/ 
DBIx-DoMore-0.01001
River stage zero No dependents
/ DBIx::DoMore

NAME

DBIx::DoMore - Multiple SQL statements in a single do() call with any DBI driver

VERSION

Version 0.01000

SYNOPSIS

use DBI;
use DBIx::DoMore;

my $create = <<'SQL';
CREATE TABLE parent(a, b, c   , d    );
CREATE TABLE child (x, y, "w;", "z;z");
CREATE TRIGGER "check;delete;parent;" BEFORE DELETE ON parent WHEN
    EXISTS (SELECT 1 FROM child WHERE old.a = x AND old.b = y)
BEGIN
    SELECT RAISE(ABORT, 'constraint failed;');
END;
INSERT INTO parent (a, b, c, d) VALUES ('pippo;', 'pluto;', NULL, NULL)
SQL

my $dbh = DBI->connect( 'dbi:SQLite:dbname=my.db', '', '' );

my $do_more = DBIx::DoMore->new( dbh => $dbh );

# Multiple SQL statements in a single call
my @results = $do_more->do( $create );

print scalar(@results) . ' statements successfully executed!';
# 4 statements successfully executed!

DESCRIPTION

Some DBI drivers don't support the execution of multiple statements in a single do() call. This module tries to overcome such limitation, letting you execute any number of SQL statements (of any kind, not only DDL statements) in a single batch, with any DBI driver.

Here is how DBIx::DoMore works: behind the scenes it parses the SQL code, splits it into the atomic statements it is composed of and executes them one by one. The logic used to split the SQL code is more sophisticated than a naive blind split on the ; (semicolon) character, so that DBIx::DoMore is able to correctly handle the presence of the semicolon inside identifiers, values or BEGIN..END blocks, as shown in the synopsis above.

Automatic transactions support is offered by default, so that you'll have the all-or-nothing behaviour you would probably expect; if you prefer, you can anyway disable it and manage the transactions yourself.

METHODS

new

  • DBIx::DoMore->new( %options )

  • DBIx::DoMore->new( \%options )

It creates and returns a new DBIx::DoMore object. It accepts its options either as an hash or an hashref.

The following options are recognized:

  • dbh

    The database handle object as returned by DBI::connect(). This option is required.

  • rollback

    A boolean option which enables (when true) or disables (when false) automatic transactions. It is set to a true value by default.

do

  • $do_more->do( $sql_string )

This is the method which actually executes the SQL statements against your db. It takes a string containing one or more SQL statements and executes them one by one, in the same order they appear in the given SQL string.

In list context, it returns a list containing the values returned by the DBI do call on each single atomic statement.

If the rollback option has been set (and therefore automatic transactions are enabled), in case one of the atomic statements fails, all of the other succeeding statements executed so far, if any exists, are rolled back and the method (immediately) returns an empty list (since no statement has been actually committed).

If the rollback option is set to a false value (and therefore automatic transactions are disabled), the method immediately returns at the first failing statement as above, but it does not roll back any prior succeeding statement, and therefore a list containing the values returned by the statement executed so far is returned (and these statements are actually committed to the db, if $dbh->{AutoCommit} is set).

In scalar context it returns, regardless of the value of the rollback option, undef if any of the atomic statements fails, or a true value if all of the atomic statements succeed.

Note that to activate the automatic transactions you don't have to do anything other than setting the rollback option to a true value (or simply do nothing, as it is the default): DBIx::DoMore will automatically (and temporarily, via local) set $dbh->{AutoCommit} and $dbh->{RaiseError} as needed. No other database handle attribute is touched, so that you can for example set $dbh->{PrintError} and enjoy its effect in case of a failing statement.

If you want to disable automatic transactions and manage them by yourself, you can do something along this:

my $do_more = DBIx::DoMore->new(
    dbh      => $dbh,
    rollback => 0
);

my @results;

$do_more->dbh->{AutoCommit} = 0;
$do_more->dbh->{RaiseError} = 1;
eval {
    @results = $do_more->do( $sql_string );
    $do_more->dbh->commit;
    1
} or eval { $do_more->dbh->rollback };

dbh

  • $do_more->dbh

  • $do_more->dbh( $new_dbh )

    Getter/setter method for the dbh option explained above.

rollback

  • $do_more->rollback

  • $do_more->rollback( $boolean )

    Getter/setter method for the rollback option explained above.

split

  • DBIx::DoMore->split( $sql_string )

This is the method used internally to split the given SQL string into its atomic statements.

It returns a list of strings containing the code of each atomic statement, in the same order they appear in the given SQL string.

You shouldn't care about it, unless you want to bypass all the other functionality offered by this module and do it by yourself, in which case you can use it as a class method, like this:

$dbh->do($_) foreach DBIx::DoMore->split( $sql_string );

DEPENDENCIES

DBIx::DoMore depends on the following modules:

AUTHOR

Emanuele Zeppieri, <emazep@cpan.org>

BUGS

Please report any bugs or feature requests to bug-dbix-domore at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=DBIx-DoMore. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

perldoc DBIx::DoMore

You can also look for information at:

ACKNOWLEDGEMENTS

Igor Sutton for his excellent SQL::Tokenizer, which made writing this module a joke.

SEE ALSO

LICENSE AND COPYRIGHT

Copyright 2010 Emanuele Zeppieri.

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation, or the Artistic License.

See http://dev.perl.org/licenses/ for more information.