=head1 NAME

SQL::Executor - Thin DBI wrapper using SQL::Maker

=head1 SYNOPSIS

  use DBI;
  use SQL::Executor;
  my $dbh = DBI->connect($dsn, $id, $pass);
  my $ex = SQL::Executor->new($dbh);
  #
  # SQL::Maker-like interfaces
  my @rows = $ex->select('SOME_TABLE', { id => 123 });
  $ex->insert('SOME_TABLE', { id => 124, value => 'xxxx'} );
  $ex->update('SOME_TABLE', { value => 'yyyy'}, { id => 124 } );
  $ex->delete('SOME_TABLE', { id => 124 } );
  #
  # select using SQL with named placeholder
  my @rows= $ex->select_named('SELECT id, value1 FROM SOME_TABLE WHERE value2 = :arg1', { arg1 => 'aaa' });

=head1 DESCRIPTION

SQL::Executor is thin DBI wrapper using L<SQL::Maker>. This module provides interfaces to make easier access to SQL.

You can execute SQL via SQL::Maker-like interface in select(), select_row(), select_all(), select_with_fields(), select_row_with_fields(), select_all_with_fields(), insert(), insert_multi(), update() and delete().

If you want to use more complex select query, you can use select_named(), select_row_named() or select_all_named() these execute SQL with named placeholder. If you don't want to use named placeholder, you can use select_by_sql(), select_row_by_sql() or select_all_by_sql() these execute SQL with normal placeholder('?').


=cut

=head1 METHODS


=cut

=head2 new($dbh, $option_href)

$dbh: Database Handler
$option_href: option

available option is as follows

=over 4

=item * allow_empty_condition (BOOL default 1): allow empty condition(where) in select/delete/update

=item * callback (coderef): specify callback coderef. callback is called for each select* method

=item * check_empty_bind (BOOL default 0): if TRUE(1), select*_named() do not accept unbound parameter, see named_bind() for detail.

=back

These callbacks are useful for making row object.

  my $ex = SQL::Executor->new($dbh, {
      callback => sub {
          my ($self, $row, $table_name, $select_id) = @_;
          return CallBack::Class->new($row);
      },
  });

  my $row = $ex->select_by_sql($sql1, \@binds1, 'TEST');
  # $row isa 'CallBack::Class'



=cut

=head2 connect($dsn, $user, $pass, $option_for_dbi, $option_href)

$dsn: DSN
$user: database user
$pass: database password
$option_href_for_dbi: options passed to DBI
$option_href: option for SQL::Executor (options are same as new() method)

connect database and create SQL::Executor instance. using this method, SQL::Executor uses
managed connection and transaction via L<DBIx::Handler>


=cut

=head2 dbh()

return database handler


=cut

=head2 select($table_name, $where, $option)

select row(s). parameter is the same as select method in L<SQL::Maker>. But array ref for filed names are not needed.
In array context, this method behaves the same as select_all. In scalar context, this method behaves the same as select_one


=cut

=head2 select_row($table_name, $where, $option)

select only one row. parameter is the same as select method in L<SQL::Maker>. But array ref for filed names are not needed.
this method returns hash ref and it is the same as return value in DBI's selectrow_hashref/fetchrow_hashref.


=cut

=head2 select_all($table_name, $where, $option)

select all rows. parameter is the same as select method in L<SQL::Maker>. But array ref for filed names are not needed.
this method returns array that is composed of hash refs. (hash ref is same as DBI's selectrow_hashref/fetchrow_hashref).


=cut

=head2 select_itr($table_name, $where, $option)

select and returns iterator. parameter is the same as select method in L<SQL::Maker>. But array ref for field names are not needed.
Iterator is L<SQL::Executor::Iterator> object.

  my $itr = select_itr('SOME_TABLE', { name => 'aaa' });
  while( my $row = $itr->next ) {
      # ... using row
  }


=cut

=head2 select_named($sql, $params_href, $table_name)

select row(s). In array context, this method behaves the same as select_all_with_fields.
In scalar context, this method behaves the same as select_one_with_fileds

You can use named placeholder in SQL like this,

  my $ex = SQL::Executor->new($dbh);
  my $row = $ex->select_named("SELECT * FROM SOME_TABLE WHERE id = :id", { id => 1234 });

$table_name is used for callback.


=cut

=head2 select_row_named($sql, $params_href, $table_name)

select only one row. You can use named placeholder in SQL like this,

  my $ex = SQL::Executor->new($dbh);
  my $row = $ex->select_row_named("SELECT * FROM SOME_TABLE WHERE id = :id", { id => 1234 });

this method returns hash ref and it is the same as return value in DBI's selectrow_hashref/fetchrow_hashref.

$table_name is used for callback.


=cut

=head2 select_all_named($sql, $params_href, $table_name)

select all rows. You can use named placeholder in SQL like this,

  my $ex = SQL::Executor->new($dbh);
  my @rows = $ex->select_all_named("SELECT * FROM SOME_TABLE WHERE id = :id", { id => 1234 });

this method returns array that is composed of hash refs. (hash ref is same as DBI's selectrow_hashref/fetchrow_hashref).
$table_name is used for callback.


=cut

=head2 select_itr_named($sql, $params_href, $table_name)

select and returns iterator. You can use named placeholder in SQL like this,

  my $ex = SQL::Executor->new($dbh);
  my $itr = $ex->select_itr_named("SELECT * FROM SOME_TABLE WHERE id = :id", { id => 1234 });

$table_name is used for callback.


=cut

=head2 named_bind($sql, $params_href, $check_empty_bind)

returns sql which is executable in execute_query() and parameters for bind.

  my ($sql, @binds) = named_bind("SELECT * FROM SOME_TABLE WHERE id = :id", { id => 123 });
  # $sql   =>  "SELECT * FROM SOME_TABLE WHERE id = ?"
  # @binds => (123)

parameter $check_empty_bind is optional. By default (or set $check_empty_bind=0), 
named_bind() accepts unbound parameter like this,

  my ($sql, @binds) = named_bind("SELECT * FROM SOME_TABLE WHERE id = :id", { });# do not bind :id
  # $sql   =>  "SELECT * FROM SOME_TABLE WHERE id = ?"
  # @binds => (undef)

if $check_empty_bind is 1, named_bind() dies when unbound parameter is specified.


=cut

=head2 select_by_sql($sql, \@binds, $table_name)

select row(s). In array context, this method behaves the same as select_all_with_fields.
In scalar context, this method behaves the same as select_one_with_fileds

  my $ex = SQL::Executor->new($dbh);
  my $row = $ex->select_by_sql("SELECT * FROM SOME_TABLE WHERE id = ?", [1234]);

$table_name is only used for callback.


=cut

=head2 select_row_by_sql($sql, \@binds, $table_name)

select only one row.

  my $ex = SQL::Executor->new($dbh);
  my $row = $ex->select_row_by_sql("SELECT * FROM SOME_TABLE WHERE id = ?", [1234]);

this method returns hash ref and it is the same as return value in DBI's selectrow_hashref/fetchrow_hashref.


=cut

=head2 select_all_by_sql($sql, \@binds, $table_name)

select all rows.

  my $ex = SQL::Executor->new($dbh);
  my @rows = $ex->select_all_by_sql("SELECT * FROM SOME_TABLE WHERE id = ?", [1234]);

this method returns array that is composed of hash refs. (hash ref is same as DBI's selectrow_hashref/fetchrow_hashref).


=cut

=head2 select_itr_by_sql($sql, \@binds, $table_name)

select and returns iterator

  my $ex = SQL::Executor->new($dbh);
  my $itr = $ex->select_itr_by_sql("SELECT * FROM SOME_TABLE WHERE id = ?", [1234]);

Iterator is L<SQL::Executor::Iterator> object.


=cut

=head2 select_with_fields($table_name, $fields_aref, $where, $option)

select row(s). parameter is the same as select method in L<SQL::Maker>. 
In array context, this method behaves the same as select_all_with_fields.
In scalar context, this method behaves the same as select_one_with_fileds


=cut

=head2 select_row_with_fields($table_name, $fields_aref, $where, $option)

select only one row. parameter is the same as select method in L<SQL::Maker>.
this method returns hash ref and it is the same as return value in DBI's selectrow_hashref/fetchrow_hashref.


=cut

=head2 select_all_with_fields($table_name, $fields_aref, $where, $option)

select all rows. parameter is the same as select method in L<SQL::Maker>. But array ref for filed names are not needed.
this method returns array that is composed of hash refs. (hash ref is same as DBI's selectrow_hashref/fetchrow_hashref).


=cut

=head2 select_itr_with_fields($table_name, $fields_aref, $where, $option)

select and return iterator object(L<SQL::Executor::Iterator>). parameter is the same as select method in L<SQL::Maker>.


=cut

=head2 insert($table_name, $values)

Do INSERT statement. parameter is the same as select method in L<SQL::Maker>.


=cut

=head2 insert_multi($table_name, @args)

Do INSERT-multi statement using L<SQL::Maker::Plugin::InsertMulti>.


=cut

=head2 insert_on_duplicate($table_name, $insert_value_href, $update_value_href)

Do "INSERT ... ON DUPLICATE KEY UPDATE" query (works only MySQL) using L<SQL::Maker::Plugin::InsertOnDuplicate>.

this method is available when L<SQL::Maker> >= 1.09 is installed. If older version is installed, you will
got error like "Can't locate SQL/Maker/Plugin/InsertOnDuplicate.pm in @INC ..."


=cut

=head2 delete($table_name, $where)

Do DELETE statement. parameter is the same as select method in L<SQL::Maker>.


=cut

=head2 update($table_name, $set, $where)

Do UPDATE statement. parameter is the same as select method in L<SQL::Maker>.


=cut

=head2 execute_query($sql, \@binds)

execute query and returns statement handler($sth).


=cut

=head2 execute_query_named($sql, $params_href)

execute query with named placeholder and returns statement handler($sth).


=cut

=head2 disable_callback()

disable callback temporarily, 


=cut

=head2 restore_callback()

restore disabled callback.


=cut

=head2 last_insert_id(@args)

If driver is mysql, return $dbh->{mysql_insertid}.If driver is SQLite, return $dbh->sqlite_last_insert_rowid.
If other driver is used, return $dbh->last_insert_id(@args)


=cut

=head2 handle_exception($sql, $binds_aref, $err_message)

show error message. you can override this method in subclass to provide
customized error message.

default error message is like this,

Error <I>$error_message</I> sql: <I>$sql</I>, binds: [<I>$binds_aref</I>]\n


=cut

=head2 select_id()

generate id for select statament. but by default, id is not generated.
If you want to generate id, please override


=cut

=head1 How to use Transaction.

When create instance using connect() method, you can use L<DBIx::Handler>'s
transaction management, 

  use SQL::Executor;
  my $ex = SQL::Executor->connect($dsn, $id, $pass);
  my $txn = $ex->handler->txn_scope();
  $ex->insert('SOME_TABLE', { id => 124, value => 'xxxx'} );
  $ex->insert('SOME_TABLE', { id => 125, value => 'yyy'} );
  $txn->commit();


Or You can use L<DBI>'s transaction (begin_work and commit).

  use DBI;
  use SQL::Executor;
  my $dbh = DBI->connect($dsn, $id, $pass);
  my $ex = SQL::Executor->new($dbh);
  $dbh->begin_work();
  $ex->insert('SOME_TABLE', { id => 124, value => 'xxxx'} );
  $ex->insert('SOME_TABLE', { id => 125, value => 'yyy'} );
  $dbh->commit();


Or you can also use transaction management modules like L<DBIx::TransactionManager>.

  use DBI;
  use SQL::Executor;
  use DBIx::TransactionManager;
  my $dbh = DBI->connect($dsn, $id, $pass);
  my $ex = SQL::Executor->new($dbh);
  my $tm = DBIx::TransactionManager->new($dbh);
  my $txn = $tm->txn_scope;
  $ex->insert('SOME_TABLE', { id => 124, value => 'xxxx'} );
  $ex->insert('SOME_TABLE', { id => 125, value => 'yyy'} );
  $txn->commit;

=head1 FAQ

=head2 Why don't you use L<DBIx::Simple>?

=over 4

=item * I want to use L<SQL::Maker>.

=item * When I need to use complex query, I want to use named placeholder.

=back

=head1 AUTHOR

Takuya Tsuchida E<lt>tsucchi {at} cpan.orgE<gt>

=head1 SEE ALSO

L<DBI>, L<SQL::Maker>, L<DBIx::Simple>

Codes for named placeholder is taken from L<Teng>'s search_named.

=head1 LICENSE

Copyright (C) Takuya Tsuchida

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


=cut

