NAME

Query::Abstract - Create filters in Perlish way and transforms them into coderefs or SQL

SYNOPSIS

# Pure Perl filtering
my $qa = Query::Abstract->new( driver => ['ArrayOfHashes'] );

my $query_sub = $qa->convert_query(
    where => [ 
        name => 'John', 
        age => { '>' => 25 }, 
        last_name => { like => 'ing' } 
    ],
    sort_by => 'last_name DESC, login ASC'
);

$filtered_and_sorted_users = $query_sub->(\@users);

# Preparing SQL statement
my $qa = Query::Abstract->new( driver => ['SQL' => [table => 'users']] );

## The same but explicilty creating driver object.
my $qa = Query::Abstract->new( driver => Query::Abstract::Driver::SQL->new(table => 'users') );

my $sql_statement = $qa->convert_query(
    where => [ 
        name => 'John', 
        age => { '>' => 25 }, 
        last_name => { like => 'ing' } 
    ],
    sort_by => 'last_name DESC, login ASC'
);
  

WARNING

This software is under the heavy development and considered ALPHA quality. 
Things might be broken, not all features have been implemented, and APIs will be likely to change. 
YOU HAVE BEEN WARNED.

DESCRIPTION

Query::Abstract - allows you to write queries and then tranform them into another format(depends in driver). Queries are almost compatible with Rose::DB::Object queries. This module apperared because I wanted to have pure Perl queries but with ability to convert them into SQL(or other format).

Currently this module has two standard drivers - ArrayOfHashes and SQL.(You can write your own)

METHODS

convert_filter

$self->convert_filter([ name => 'John', age => { '>' => 25 }, last_name => { like => 'ing' } ]);

"SQL" Driver will return 'WHERE' clause and bind values.

"ArrayOfHashes" will return a coderef which takes hashref and returns true or false depending on condition testing result.

my $tester = $self->convert_filter([ name => 'John', age => { '>' => 25 }, last_name => { like => 'ing' } ]);
@filtered = grep { $tester->($_) } ( {name => 'Anton', age => 37, last_name => 'Corning'}, {name => 'John'} ... )

convert_sort

$self->convert_sort('name DESC, age ASC, last_name DESC');

"SQL" Driver will return 'ORDER BY' clause.

"ArrayOfHashes" will return a coderef for "sort" function

my $sort_sub = $self->convert_sort(...);
@sorted = sort $sort_sub @data;

convert_query

$self->convert_query( where => [name => 'John'], sort_by => 'last_name DESC' );

"SQL" Driver will return 'SELECT' with 'WHERE' and 'ORDER BY' conditions.

"ArrayOfHashes" will return a coderef for quering data

my $query_sub = $self->convert_query(...);
$filtered_and_sorted = $query_sub->( \@data );

AUTHOR

Viktor Turskyi <koorchik@cpan.org>

BUGS

Please report any bugs or feature requests to Github https://github.com/koorchik/Query-Abstract

SEE ALSO

Rose::DB::Object::QueryBuilder, SQL::Abstract, SQL::Maker