DOKK / manpages / debian 10 / libdbix-dr-perl / DBIx::README.3pm.en
README(3pm) User Contributed Perl Documentation README(3pm)

DBIx::DR - easy DBI helper (perl inside SQL and blessed results)

    my $dbh = DBIx::DR->connect($dsn, $login, $passed);
    $dbh->perform(
        'UPDATE tbl SET a = 1 WHERE id = <%= $id %>',
        id => 123
    );
    my $rowset = $dbh->select(
        'SELECT * FROM tbl WHERE id IN (<% list @$ids %>)',
        ids => [ 123, 456 ]
    );
    my $rowset = $dbh->select(-f => 'sqlfile.sql.ep', ids => [ 123, 456 ]);
    while(my $row = $rowset->next) {
        print "id: %d, value: %s\n", $row->id, $row->value;
    }

The package extends DBI and allows You:

  • to use perl inside Your SQL requests;
  • to bless resultsets into Your package;
  • to place Your SQL's into dedicated directory;
  • to use usual DBI methods.

A string describes iterator class. Default value is 'dbix-dr-iterator#new' (decamelized string).

A string describes item (one row) class. Default value is 'dbix-dr-iterator-item#new' (decamelized string).

Directory path to seek sql files (If You use dedicated SQLs).

Decode database errors into utf-8

Default value: "true". If true, it will open sql files with option ":utf8".

All methods can receive the following arguments:

It will load SQL-request from file. It will seek file in directory that was defined in dr_sql_dir param of connect.

You needn't to use suffixes (.sql.ep) here, but You can.

It will bless (or construct) row into specified class. See below. Default value defined by dr_item argument of DBI::connect.
Do not bless row into any class.
It will bless (or construct) rowset into specified class. Default value defined by dr_iterator argument of DBI::connect.
Do not bless rowset into any class.
Do not pass iterator as second argument to item constructor.
Additional DBI arguments.
Selects into HASH. Iterator will operate by names (not numbers).
If true the method will die with SQL-request.
If true the method will warn with SQL-request.

Are strings that represent class [ and method ].

 foo_bar                => FooBar
 foo_bar#subroutine     => FooBar->subroutine
 foo_bar-baz            => FooBar::Baz

Does SQL-request like 'UPDATE', 'INSERT', etc.

    $dbh->perform($sql, value => 1, other_value => 'abc');
    $dbh->perform(-f => $sql_file_name, value => 1, other_value => 'abc');

Does SQL-request, pack results into iterator class. By default it uses DBIx::DR::Iterator class.

    my $res = $dbh->select(-f => $sql_file_name, value => 1);
    while(my $row = $res->next) {
        printf "RowId: %d, RowValue: %s\n", $row->id, $row->value;
    }
    my $row = $row->get(15);  # row 15
    my $res = $dbh->select(-f => $sql_file_name,
            value => 1, -hash => 'name');
    while(my $row = $res->next) {
        printf "RowId: %d, RowName: %s\n", $row->id, $row->name;
    }
    my $row = $row->get('Vasya');  # row with name eq 'Vasya'

Does SQL-request that returns one row. Pack results into item class. Does SQL-request, pack results (one row) into item class. By default it uses DBIx::DR::Iterator::Item class.

You can use perl inside Your SQL requests:

    % my $foo = 1;
    % my $bar = 2;
    <% my $foo_bar = $foo + $bar %>
    ..
    % use POSIX;
    % my $gid = POSIX::getgid;

There are two functions available inside perl:

Replaces argument to '?', add argument value into bindlist. You can also use shortcut '=' instead of the function.

Example 1

    SELECT
        *
    FROM
        tbl
    WHERE
        id = <% quote $id %>

Result

    SELECT
        *
    FROM
        tbl
    WHERE
        id = ?

and bindlist will contain id value.

If You use DBIx::DR::ByteStream in place of string the function will recall immediate function.

Example 2

    SELECT
        *
    FROM
        tbl
    WHERE
        id = <%= $id %>

Replaces argument to its value. You can also use shortcut '==' instead of the function.

Example 1

    SELECT
        *
    FROM
        tbl
    WHERE
        id = <% immediate $id %>

Result

    SELECT
        *
    FROM
        tbl
    WHERE
        id = 123

Where 123 is id value.

Be carful! Using the operator You can produce code that will be amenable to SQL-injection.

Example 2

    SELECT
        *
    FROM
        tbl
    WHERE
        id = <%== $id %>

There are a few default helpers.

Expands array into Your SQL request.

Example

    SELECT
        *
    FROM
        tbl
    WHERE
        status IN (<% list @$ids %>)

Result

    SELECT
        *
    FROM
        tbl
    WHERE
        status IN (?,?,? ...)

and bindlist will contain ids values.

Expands array of hash into Your SQL request. The first argument can be a list of required keys. Places each group into brackets.

Example

    INSERT INTO
        tbl
            ('a', 'b')
    VALUES
        <% hlist ['a', 'b'] => @$inserts

Result

    INSERT INTO
        tbl
            ('a', 'b')
    VALUES
        (?, ?), (?, ?) ...

and bindlist will contain all inserts values.

Includes the other SQL-part.

Example

    % include 'other_sql', argument1 => 1, argument2 => 2;

Returns perl stacktrace. You can use the helper for debug Your code. The helper receives the following position-arguments:

(first) $skip (default = 0)
How many frames to skip.
(second) $dept (default = 0)
How many frames to print.
(third) $separator (default ", ")
Separator between stackframes.

Examples

    /* <%= stacktrace %> */
    /* <%= stacktrace $skip, $depth, $separator %> */

You can add Your helpers using method set_helper.

Sets (or replaces) helpers.

    $dbh->set_helper(foo => sub { ... }, bar => sub { ... });

Each helper receives template object as the first argument.

Examples:

    $dbh->set_helper(foo_AxB => sub {
        my ($tpl, $a, $b) = @_;
        $tpl->quote($a * $b);
    });

You can use quote and immediate functions inside Your helpers.

If You want use the other helper inside Your helper You have to do that by Yourself. To call the other helper You can also use "$tpl->call_helper" function.

call_helper

    $dbh->set_helper(
        foo => sub {
            my ($tpl, $a, $b) = @_;
            $tpl->quote('foo' . $a . $b);
        },
        bar => sub {
            my $tpl = shift;
            $tpl->call_helper(foo => 'b', 'c');
        }
    );

 Copyright (C) 2011 Dmitry E. Oboukhov <unera@debian.org>
 Copyright (C) 2011 Roman V. Nikolaev <rshadow@rambler.ru>
 This program is free software, you can redistribute it and/or
 modify it under the terms of the Artistic License.

The project is placed git repo on github: <https://github.com/unera/dbix-dr/>

2017-04-18 perl v5.24.1