\'.

'select * from books \\{ something statement \\}'

6. Filtering

Usually, Perl string is kept as internal string. If you want to save the string to database, You must encode the string. Filtering system help you to convert a data to another data when you save to the data and get the data form database.

If you want to register filter, use register_filter() method.

$dbi->register_filter(
    to_upper_case => sub {
        my $value = shift;
        return uc $value;
    }
);

encode_utf8 and decode_utf8 filter is registerd by default.

You can specify these filters to filter argument of execute() method.

my $result = $dbi->execute(
    "select * from books where {= author} and {like title};"
    param  => {author => 'Ken', title => '%Perl%'},
    filter => {author => 'to_upper_case, title => 'encode_utf8'}
);

filter argument can be specified to suger methods, such as insert(), update(), update_all(), delete(), delete_all(), select().

# insert(), having filter argument
$dbi->insert(table  => 'books',
             param  => {title => 'Perl', author => 'Ken'},
             filter => {title => 'encode_utf8'});

# select(), having filter argument
my $result = $dbi->select(
    table  => 'books',
    column => [qw/author title/],
    where  => {author => 'Ken'},
    append => 'order by id limit 1',
    filter => {title => 'encode_utf8'}
);

Filter works each parmeter, but you prepare default filter for all parameters.

$dbi->default_bind_filter('encode_utf8');

filter() argument overwrites this default filter.

$dbi->default_bind_filter('encode_utf8');
$dbi->insert(
    table  => 'books',
    param  => {title => 'Perl', author => 'Ken', price => 1000},
    filter => {author => 'to_upper_case', price => undef}
);

This is same as the following example.

$dbi->insert(
    table  => 'books',
    param  => {title => 'Perl', author => 'Ken', price => 1000},
    filter => {title => 'encode_uft8' author => 'to_upper_case'}
);

You can also specify filter when the row is fetched. This is reverse of bind filter.

my $result = $dbi->select(table => 'books');
$result->filter({title => 'decode_utf8', author => 'to_upper_case'});

Filter works each column value, but you prepare a default filter for all clumn value.

$dbi->default_fetch_filter('decode_utf8');

filter() method of DBIx::Custom::Result overwrites this default filter.

$dbi->default_fetch_filter('decode_utf8');
my $result = $dbi->select(
    table => 'books',
    columns => ['title', 'author', 'price']
);
$result->filter({author => 'to_upper_case', price => undef});

This is same as the following one.

my $result = $dbi->select(
    table => 'books',
    columns => ['title', 'author', 'price']
);
$result->filter({title => 'decode_utf8', author => 'to_upper_case'});

Note that in fetch filter, column names must be lower case even if the column name conatains upper case charactors. This is requirment not to depend database systems.

7. Get high performance

Disable filter checking

Filter checking is executed by default. This is done to check right filter name is specified, but sometimes damage performance.

If you disable this filter checking, Set filter_check attribute to 0.

$dbi->filter_check(0);

Use execute() method instead suger methods

If you execute insert statement by insert() method, you sometimes can't get required performance.

insert() method is a little slow because SQL statement and statement handle is created every time.

In that case, you can prepare a query by create_query() method.

my $query = $dbi->create_query(
    "insert into books {insert_param title author};"
);

Return value of create_query() is DBIx::Custom::Query object. This keep the information of SQL and column names.

{
    sql     => 'insert into books (title, author) values (?, ?);',
    columns => ['title', 'author']
}

Execute query repeatedly.

my $inputs = [
    {title => 'Perl',      author => 'Ken'},
    {title => 'Good days', author => 'Mike'}
];

foreach my $input (@$inputs) {
    $dbi->execute($query, $input);
}

This is faster than insert() method.

caching

execute() method caches the parsed result of the source of SQL. Default to 1

$dbi->cache(1);

Caching is on memory, but you can change this by cache_method(). First argument is DBIx::Custom object. Second argument is a source of SQL, such as "select * from books where {= title} and {= author};"; Third argument is parsed result, such as {sql => "select * from books where title = ? and author = ?", columns => ['title', 'author']}, this is hash reference. If arguments is more than two, this method is called to set cache. If not, this method is called to get cache.

$dbi->cache_method(sub {
    sub {
        my $self = shift;
        
        $self->{_cached} ||= {};
        
        # Set cache
        if (@_ > 1) {
            $self->{_cached}{$_[0]} = $_[1] 
        }
        
        # Get cache
        else {
            return $self->{_cached}{$_[0]}
        }
    }
});

8. More features

Get DBI object

You can get DBI object and call any method of DBI.

$dbi->dbh->begin_work;
$dbi->dbh->commit;
$dbi->dbh->rollback;

Change Result class

You can change Result class if you need.

package Your::Result;
use base 'DBIx::Custom::Result';

sub some_method { ... }

1;

package main;

use Your::Result;

my $dbi = DBIx::Custom->connect(...);
$dbi->result_class('Your::Result');

Custamize SQL builder object

You can custamize SQL builder object

my $dbi = DBIx::Custom->connect(...);
$dbi->query_builder->register_tag_processor(
    name => sub {
       ...
    }
);

ATTRIBUTES

user

my $user = $dbi->user;
$dbi     = $dbi->user('Ken');

User name. connect() method use this value to connect the database.

password

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

Password. connect() method use this value to connect the database.

data_source

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

Data source. connect() method use this value to connect the database.

dbh

my $dbh = $dbi->dbh;
$dbi    = $dbi->dbh($dbh);

DBI object. You can call all methods of DBI.

filters

my $filters = $dbi->filters;
$dbi        = $dbi->filters(\%filters);

Filter functions. "encode_utf8" and "decode_utf8" is registered by default.

default_bind_filter

my $default_bind_filter = $dbi->default_bind_filter
$dbi                    = $dbi->default_bind_filter('encode_utf8');

Default filter when parameter binding is executed.

default_fetch_filter

my $default_fetch_filter = $dbi->default_fetch_filter;
$dbi                     = $dbi->default_fetch_filter('decode_utf8');

Default filter when row is fetched.

result_class

my $result_class = $dbi->result_class;
$dbi             = $dbi->result_class('DBIx::Custom::Result');

Result class for select statement. Default to DBIx::Custom::Result.

query_builder

my $sql_class = $dbi->query_builder;
$dbi          = $dbi->query_builder(DBIx::Custom::QueryBuilder->new);

SQL builder. query_builder() must be the instance of DBIx::Custom::QueryBuilder subclass. Default to DBIx::Custom::QueryBuilder object.

cache

my $cache = $dbi->cache;
$dbi      = $dbi->cache(1);

Enable parsed DBIx::Custom::Query object caching. Default to 1.

cache_method

$dbi          = $dbi->cache_method(\&cache_method);
$cache_method = $dbi->cache_method

Method to set and get caches.

Example:

$dbi->cache_method(
    sub {
        my $self = shift;
        
        $self->{_cached} ||= {};
        
        if (@_ > 1) {
            $self->{_cached}{$_[0]} = $_[1] 
        }
        else {
            return $self->{_cached}{$_[0]}
        }
    }
);

filter_check

my $filter_check = $dbi->filter_check;
$dbi             = $dbi->filter_check(0);

Enable filter check. Default to 1. This check maybe damege performance. If you require performance, set filter_check attribute to 0.

METHODS

DBIx::Custom inherits all methods from Object::Simple and implements the following new ones.

connect

my $dbi = DBIx::Custom->connect(data_source => "dbi:mysql:database=dbname",
                                user => 'ken', password => '!LFKD%$&');

Create a new DBIx::Custom object and connect to the database. DBIx::Custom is a wrapper of DBI. AutoCommit and RaiseError options are true, and PrintError option is false by default.

insert

$dbi->insert(table  => $table, 
             param  => \%param,
             append => $append,
             filter => \%filter);

Execute insert statement. insert method have table, param, append and filter arguments. table is a table name. param is the pairs of column name value. this must be hash reference. append is a string added at the end of the SQL statement. filter is filters when parameter binding is executed. This is overwrites default_bind_filter. Return value of insert() is the count of affected rows.

Example:

$dbi->insert(table  => 'books', 
             param  => {title => 'Perl', author => 'Taro'},
             append => "some statement",
             filter => {title => 'encode_utf8'})

update

$dbi->update(table  => $table, 
             param  => \%params,
             where  => \%where,
             append => $append,
             filter => \%filter)

Execute update statement. update method have table, param, where, append and filter arguments. table is a table name. param is column-value pairs. this must be hash reference. where is where clause. this must be hash reference. append is a string added at the end of the SQL statement. filter is filters when parameter binding is executed. This is overwrites default_bind_filter. Return value of update() is the count of affected rows.

Example:

$dbi->update(table  => 'books',
             param  => {title => 'Perl', author => 'Taro'},
             where  => {id => 5},
             append => "some statement",
             filter => {title => 'encode_utf8'});

update_all

$dbi->update_all(table  => $table, 
                 param  => \%params,
                 filter => \%filter,
                 append => $append);

Execute update statement to update all rows. Arguments is same as update method, except that update_all don't have where argument. Return value of update_all() is the count of affected rows.

Example:

$dbi->update_all(table  => 'books', 
                 param  => {author => 'taro'},
                 filter => {author => 'encode_utf8'});

delete

$dbi->delete(table  => $table,
             where  => \%where,
             append => $append,
             filter => \%filter);

Execute delete statement. delete method have table, where, append, and filter arguments. table is a table name. where is where clause. this must be hash reference. append is a string added at the end of the SQL statement. filter is filters when parameter binding is executed. Return value of delete() is the count of affected rows.

Example:

$dbi->delete(table  => 'books',
             where  => {id => 5},
             append => 'some statement',
             filter => {id => 'encode_utf8'});

delete_all

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

Execute delete statement to delete all rows. Arguments is same as delete method, except that delete_all don't have where argument. Return value of delete_all() is the count of affected rows.

Example:

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

select

my $result = $dbi->select(table    => $table,
                          column   => [@column],
                          where    => \%where,
                          append   => $append,
                          relation => \%relation,
                          filter   => \%filter);

Execute select statement. select method have table, column, where, append, relation and filter arguments. table is a table name. where is where clause. this is normally hash reference. append is a string added at the end of the SQL statement. filter is filters when parameter binding is executed.

Example:

# select * from books;
my $result = $dbi->select(table => 'books');

# select * from books where title = ?;
my $result = $dbi->select(table => 'books', where => {title => 'Perl'});

# select title, author from books where id = ? for update;
my $result = $dbi->select(
    table  => 'books',
    column => ['title', 'author'],
    where  => {id => 1},
    appned => 'for update'
);

# select books.name as book_name from books, rental
# where books.id = rental.book_id;
my $result = $dbi->select(
    table    => ['books', 'rental'],
    column   => ['books.name as book_name']
    relation => {'books.id' => 'rental.book_id'}
);

If you use more complex condition, you can specify a array reference to where argument.

my $result = $dbi->select(
    table  => 'books',
    column => ['title', 'author'],
    where  => ['{= title} or {like author}',
               {title => '%Perl%', author => 'Ken'}]
);

First element is a string. it contains tags, such as "{= title} or {like author}". Second element is paramters.

create_query

my $query = $dbi->create_query(
    "select * from books where {= author} and {like title};"
);

Create the instance of DBIx::Custom::Query from the source of SQL. If you want to get high performance, use create_query() method and execute it by execute() method instead of suger methods.

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

execute

my $result = $dbi->execute($query,  param => $params, filter => \%filter);
my $result = $dbi->execute($source, param => $params, filter => \%filter);

Execute query or the source of SQL. Query is DBIx::Custom::Query object. Return value is DBIx::Custom::Result if select statement is executed, or the count of affected rows if insert, update, delete statement is executed.

Example:

my $result = $dbi->execute(
    "select * from books where {= author} and {like title}", 
    param => {author => 'Ken', title => '%Perl%'}
);

while (my $row = $result->fetch) {
    my $author = $row->[0];
    my $title  = $row->[1];
}

register_filter

$dbi->register_filter(%filters);
$dbi->register_filter(\%filters);

Register filter. Registered filters is available in the following attributes or arguments.

  • default_bind_filter, default_fetch_filter

  • filter argument of insert(), update(), update_all(), delete(), delete_all(), select() methods

  • execute() method

  • default_filter and filter of DBIx::Custom::Query

  • default_filter and filter of DBIx::Custom::Result

Example:

$dbi->register_filter(
    encode_utf8 => sub {
        my $value = shift;
        
        require Encode;
        
        return Encode::encode('UTF-8', $value);
    },
    decode_utf8 => sub {
        my $value = shift;
        
        require Encode;
        
        return Encode::decode('UTF-8', $value)
    }
);

BUGS

Please tell me bugs if found.

<kimoto.yuki at gmail.com>

http://github.com/yuki-kimoto/DBIx-Custom

AUTHOR

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

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.