NAME

DBIx::FlexibleBinding - Greater statement placeholder and data-binding flexibility.

VERSION

version 2.0.4

SYNOPSIS

This module extends the DBI allowing you choose from a variety of supported parameter placeholder and binding patterns as well as offering simplified ways to interact with datasources, while improving general readability.

    #########################################################
    # SCENARIO 1                                            #
    # A connect followed by a prepare-execute-process cycle #
    #########################################################

    use DBIx::FlexibleBinding;
    use constant DSN => 'dbi:mysql:test;host=127.0.0.1';
    use constant SQL => << '//';
    SELECT solarSystemName AS name
      FROM mapsolarsystems
     WHERE regional  = :is_regional
       AND security >= :minimum_security
    //

    # Pretty standard connect, just with the new DBI subclass ...
    #
    my $dbh = DBIx::FlexibleBinding->connect(DSN, '', '', { RaiseError => 1 });

    # Prepare statement using named placeholders (not bad for MySQL, eh) ...
    #
    my $sth = $dbh->prepare(SQL);

    # Execute the statement (parameter binding is automatic) ...
    #
    my $rv = $sth->execute(is_regional => 1,
                           minimum_security => 1.0);

    # Fetch and transform rows with a blocking callback to get only the data you
    # want without cluttering the place up with intermediate state ...
    #
    my @system_names = $sth->getrows_hashref(callback { $_->{name} });

    ############################################################################
    # SCENARIO 2                                                               #
    # Let's simplify the previous scenario using the database handle's version #
    # of that getrows_hashref method.                                       #
    ############################################################################

    use DBIx::FlexibleBinding -alias => 'DFB';
    use constant DSN => 'dbi:mysql:test;host=127.0.0.1';
    use constant SQL => << '//';
    SELECT solarSystemName AS name
      FROM mapsolarsystems
     WHERE regional  = :is_regional
       AND security >= :minimum_security
    //

    # Pretty standard connect, this time with the DBI subclass package alias ...
    #
    my $dbh = DFB->connect(DSN, '', '', { RaiseError => 1 });

    # Cut out the middle men ...
    #
    my @system_names = $dbh->getrows_hashref(SQL,
                                             is_regional => 1,
                                             minimum_security => 1.0,
                                             callback { $_->{name} });

    #############################################################################
    # SCENARIO 3                                                                #
    # The subclass import method provides a versatile mechanism for simplifying #
    # matters further.                                                          #
    #############################################################################

    use DBIx::FlexibleBinding -subs => [ 'MyDB' ];
    use constant DSN => 'dbi:mysql:test;host=127.0.0.1';
    use constant SQL => << '//';
    SELECT solarSystemName AS name
      FROM mapsolarsystems
     WHERE regional  = :is_regional
       AND security >= :minimum_security
    //

    # MyDB will represent our datasource; initialise it ...
    #
    MyDB DSN, '', '', { RaiseError => 1 };

    # Cut out the middle men and some of the line-noise, too ...
    #
    my @system_names = MyDB(SQL,
                            is_regional => 1,
                            minimum_security => 1.0,
                            callback { $_->{name} });

DESCRIPTION

This module subclasses the DBI to provide improvements and greater flexibility in the following areas:

  • Parameter placeholders and data binding

  • Data retrieval and processing

  • Accessing and interacting with datasources

It may be most useful in situations that require a lot of database code to be written quickly.

Parameter placeholders and data binding

This module provides support for a wider range of parameter placeholder and data-binding schemes. As well as continued support for the simple positional placeholders (?), additional support is provided for numeric placeholders (:N and ?N), and named placeholders (:NAME and @NAME).

As for the process of binding data values to parameters: that is, by default, now completely automated, removing a significant part of the workload from the prepare-bind-execute cycle. It is, however, possible to swtch off automatic data-binding globally and on a statement-by-statement basis.

The following familiar operations have been modified to accommodate all of these changes, though developers continue to use them as they always have done:

  • $DATABASE_HANDLE->prepare($STATEMENT, \%ATTR);

  • $DATABASE_HANDLE->do($STATEMENT, \%ATTR, @DATA);

  • $STATEMENT_HANDLE->bind_param($NAME_OR_POSITION, $VALUE, \%ATTR);

  • $STATEMENT_HANDLE->execute(@DATA);

Data retrieval and processing

Four new methods, each available for database and statement handles, have been implemented:

  • getrow_arrayref

  • getrow_hashref

  • getrows_arrayref

  • getrows_hashref

These methods complement DBI's existing fetch methods, providing new ways to retrieve and process data.

Accessing and interacting with datasources

The module's -subs import option may be used to create subroutines, during the compile phase, and export them to the caller's namespace for use later as representations of database and statement handles.

  • Use for connecting to datasources

        use DBIx::FlexibleBinding -subs => [ 'MyDB' ];
    
        # Pass in any set of well-formed DBI->connect(...) arguments to associate
        # your name with a live database connection ...
        #
        MyDB( 'dbi:mysql:test;host=127.0.0.1', '', '', { RaiseError => 1 } );
    
        # Or, simply pass an existing database handle as the only argument ...
        #
        MyDB($dbh);
  • Use them to represent database handles

        use DBIx::FlexibleBinding -subs => [ 'MyDB' ];
        use constant SQL => << '//';
        SELECT *
          FROM mapsolarsystems
         WHERE regional  = :is_regional
           AND security >= :minimum_security
        //
    
        MyDB( 'dbi:mysql:test;host=127.0.0.1', '', '', { RaiseError => 1 } );
    
        # If your name is already associated with a database handle then just call
        # it with no parameters to use it as such ...
        #
        my $sth = MyDB->prepare(SQL);
  • Use them to represent statement handles

        use DBIx::FlexibleBinding -subs => [ 'MyDB', 'solar_systems' ];
        use constant SQL => << '//';
        SELECT *
          FROM mapsolarsystems
         WHERE regional  = :is_regional
           AND security >= :minimum_security
        //
    
        MyDB( 'dbi:mysql:test;host=127.0.0.1', '', '', { RaiseError => 1 } );
    
        my $sth = MyDB->prepare(SQL);
    
        # Simply call the statement handle proxy, passing a statement handle in as
        # the only argument ...
        #
        solar_systems($sth);
  • Use to interact with the represented database and statement handles

        use DBIx::FlexibleBinding -subs => [ 'MyDB', 'solar_systems' ];
        use constant SQL => << '//';
        SELECT *
          FROM mapsolarsystems
         WHERE regional  = :is_regional
           AND security >= :minimum_security
        //
    
        MyDB( 'dbi:mysql:test;host=127.0.0.1', '', '', { RaiseError => 1 } );
    
        # Use the database handle proxy to prepare, bind and execute statements, then
        # retrieve the results ...
        #
        # Use the database handle proxy to prepare, bind and execute statements, then
        # retrieve the results ...
        #
        my $array_of_hashrefs = MyDB(SQL,
                                     is_regional => 1,
                                     minimum_security => 1.0);
    
        # In list context, results come back as lists ...
        #
        my @array_of_hashrefs = MyDB(SQL,
                                     is_regional => 1,
                                     minimum_security => 1.0);
    
        # You can use proxies to represent statements, too. Simply pass in a statement
        # handle as the only argument ...
        #
        my $sth = MyDB->prepare(SQL);
        solar_systems($sth);    # Using "solar_systems" as statement proxy.
    
        # Now, when called with other types of arguments, those argument values are
        # bound and the statement is executed ...
        #
        my $array_of_hashrefs = solar_systems(is_regional => 1,
                                              minimum_security => 1.0);
    
        # In list context, results come back as lists ...
        #
        my @array_of_hashrefs = solar_systems(is_regional => 1,
                                              minimum_security => 1.0);
    
        # Statements requiring no parameters cannot be used in this manner because
        # making a call to a statement proxy with an arity of zero results in the
        # statement handle being returned. In this situation, use something like
        # undef as an argument (it will be ignored in this particular instance) ...
        #
        my $rv = statement_proxy(undef);
        #
        # Meh, you can't win 'em all!

PACKAGE GLOBALS

$DBIx::FlexibleBinding::AUTO_BINDING_ENABLED

A boolean setting used to determine whether or not automatic binding is enabled or disabled globally.

The default setting is "1" (enabled).

IMPORT TAGS AND OPTIONS

-alias

This option may be used by the caller to select an alias to use for this package's unwieldly namespace.

    use DBIx::FlexibleBinding -alias => 'DBIF';

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

-subs

This option may be used to create subroutines, during the compile phase, in the caller's namespace to be used as representations of database and statement handles.

    use DBIx::FlexibleBinding -subs => [ 'MyDB' ];

    # Initialise by passing in a valid set of DBI->connect(...) arguments.
    # The database handle will be the return value.
    #
    MyDB 'dbi:mysql:test;host=127.0.0.1', '', '', { RaiseError => 1 };

    # Or, initialise by passing in a DBI database handle.
    # The handle is also the return value.
    #
    MyDB $dbh;

    # Once initialised, use the subroutine as you would a DBI database handle.
    #
    my $statement = << '//';
    SELECT solarSystemName AS name
      FROM mapsolarsystems
     WHERE security >= :minimum_security
    //
    my $sth = MyDB->prepare($statement);

    # Or use it as an expressive time-saver!
    #
    my $array_of_hashrefs = MyDB($statement, security => 1.0);
    my @system_names = MyDB($statement, minimum_security => 1.0, callback {
        return $_->{name};
    });
    MyDB $statement, minimum_security => 1.0, callback {
        my ($row) = @_;
        print "$row->{name}\n";
    };

CLASS METHODS

connect

    $dbh = DBIx::FlexibleBinding->connect($data_source, $user, $pass)
      or die $DBI::errstr;
    $dbh = DBIx::FlexibleBinding->connect($data_source, $user, $pass, \%attr)
      or die $DBI::errstr;

Establishes a database connection, or session, to the requested data_source and returns a database handle object if the connection succeeds or undef if it does not.

Refer to http://search.cpan.org/dist/DBI/DBI.pm#connect for a more detailed description of this method.

DATABASE HANDLE METHODS

do

    $rows = $dbh->do($statement_string) or die $dbh->errstr;
    $rows = $dbh->do($statement_string, @bind_values) or die $dbh->errstr;
    $rows = $dbh->do($statement_string, \%attr) or die $dbh->errstr;
    $rows = $dbh->do($statement_string, \%attr, @bind_values) or die $dbh->errstr;
    $rows = $dbh->do($statement_handle) or die $dbh->errstr;
    $rows = $dbh->do($statement_handle, @bind_values) or die $dbh->errstr;

Prepares (if necessary) and executes a single statement. Returns the number of rows affected or undef on error. A return value of -1 means the number of rows is not known, not applicable, or not available. When no rows have been affected this method continues the DBI tradition of returning 0E0 on successful execution and undef on failure.

The do method accepts optional callbacks for further processing of the result.

The do implementation provided by this module allows for some minor deviations in usage over the standard DBI implementation. In spite of this, the new method may be used just like the original.

Refer to http://search.cpan.org/dist/DBI/DBI.pm#do for a more detailed description of this method.

Examples

1. Statement attributes are now optional:
    $sql = << '//';
    UPDATE employees
       SET salary = :salary
     WHERE employee_id = :employee_id
    //

    $dbh->do($sql, employee_id => 52, salary => 35_000)
      or die $dbh->errstr;

A reference to the statement attributes hash is no longer required, even if it's empty. If, however, a hash reference is supplied as the first parameter then it would be used for that purpose.

2. Prepared statements now may be re-used:
    $sth = $dbh->prepare(<< '//');
    UPDATE employees
       SET salary = ?
     WHERE employee_id = ?
    //

    $dbh->do($sth, 35_000, 52) or die $dbh->errstr;

A prepared statement may also be used in lieu of a statement string. In such cases, referencing a statement attributes hash is neither required nor expected.

prepare

    $sth = $dbh->prepare($statement_string);
    $sth = $dbh->prepare($statement_string, \%attr);

Prepares a statement for later execution by the database engine and returns a reference to a statement handle object.

Refer to http://search.cpan.org/dist/DBI/DBI.pm#prepare for a more detailed description of this method.

Examples

1. Prepare a statement using positional placeholders:
    $sql = << '//';
    UPDATE employees
       SET salary = ?
     WHERE employee_id = ?
    //

    $sth = $dbh->prepare($sql);
2. Prepare a statement using named placeholders:

(Yes, even for those MySQL connections!)

    $sql = << '//';
    UPDATE employees
       SET salary = :salary
     WHERE employee_id = :employee_id
    //

    $sth = $dbh->prepare($sql);

getrows_arrayref (database handles)

    $results = $dbh->getrows_arrayref($statement_string, @bind_values);
    @results = $dbh->getrows_arrayref($statement_string, @bind_values);
    $results = $dbh->getrows_arrayref($statement_string, \%attr, @bind_values);
    @results = $dbh->getrows_arrayref($statement_string, \%attr, @bind_values);
    $results = $dbh->getrows_arrayref($statement_handle, @bind_values);
    @results = $dbh->getrows_arrayref($statement_handle, @bind_values);

Prepares (if necessary) and executes a single statement with the specified data bindings and fetches the result set as an array of array references.

The getrows_arrayref method accepts optional callbacks for further processing of the results by the caller.

Examples

1. Prepare, execute it then get the results as a reference:
    $sql = << '//';
    SELECT solarSystemName AS name
         , security
      FROM mapsolarsystems
     WHERE regional  = 1
       AND security >= :minimum_security
    //

    $systems = $dbh->getrows_arrayref($sql, minimum_security => 1.0);

    # Returns a structure something like this:
    #
    # [ [ 'Kisogo',      '1' ],
    #   [ 'New Caldari', '1' ],
    #   [ 'Amarr',       '1' ],
    #   [ 'Bourynes',    '1' ],
    #   [ 'Ryddinjorn',  '1' ],
    #   [ 'Luminaire',   '1' ],
    #   [ 'Duripant',    '1' ],
    #   [ 'Yulai',       '1' ] ]
2. Re-use a prepared statement, execute it then return the results as a list:

We'll use the query from Example 1 but have the results returned as a list for further processing by the caller.

    $sth = $dbh->prepare($sql);

    @systems = $dbh->getrows_arrayref($sql, minimum_security => 1.0);

    for my $system (@systems) {
        printf "%-11s %.1f\n", @$system;
    }

    # Output:
    #
    # Kisogo      1.0
    # New Caldari 1.0
    # Amarr       1.0
    # Bourynes    1.0
    # Ryddinjorn  1.0
    # Luminaire   1.0
    # Duripant    1.0
    # Yulai       1.0
3. Re-use a prepared statement, execute it then return modified results as a reference:

We'll use the query from Example 1 but have the results returned as a list for further processing by a caller who will be using callbacks to modify those results.

    $sth = $dbh->prepare($sql);

    $systems = $dbh->getrows_arrayref($sql, minimum_security => 1.0, callback {
        my ($row) = @_;
        return sprintf("%-11s %.1f\n", @$row);
    });

    # Returns a structure something like this:
    #
    # [ 'Kisogo      1.0',
    #   'New Caldari 1.0',
    #   'Amarr       1.0',
    #   'Bourynes    1.0',
    #   'Ryddinjorn  1.0',
    #   'Luminaire   1.0',
    #   'Duripant    1.0',
    #   'Yulai       1.0' ]

getrows_hashref (database handles)

    $results = $dbh->getrows_hashref($statement_string, @bind_values);
    @results = $dbh->getrows_hashref($statement_string, @bind_values);
    $results = $dbh->getrows_hashref($statement_string, \%attr, @bind_values);
    @results = $dbh->getrows_hashref($statement_string, \%attr, @bind_values);
    $results = $dbh->getrows_hashref($statement_handle, @bind_values);
    @results = $dbh->getrows_hashref($statement_handle, @bind_values);

Prepares (if necessary) and executes a single statement with the specified data bindings and fetches the result set as an array of hash references.

The getrows_hashref method accepts optional callbacks for further processing of the results by the caller.

Examples

1. Prepare, execute it then get the results as a reference:
    $sql = << '//';
    SELECT solarSystemName AS name
         , security
      FROM mapsolarsystems
     WHERE regional  = 1
       AND security >= :minimum_security
    //

    $systems = $dbh->getrows_hashref($sql, minimum_security => 1.0);

    # Returns a structure something like this:
    #
    # [ { name => 'Kisogo',      security => '1' },
    #   { name => 'New Caldari', security => '1' },
    #   { name => 'Amarr',       security => '1' },
    #   { name => 'Bourynes',    security => '1' },
    #   { name => 'Ryddinjorn',  security => '1' },
    #   { name => 'Luminaire',   security => '1' },
    #   { name => 'Duripant',    security => '1' },
    #   { name => 'Yulai',       security => '1' } ]
2. Re-use a prepared statement, execute it then return the results as a list:

We'll use the query from Example 1 but have the results returned as a list for further processing by the caller.

    $sth = $dbh->prepare($sql);

    @systems = $dbh->getrows_hashref($sql, minimum_security => 1.0);

    for my $system (@systems) {
        printf "%-11s %.1f\n", @{$system}{'name', 'security'}; # Hash slice
    }

    # Output:
    #
    # Kisogo      1.0
    # New Caldari 1.0
    # Amarr       1.0
    # Bourynes    1.0
    # Ryddinjorn  1.0
    # Luminaire   1.0
    # Duripant    1.0
    # Yulai       1.0
3. Re-use a prepared statement, execute it then return modified results as a reference:

We'll use the query from Example 1 but have the results returned as a list for further processing by a caller who will be using callbacks to modify those results.

    $sth = $dbh->prepare($sql);

    $systems = $dbh->getrows_hashref($sql, minimum_security => 1.0, callback {
        sprintf("%-11s %.1f\n", @{$_}{'name', 'security'}); # Hash slice
    });

    # Returns a structure something like this:
    #
    # [ 'Kisogo      1.0',
    #   'New Caldari 1.0',
    #   'Amarr       1.0',
    #   'Bourynes    1.0',
    #   'Ryddinjorn  1.0',
    #   'Luminaire   1.0',
    #   'Duripant    1.0',
    #   'Yulai       1.0' ]

getrows (database handles)

    $results = $dbh->getrows($statement_string, @bind_values);
    @results = $dbh->getrows($statement_string, @bind_values);
    $results = $dbh->getrows($statement_string, \%attr, @bind_values);
    @results = $dbh->getrows($statement_string, \%attr, @bind_values);
    $results = $dbh->getrows($statement_handle, @bind_values);
    @results = $dbh->getrows$statement_handle, @bind_values);

Alias for getrows_hashref.

If array references are preferred, have the symbol table glob point alias the getrows_arrayref method.

The getrows method accepts optional callbacks for further processing of the results by the caller.

getrow_arrayref (database handles)

    $result = $dbh->getrow_arrayref($statement_string, @bind_values);
    $result = $dbh->getrow_arrayref($statement_string, \%attr, @bind_values);
    $result = $dbh->getrow_arrayref($statement_handle, @bind_values);

Prepares (if necessary) and executes a single statement with the specified data bindings and fetches the first row as an array reference.

The getrow_arrayref method accepts optional callbacks for further processing of the result by the caller.

getrow_hashref (database handles)

    $result = $dbh->getrow_hashref($statement_string, @bind_values);
    $result = $dbh->getrow_hashref($statement_string, \%attr, @bind_values);
    $result = $dbh->getrow_hashref($statement_handle, @bind_values);

Prepares (if necessary) and executes a single statement with the specified data bindings and fetches the first row as a hash reference.

The getrow_hashref method accepts optional callbacks for further processing of the result by the caller.

getrow (database handles)

    $result = $dbh->getrow($statement_string, @bind_values);
    $result = $dbh->getrow($statement_string, \%attr, @bind_values);
    $result = $dbh->getrow($statement_handle, @bind_values);

Alias for getrow_hashref.

If array references are preferred, have the symbol table glob point alias the getrows_arrayref method.

The getrow method accepts optional callbacks for further processing of the result by the caller.

STATEMENT HANDLE METHODS

bind_param

    $sth->bind_param($param_num, $bind_value)
    $sth->bind_param($param_num, $bind_value, \%attr)
    $sth->bind_param($param_num, $bind_value, $bind_type)

    $sth->bind_param($param_name, $bind_value)
    $sth->bind_param($param_name, $bind_value, \%attr)
    $sth->bind_param($param_name, $bind_value, $bind_type)

The bind_param method associates (binds) a value to a placeholder embedded in the prepared statement. The implementation provided by this module allows the use of parameter names, if appropriate, in addition to parameter positions.

Refer to http://search.cpan.org/dist/DBI/DBI.pm#bind_param for a more detailed explanation of how to use this method.

execute

    $rv = $sth->execute() or die $DBI::errstr;
    $rv = $sth->execute(@bind_values) or die $DBI::errstr;

Perform whatever processing is necessary to execute the prepared statement. An undef is returned if an error occurs. A successful call returns true regardless of the number of rows affected, even if it's zero.

Refer to http://search.cpan.org/dist/DBI/DBI.pm#execute for a more detailed description of this method.

Examples

Use prepare, execute and getrow_hashref with a callback to modify my data:
    use strict;
    use warnings;

    use DBIx::FlexibleBinding -subs => [ 'TestDB' ];
    use Data::Dumper;
    use Test::More;

    $Data::Dumper::Terse  = 1;
    $Data::Dumper::Indent = 1;

    TestDB 'dbi:mysql:test', '', '', { RaiseError => 1 };

    my $sth = TestDB->prepare(<< '//');
       SELECT solarSystemID   AS id
            , solarSystemName AS name
            , security
         FROM mapsolarsystems
        WHERE solarSystemName RLIKE "^U[^0-9\-]+$"
     ORDER BY id, name, security DESC
        LIMIT 5
    //

    $sth->execute() or die $DBI::errstr;

    my @rows;
    my @callback_list = (
        callback {
            my ($row) = @_;
            $row->{filled_with} = ( $row->{security} >= 0.5 )
                ? 'Carebears' : 'Yarrbears';
            $row->{security} = sprintf('%.1f', $row->{security});
            return $row;
        }
    );

    while ( my $row = $sth->getrow_hashref(@callback_list) ) {
        push @rows, $row;
    }

    my $expected_result = [
       {
         'name' => 'Uplingur',
         'filled_with' => 'Yarrbears',
         'id' => '30000037',
         'security' => '0.4'
       },
       {
         'security' => '0.4',
         'id' => '30000040',
         'name' => 'Uzistoon',
         'filled_with' => 'Yarrbears'
       },
       {
         'name' => 'Usroh',
         'filled_with' => 'Carebears',
         'id' => '30000068',
         'security' => '0.6'
       },
       {
         'filled_with' => 'Yarrbears',
         'name' => 'Uhtafal',
         'id' => '30000101',
         'security' => '0.5'
       },
       {
         'security' => '0.3',
         'id' => '30000114',
         'name' => 'Ubtes',
         'filled_with' => 'Yarrbears'
       }
    ];

    is_deeply( \@rows, $expected_result, 'iterate' )
        and diag( Dumper(\@rows) );
    done_testing();

iterate

    $iterator = $sth->iterate() or die $DBI::errstr;
    $iterator = $sth->iterate(@bind_values) or die $DBI::errstr;

Perform whatever processing is necessary to execute the prepared statement. An undef is returned if an error occurs. A successful call returns an iterator which can be used to traverse the result set.

Examples

1. Using an iterator and callbacks to process the result set:
    use strict;
    use warnings;

    use DBIx::FlexibleBinding -subs => [ 'TestDB' ];
    use Data::Dumper;
    use Test::More;

    $Data::Dumper::Terse  = 1;
    $Data::Dumper::Indent = 1;

    my @drivers = grep { /^SQLite$/ } DBI->available_drivers();

    SKIP: {
      skip("iterate tests (No DBD::SQLite installed)", 1) unless @drivers;

      TestDB "dbi:SQLite:test.db", '', '', { RaiseError => 1 };

      my $sth = TestDB->prepare(<< '//');
       SELECT solarSystemID   AS id
            , solarSystemName AS name
            , security
         FROM mapsolarsystems
        WHERE solarSystemName REGEXP "^U[^0-9\-]+$"
     ORDER BY id, name, security DESC
        LIMIT 5
    //

    # Iterate over the result set
    # ---------------------------
    # We also queue up a sneaky callback to modify each row of data as it
    # is fetched from the result set.

      my $it = $sth->iterate( callback {
          my ($row) = @_;
          $row->{filled_with} = ( $row->{security} >= 0.5 )
              ? 'Carebears' : 'Yarrbears';
          $row->{security} = sprintf('%.1f', $row->{security});
          return $row;
      } );

      my @rows;
      while ( my $row = $it->() ) {
          push @rows, $row;
      }

    # Done, now check the results ...

      my $expected_result = [
         {
           'name' => 'Uplingur',
           'filled_with' => 'Yarrbears',
           'id' => '30000037',
           'security' => '0.4'
         },
         {
           'security' => '0.4',
           'id' => '30000040',
           'name' => 'Uzistoon',
           'filled_with' => 'Yarrbears'
         },
         {
           'name' => 'Usroh',
           'filled_with' => 'Carebears',
           'id' => '30000068',
           'security' => '0.6'
         },
         {
           'filled_with' => 'Yarrbears',
           'name' => 'Uhtafal',
           'id' => '30000101',
           'security' => '0.5'
         },
         {
           'security' => '0.3',
           'id' => '30000114',
           'name' => 'Ubtes',
           'filled_with' => 'Yarrbears'
         }
      ];

      is_deeply( \@rows, $expected_result, 'iterate' )
          and diag( Dumper(\@rows) );
    }

    done_testing();

In this example, we're traversing the result set using an iterator. As we iterate through the result set, a callback is applied to each row and we're left with an array of transformed rows.

2. Using an iterator's for_each method and callbacks to process the result set:
    use strict;
    use warnings;

    use DBIx::FlexibleBinding -subs => [ 'TestDB' ];
    use Data::Dumper;
    use Test::More;

    $Data::Dumper::Terse  = 1;
    $Data::Dumper::Indent = 1;

    my @drivers = grep { /^SQLite$/ } DBI->available_drivers();

    SKIP: {
      skip("iterate tests (No DBD::SQLite installed)", 1) unless @drivers;

      TestDB "dbi:SQLite:test.db", '', '', { RaiseError => 1 };

      my $sth = TestDB->prepare(<< '//');
       SELECT solarSystemID   AS id
            , solarSystemName AS name
            , security
         FROM mapsolarsystems
        WHERE solarSystemName REGEXP "^U[^0-9\-]+$"
     ORDER BY id, name, security DESC
        LIMIT 5
    //

    # Iterate over the result set
    # ---------------------------
    # This time around we call the iterator's "for_each" method to process
    # the data. Bonus: we haven't had to store the iterator anywhere or
    # pre-declare an empty array to accommodate our rows.

      my @rows = $sth->iterate->for_each( callback {
          my ($row) = @_;
          $row->{filled_with} = ( $row->{security} >= 0.5 )
              ? 'Carebears' : 'Yarrbears';
          $row->{security} = sprintf('%.1f', $row->{security});
          return $row;
      } );

    # Done, now check the results ...

      my $expected_result = [
         {
           'name' => 'Uplingur',
           'filled_with' => 'Yarrbears',
           'id' => '30000037',
           'security' => '0.4'
         },
         {
           'security' => '0.4',
           'id' => '30000040',
           'name' => 'Uzistoon',
           'filled_with' => 'Yarrbears'
         },
         {
           'name' => 'Usroh',
           'filled_with' => 'Carebears',
           'id' => '30000068',
           'security' => '0.6'
         },
         {
           'filled_with' => 'Yarrbears',
           'name' => 'Uhtafal',
           'id' => '30000101',
           'security' => '0.5'
         },
         {
           'security' => '0.3',
           'id' => '30000114',
           'name' => 'Ubtes',
           'filled_with' => 'Yarrbears'
         }
      ];

      is_deeply( \@rows, $expected_result, 'iterate' )
          and diag( Dumper(\@rows) );
    }

    done_testing();

Like the previous example, we're traversing the result set using an iterator but this time around we have done away with $it in favour of calling the iterator's own for_each method. The callback we were using to process each row of the result set has now been passed into the for_each method also eliminating a while loop and an empty declaration for @rows.

getrows_arrayref (database handles)

    $results = $sth->getrows_arrayref();
    @results = $sth->getrows_arrayref();

Fetches the entire result set as an array of array references.

The getrows_arrayref method accepts optional callbacks for further processing of the results by the caller.

getrows_hashref (database handles)

    $results = $sth->getrows_hashref();
    @results = $sth->getrows_hashref();

Fetches the entire result set as an array of hash references.

The getrows_hashref method accepts optional callbacks for further processing of the results by the caller.

getrows (database handles)

    $results = $sth->getrows();
    @results = $sth->getrows();

Alias for getrows_hashref.

If array references are preferred, have the symbol table glob point alias the getrows_arrayref method.

The getrows method accepts optional callbacks for further processing of the results by the caller.

getrow_arrayref (database handles)

    $result = $sth->getrow_arrayref();

Fetches the next row as an array reference. Returns undef if there are no more rows available.

The getrow_arrayref method accepts optional callbacks for further processing of the result by the caller.

getrow_hashref (database handles)

    $result = $sth->getrow_hashref();

Fetches the next row as a hash reference. Returns undef if there are no more rows available.

The getrow_hashref method accepts optional callbacks for further processing of the result by the caller.

getrow (database handles)

    $result = $sth->getrow();

Alias for getrow_hashref.

If array references are preferred, have the symbol table glob point alias the getrows_arrayref method.

The getrow method accepts optional callbacks for further processing of the result by the caller.

EXPORTS

The following symbols are exported by default:

callback

To enable the namespace using this module to take advantage of the callbacks, which are one of its main features, without the unnecessary burden of also including the module that provides the feature (see Params::Callbacks for more detailed information).

SEE ALSO

REPOSITORY

BUGS

Please report any bugs or feature requests to bug-dbix-anybinding at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=DBIx-FlexibleBinding. 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::FlexibleBinding

You can also look for information at:

ACKNOWLEDGEMENTS

Many, many thanks to the CPANTesters network.

Test data set extracted from Fuzzwork's MySQL conversion of CCP's EVE Online Static Data Export:

Eternal gratitude to GitHub contributors:

AUTHOR

Iain Campbell <cpanic@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2012-2015 by Iain Campbell.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.