1 package DBIx::Class::Storage::DBI;
2 # -*- mode: cperl; cperl-indent-level: 2 -*-
4 use base 'DBIx::Class::Storage';
8 use Carp::Clan qw/^DBIx::Class/;
10 use DBIx::Class::Storage::DBI::Cursor;
11 use DBIx::Class::Storage::Statistics;
15 __PACKAGE__->mk_group_accessors('simple' =>
16 qw/_connect_info _dbi_connect_info _dbh _sql_maker _sql_maker_opts
17 _conn_pid _conn_tid transaction_depth _dbh_autocommit savepoints/
20 # the values for these accessors are picked out (and deleted) from
21 # the attribute hashref passed to connect_info
22 my @storage_options = qw/
23 on_connect_do on_disconnect_do disable_sth_caching unsafe auto_savepoint
25 __PACKAGE__->mk_group_accessors('simple' => @storage_options);
28 # default cursor class, overridable in connect_info attributes
29 __PACKAGE__->cursor_class('DBIx::Class::Storage::DBI::Cursor');
31 __PACKAGE__->mk_group_accessors('inherited' => qw/sql_maker_class/);
32 __PACKAGE__->sql_maker_class('DBIx::Class::SQLAHacks');
37 DBIx::Class::Storage::DBI - DBI storage handler
41 my $schema = MySchema->connect('dbi:SQLite:my.db');
43 $schema->storage->debug(1);
44 $schema->dbh_do("DROP TABLE authors");
46 $schema->resultset('Book')->search({
47 written_on => $schema->storage->datetime_parser(DateTime->now)
52 This class represents the connection to an RDBMS via L<DBI>. See
53 L<DBIx::Class::Storage> for general information. This pod only
54 documents DBI-specific methods and behaviors.
61 my $new = shift->next::method(@_);
63 $new->transaction_depth(0);
64 $new->_sql_maker_opts({});
65 $new->{savepoints} = [];
66 $new->{_in_dbh_do} = 0;
74 This method is normally called by L<DBIx::Class::Schema/connection>, which
75 encapsulates its argument list in an arrayref before passing them here.
77 The argument list may contain:
83 The same 4-element argument set one would normally pass to
84 L<DBI/connect>, optionally followed by
85 L<extra attributes|/DBIx::Class specific connection attributes>
86 recognized by DBIx::Class:
88 $connect_info_args = [ $dsn, $user, $password, \%dbi_attributes?, \%extra_attributes? ];
92 A single code reference which returns a connected
93 L<DBI database handle|DBI/connect> optionally followed by
94 L<extra attributes|/DBIx::Class specific connection attributes> recognized
97 $connect_info_args = [ sub { DBI->connect (...) }, \%extra_attributes? ];
101 A single hashref with all the attributes and the dsn/user/password
104 $connect_info_args = [{
112 This is particularly useful for L<Catalyst> based applications, allowing the
113 following config (L<Config::General> style):
118 dsn dbi:mysql:database=test
127 Please note that the L<DBI> docs recommend that you always explicitly
128 set C<AutoCommit> to either I<0> or I<1>. L<DBIx::Class> further
129 recommends that it be set to I<1>, and that you perform transactions
130 via our L<DBIx::Class::Schema/txn_do> method. L<DBIx::Class> will set it
131 to I<1> if you do not do explicitly set it to zero. This is the default
132 for most DBDs. See L</DBIx::Class and AutoCommit> for details.
134 =head3 DBIx::Class specific connection attributes
136 In addition to the standard L<DBI|DBI/ATTRIBUTES_COMMON_TO_ALL_HANDLES>
137 L<connection|DBI/Database_Handle_Attributes> attributes, DBIx::Class recognizes
138 the following connection options. These options can be mixed in with your other
139 L<DBI> connection attributes, or placed in a seperate hashref
140 (C<\%extra_attributes>) as shown above.
142 Every time C<connect_info> is invoked, any previous settings for
143 these options will be cleared before setting the new ones, regardless of
144 whether any options are specified in the new C<connect_info>.
151 Specifies things to do immediately after connecting or re-connecting to
152 the database. Its value may contain:
158 This contains one SQL statement to execute.
160 =item an array reference
162 This contains SQL statements to execute in order. Each element contains
163 a string or a code reference that returns a string.
165 =item a code reference
167 This contains some code to execute. Unlike code references within an
168 array reference, its return value is ignored.
172 =item on_disconnect_do
174 Takes arguments in the same form as L</on_connect_do> and executes them
175 immediately before disconnecting from the database.
177 Note, this only runs if you explicitly call L</disconnect> on the
180 =item disable_sth_caching
182 If set to a true value, this option will disable the caching of
183 statement handles via L<DBI/prepare_cached>.
187 Sets the limit dialect. This is useful for JDBC-bridge among others
188 where the remote SQL-dialect cannot be determined by the name of the
189 driver alone. See also L<SQL::Abstract::Limit>.
193 Specifies what characters to use to quote table and column names. If
194 you use this you will want to specify L</name_sep> as well.
196 C<quote_char> expects either a single character, in which case is it
197 is placed on either side of the table/column name, or an arrayref of length
198 2 in which case the table/column name is placed between the elements.
200 For example under MySQL you should use C<< quote_char => '`' >>, and for
201 SQL Server you should use C<< quote_char => [qw/[ ]/] >>.
205 This only needs to be used in conjunction with C<quote_char>, and is used to
206 specify the charecter that seperates elements (schemas, tables, columns) from
207 each other. In most cases this is simply a C<.>.
209 The consequences of not supplying this value is that L<SQL::Abstract>
210 will assume DBIx::Class' uses of aliases to be complete column
211 names. The output will look like I<"me.name"> when it should actually
216 This Storage driver normally installs its own C<HandleError>, sets
217 C<RaiseError> and C<ShowErrorStatement> on, and sets C<PrintError> off on
218 all database handles, including those supplied by a coderef. It does this
219 so that it can have consistent and useful error behavior.
221 If you set this option to a true value, Storage will not do its usual
222 modifications to the database handle's attributes, and instead relies on
223 the settings in your connect_info DBI options (or the values you set in
224 your connection coderef, in the case that you are connecting via coderef).
226 Note that your custom settings can cause Storage to malfunction,
227 especially if you set a C<HandleError> handler that suppresses exceptions
228 and/or disable C<RaiseError>.
232 If this option is true, L<DBIx::Class> will use savepoints when nesting
233 transactions, making it possible to recover from failure in the inner
234 transaction without having to abort all outer transactions.
238 Use this argument to supply a cursor class other than the default
239 L<DBIx::Class::Storage::DBI::Cursor>.
243 Some real-life examples of arguments to L</connect_info> and
244 L<DBIx::Class::Schema/connect>
246 # Simple SQLite connection
247 ->connect_info([ 'dbi:SQLite:./foo.db' ]);
250 ->connect_info([ sub { DBI->connect(...) } ]);
252 # A bit more complicated
259 { quote_char => q{"}, name_sep => q{.} },
263 # Equivalent to the previous example
269 { AutoCommit => 1, quote_char => q{"}, name_sep => q{.} },
273 # Same, but with hashref as argument
274 # See parse_connect_info for explanation
277 dsn => 'dbi:Pg:dbname=foo',
279 password => 'my_pg_password',
286 # Subref + DBIx::Class-specific connection options
289 sub { DBI->connect(...) },
293 on_connect_do => ['SET search_path TO myschema,otherschema,public'],
294 disable_sth_caching => 1,
304 my ($self, $info_arg) = @_;
306 return $self->_connect_info if !$info_arg;
308 my @args = @$info_arg; # take a shallow copy for further mutilation
309 $self->_connect_info([@args]); # copy for _connect_info
312 # combine/pre-parse arguments depending on invocation style
315 if (ref $args[0] eq 'CODE') { # coderef with optional \%extra_attributes
316 %attrs = %{ $args[1] || {} };
319 elsif (ref $args[0] eq 'HASH') { # single hashref (i.e. Catalyst config)
320 %attrs = %{$args[0]};
322 for (qw/password user dsn/) {
323 unshift @args, delete $attrs{$_};
326 else { # otherwise assume dsn/user/password + \%attrs + \%extra_attrs
328 % { $args[3] || {} },
329 % { $args[4] || {} },
331 @args = @args[0,1,2];
334 # Kill sql_maker/_sql_maker_opts, so we get a fresh one with only
335 # the new set of options
336 $self->_sql_maker(undef);
337 $self->_sql_maker_opts({});
340 for my $storage_opt (@storage_options, 'cursor_class') { # @storage_options is declared at the top of the module
341 if(my $value = delete $attrs{$storage_opt}) {
342 $self->$storage_opt($value);
345 for my $sql_maker_opt (qw/limit_dialect quote_char name_sep/) {
346 if(my $opt_val = delete $attrs{$sql_maker_opt}) {
347 $self->_sql_maker_opts->{$sql_maker_opt} = $opt_val;
352 %attrs = () if (ref $args[0] eq 'CODE'); # _connect() never looks past $args[0] in this case
354 $self->_dbi_connect_info([@args, keys %attrs ? \%attrs : ()]);
355 $self->_connect_info;
360 This method is deprecated in favour of setting via L</connect_info>.
365 Arguments: ($subref | $method_name), @extra_coderef_args?
367 Execute the given $subref or $method_name using the new exception-based
368 connection management.
370 The first two arguments will be the storage object that C<dbh_do> was called
371 on and a database handle to use. Any additional arguments will be passed
372 verbatim to the called subref as arguments 2 and onwards.
374 Using this (instead of $self->_dbh or $self->dbh) ensures correct
375 exception handling and reconnection (or failover in future subclasses).
377 Your subref should have no side-effects outside of the database, as
378 there is the potential for your subref to be partially double-executed
379 if the database connection was stale/dysfunctional.
383 my @stuff = $schema->storage->dbh_do(
385 my ($storage, $dbh, @cols) = @_;
386 my $cols = join(q{, }, @cols);
387 $dbh->selectrow_array("SELECT $cols FROM foo");
398 my $dbh = $self->_dbh;
400 return $self->$code($dbh, @_) if $self->{_in_dbh_do}
401 || $self->{transaction_depth};
403 local $self->{_in_dbh_do} = 1;
406 my $want_array = wantarray;
409 $self->_verify_pid if $dbh;
411 $self->_populate_dbh;
416 @result = $self->$code($dbh, @_);
418 elsif(defined $want_array) {
419 $result[0] = $self->$code($dbh, @_);
422 $self->$code($dbh, @_);
427 if(!$exception) { return $want_array ? @result : $result[0] }
429 $self->throw_exception($exception) if $self->connected;
431 # We were not connected - reconnect and retry, but let any
432 # exception fall right through this time
433 $self->_populate_dbh;
434 $self->$code($self->_dbh, @_);
437 # This is basically a blend of dbh_do above and DBIx::Class::Storage::txn_do.
438 # It also informs dbh_do to bypass itself while under the direction of txn_do,
439 # via $self->{_in_dbh_do} (this saves some redundant eval and errorcheck, etc)
444 ref $coderef eq 'CODE' or $self->throw_exception
445 ('$coderef must be a CODE reference');
447 return $coderef->(@_) if $self->{transaction_depth} && ! $self->auto_savepoint;
449 local $self->{_in_dbh_do} = 1;
452 my $want_array = wantarray;
457 $self->_verify_pid if $self->_dbh;
458 $self->_populate_dbh if !$self->_dbh;
462 @result = $coderef->(@_);
464 elsif(defined $want_array) {
465 $result[0] = $coderef->(@_);
474 if(!$exception) { return $want_array ? @result : $result[0] }
476 if($tried++ > 0 || $self->connected) {
477 eval { $self->txn_rollback };
478 my $rollback_exception = $@;
479 if($rollback_exception) {
480 my $exception_class = "DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION";
481 $self->throw_exception($exception) # propagate nested rollback
482 if $rollback_exception =~ /$exception_class/;
484 $self->throw_exception(
485 "Transaction aborted: ${exception}. "
486 . "Rollback failed: ${rollback_exception}"
489 $self->throw_exception($exception)
492 # We were not connected, and was first try - reconnect and retry
494 $self->_populate_dbh;
500 Our C<disconnect> method also performs a rollback first if the
501 database is not in C<AutoCommit> mode.
508 if( $self->connected ) {
509 my $connection_do = $self->on_disconnect_do;
510 $self->_do_connection_actions($connection_do) if ref($connection_do);
512 $self->_dbh->rollback unless $self->_dbh_autocommit;
513 $self->_dbh->disconnect;
519 =head2 with_deferred_fk_checks
523 =item Arguments: C<$coderef>
525 =item Return Value: The return value of $coderef
529 Storage specific method to run the code ref with FK checks deferred or
530 in MySQL's case disabled entirely.
534 # Storage subclasses should override this
535 sub with_deferred_fk_checks {
536 my ($self, $sub) = @_;
544 if(my $dbh = $self->_dbh) {
545 if(defined $self->_conn_tid && $self->_conn_tid != threads->tid) {
552 return 0 if !$self->_dbh;
554 return ($dbh->FETCH('Active') && $dbh->ping);
560 # handle pid changes correctly
561 # NOTE: assumes $self->_dbh is a valid $dbh
565 return if defined $self->_conn_pid && $self->_conn_pid == $$;
567 $self->_dbh->{InactiveDestroy} = 1;
574 sub ensure_connected {
577 unless ($self->connected) {
578 $self->_populate_dbh;
584 Returns the dbh - a data base handle of class L<DBI>.
591 $self->ensure_connected;
595 sub _sql_maker_args {
598 return ( bindtype=>'columns', array_datatypes => 1, limit_dialect => $self->dbh, %{$self->_sql_maker_opts} );
603 unless ($self->_sql_maker) {
604 my $sql_maker_class = $self->sql_maker_class;
605 $self->ensure_class_loaded ($sql_maker_class);
606 $self->_sql_maker($sql_maker_class->new( $self->_sql_maker_args ));
608 return $self->_sql_maker;
615 my @info = @{$self->_dbi_connect_info || []};
616 $self->_dbh($self->_connect(@info));
618 $self->_conn_pid($$);
619 $self->_conn_tid(threads->tid) if $INC{'threads.pm'};
621 $self->_determine_driver;
623 # Always set the transaction depth on connect, since
624 # there is no transaction in progress by definition
625 $self->{transaction_depth} = $self->_dbh_autocommit ? 0 : 1;
627 my $connection_do = $self->on_connect_do;
628 $self->_do_connection_actions($connection_do) if $connection_do;
631 sub _determine_driver {
634 if (ref $self eq 'DBIx::Class::Storage::DBI') {
637 if ($self->_dbh) { # we are connected
638 $driver = $self->_dbh->{Driver}{Name};
640 # try to use dsn to not require being connected, the driver may still
641 # force a connection in _rebless to determine version
642 ($driver) = $self->_dbi_connect_info->[0] =~ /dbi:([^:]+):/i;
645 if ($self->load_optional_class("DBIx::Class::Storage::DBI::${driver}")) {
646 bless $self, "DBIx::Class::Storage::DBI::${driver}";
652 sub _do_connection_actions {
654 my $connection_do = shift;
656 if (!ref $connection_do) {
657 $self->_do_query($connection_do);
659 elsif (ref $connection_do eq 'ARRAY') {
660 $self->_do_query($_) foreach @$connection_do;
662 elsif (ref $connection_do eq 'CODE') {
663 $connection_do->($self);
666 $self->throw_exception (sprintf ("Don't know how to process conection actions of type '%s'", ref $connection_do) );
673 my ($self, $action) = @_;
675 if (ref $action eq 'CODE') {
676 $action = $action->($self);
677 $self->_do_query($_) foreach @$action;
680 # Most debuggers expect ($sql, @bind), so we need to exclude
681 # the attribute hash which is the second argument to $dbh->do
682 # furthermore the bind values are usually to be presented
683 # as named arrayref pairs, so wrap those here too
684 my @do_args = (ref $action eq 'ARRAY') ? (@$action) : ($action);
685 my $sql = shift @do_args;
686 my $attrs = shift @do_args;
687 my @bind = map { [ undef, $_ ] } @do_args;
689 $self->_query_start($sql, @bind);
690 $self->_dbh->do($sql, $attrs, @do_args);
691 $self->_query_end($sql, @bind);
698 my ($self, @info) = @_;
700 $self->throw_exception("You failed to provide any connection info")
703 my ($old_connect_via, $dbh);
705 if ($INC{'Apache/DBI.pm'} && $ENV{MOD_PERL}) {
706 $old_connect_via = $DBI::connect_via;
707 $DBI::connect_via = 'connect';
711 if(ref $info[0] eq 'CODE') {
715 $dbh = DBI->connect(@info);
718 if($dbh && !$self->unsafe) {
719 my $weak_self = $self;
720 Scalar::Util::weaken($weak_self);
721 $dbh->{HandleError} = sub {
723 $weak_self->throw_exception("DBI Exception: $_[0]");
726 croak ("DBI Exception: $_[0]");
729 $dbh->{ShowErrorStatement} = 1;
730 $dbh->{RaiseError} = 1;
731 $dbh->{PrintError} = 0;
735 $DBI::connect_via = $old_connect_via if $old_connect_via;
737 $self->throw_exception("DBI Connection failed: " . ($@||$DBI::errstr))
740 $self->_dbh_autocommit($dbh->{AutoCommit});
746 my ($self, $name) = @_;
748 $name = $self->_svp_generate_name
749 unless defined $name;
751 $self->throw_exception ("You can't use savepoints outside a transaction")
752 if $self->{transaction_depth} == 0;
754 $self->throw_exception ("Your Storage implementation doesn't support savepoints")
755 unless $self->can('_svp_begin');
757 push @{ $self->{savepoints} }, $name;
759 $self->debugobj->svp_begin($name) if $self->debug;
761 return $self->_svp_begin($name);
765 my ($self, $name) = @_;
767 $self->throw_exception ("You can't use savepoints outside a transaction")
768 if $self->{transaction_depth} == 0;
770 $self->throw_exception ("Your Storage implementation doesn't support savepoints")
771 unless $self->can('_svp_release');
774 $self->throw_exception ("Savepoint '$name' does not exist")
775 unless grep { $_ eq $name } @{ $self->{savepoints} };
777 # Dig through the stack until we find the one we are releasing. This keeps
778 # the stack up to date.
781 do { $svp = pop @{ $self->{savepoints} } } while $svp ne $name;
783 $name = pop @{ $self->{savepoints} };
786 $self->debugobj->svp_release($name) if $self->debug;
788 return $self->_svp_release($name);
792 my ($self, $name) = @_;
794 $self->throw_exception ("You can't use savepoints outside a transaction")
795 if $self->{transaction_depth} == 0;
797 $self->throw_exception ("Your Storage implementation doesn't support savepoints")
798 unless $self->can('_svp_rollback');
801 # If they passed us a name, verify that it exists in the stack
802 unless(grep({ $_ eq $name } @{ $self->{savepoints} })) {
803 $self->throw_exception("Savepoint '$name' does not exist!");
806 # Dig through the stack until we find the one we are releasing. This keeps
807 # the stack up to date.
808 while(my $s = pop(@{ $self->{savepoints} })) {
809 last if($s eq $name);
811 # Add the savepoint back to the stack, as a rollback doesn't remove the
812 # named savepoint, only everything after it.
813 push(@{ $self->{savepoints} }, $name);
815 # We'll assume they want to rollback to the last savepoint
816 $name = $self->{savepoints}->[-1];
819 $self->debugobj->svp_rollback($name) if $self->debug;
821 return $self->_svp_rollback($name);
824 sub _svp_generate_name {
827 return 'savepoint_'.scalar(@{ $self->{'savepoints'} });
832 $self->ensure_connected();
833 if($self->{transaction_depth} == 0) {
834 $self->debugobj->txn_begin()
836 # this isn't ->_dbh-> because
837 # we should reconnect on begin_work
838 # for AutoCommit users
839 $self->dbh->begin_work;
840 } elsif ($self->auto_savepoint) {
843 $self->{transaction_depth}++;
848 if ($self->{transaction_depth} == 1) {
849 my $dbh = $self->_dbh;
850 $self->debugobj->txn_commit()
853 $self->{transaction_depth} = 0
854 if $self->_dbh_autocommit;
856 elsif($self->{transaction_depth} > 1) {
857 $self->{transaction_depth}--;
859 if $self->auto_savepoint;
865 my $dbh = $self->_dbh;
867 if ($self->{transaction_depth} == 1) {
868 $self->debugobj->txn_rollback()
870 $self->{transaction_depth} = 0
871 if $self->_dbh_autocommit;
874 elsif($self->{transaction_depth} > 1) {
875 $self->{transaction_depth}--;
876 if ($self->auto_savepoint) {
882 die DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION->new;
887 my $exception_class = "DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION";
888 $error =~ /$exception_class/ and $self->throw_exception($error);
889 # ensure that a failed rollback resets the transaction depth
890 $self->{transaction_depth} = $self->_dbh_autocommit ? 0 : 1;
891 $self->throw_exception($error);
895 # This used to be the top-half of _execute. It was split out to make it
896 # easier to override in NoBindVars without duping the rest. It takes up
897 # all of _execute's args, and emits $sql, @bind.
898 sub _prep_for_execute {
899 my ($self, $op, $extra_bind, $ident, $args) = @_;
901 if( Scalar::Util::blessed($ident) && $ident->isa("DBIx::Class::ResultSource") ) {
902 $ident = $ident->from();
905 my ($sql, @bind) = $self->sql_maker->$op($ident, @$args);
908 map { ref $_ eq 'ARRAY' ? $_ : [ '!!dummy', $_ ] } @$extra_bind)
910 return ($sql, \@bind);
917 =item Arguments: $rs_attrs
919 =item Return Value: \[ $sql, @bind ]
923 Returns the SQL statement and bind vars that would result from the given
924 ResultSet attributes (does not actually run a query)
929 my ($self, $rs_attr) = @_;
931 my $sql_maker = $self->sql_maker;
932 local $sql_maker->{for};
934 # my ($op, $bind, $ident, $bind_attrs, $select, $cond, $order, $rows, $offset) = $self->_select_args(...);
935 my @args = $self->_select_args($rs_attr->{from}, $rs_attr->{select}, $rs_attr->{where}, $rs_attr);
937 # my ($sql, $bind) = $self->_prep_for_execute($op, $bind, $ident, [ $select, $cond, $order, $rows, $offset ]);
938 my ($sql, $bind) = $self->_prep_for_execute(
940 [ @args[4 .. $#args] ],
942 return \[ "($sql)", @{ $bind || [] }];
945 sub _fix_bind_params {
946 my ($self, @bind) = @_;
948 ### Turn @bind from something like this:
949 ### ( [ "artist", 1 ], [ "cdid", 1, 3 ] )
951 ### ( "'1'", "'1'", "'3'" )
954 if ( defined( $_ && $_->[1] ) ) {
955 map { qq{'$_'}; } @{$_}[ 1 .. $#$_ ];
962 my ( $self, $sql, @bind ) = @_;
964 if ( $self->debug ) {
965 @bind = $self->_fix_bind_params(@bind);
967 $self->debugobj->query_start( $sql, @bind );
972 my ( $self, $sql, @bind ) = @_;
974 if ( $self->debug ) {
975 @bind = $self->_fix_bind_params(@bind);
976 $self->debugobj->query_end( $sql, @bind );
981 my ($self, $dbh, $op, $extra_bind, $ident, $bind_attributes, @args) = @_;
983 my ($sql, $bind) = $self->_prep_for_execute($op, $extra_bind, $ident, \@args);
985 $self->_query_start( $sql, @$bind );
987 my $sth = $self->sth($sql,$op);
989 my $placeholder_index = 1;
991 foreach my $bound (@$bind) {
993 my($column_name, @data) = @$bound;
995 if ($bind_attributes) {
996 $attributes = $bind_attributes->{$column_name}
997 if defined $bind_attributes->{$column_name};
1000 foreach my $data (@data) {
1001 my $ref = ref $data;
1002 $data = $ref && $ref ne 'ARRAY' ? ''.$data : $data; # stringify args (except arrayrefs)
1004 $sth->bind_param($placeholder_index, $data, $attributes);
1005 $placeholder_index++;
1009 # Can this fail without throwing an exception anyways???
1010 my $rv = $sth->execute();
1011 $self->throw_exception($sth->errstr) if !$rv;
1013 $self->_query_end( $sql, @$bind );
1015 return (wantarray ? ($rv, $sth, @$bind) : $rv);
1020 $self->dbh_do('_dbh_execute', @_)
1024 my ($self, $source, $to_insert) = @_;
1026 my $ident = $source->from;
1027 my $bind_attributes = $self->source_bind_attributes($source);
1029 my $updated_cols = {};
1031 $self->ensure_connected;
1032 foreach my $col ( $source->columns ) {
1033 if ( !defined $to_insert->{$col} ) {
1034 my $col_info = $source->column_info($col);
1036 if ( $col_info->{auto_nextval} ) {
1037 $updated_cols->{$col} = $to_insert->{$col} = $self->_sequence_fetch( 'nextval', $col_info->{sequence} || $self->_dbh_get_autoinc_seq($self->dbh, $source) );
1042 $self->_execute('insert' => [], $source, $bind_attributes, $to_insert);
1044 return $updated_cols;
1047 ## Still not quite perfect, and EXPERIMENTAL
1048 ## Currently it is assumed that all values passed will be "normal", i.e. not
1049 ## scalar refs, or at least, all the same type as the first set, the statement is
1050 ## only prepped once.
1052 my ($self, $source, $cols, $data) = @_;
1054 my $table = $source->from;
1055 @colvalues{@$cols} = (0..$#$cols);
1056 my ($sql, @bind) = $self->sql_maker->insert($table, \%colvalues);
1058 $self->_query_start( $sql, @bind );
1059 my $sth = $self->sth($sql);
1061 # @bind = map { ref $_ ? ''.$_ : $_ } @bind; # stringify args
1063 ## This must be an arrayref, else nothing works!
1064 my $tuple_status = [];
1066 ## Get the bind_attributes, if any exist
1067 my $bind_attributes = $self->source_bind_attributes($source);
1069 ## Bind the values and execute
1070 my $placeholder_index = 1;
1072 foreach my $bound (@bind) {
1074 my $attributes = {};
1075 my ($column_name, $data_index) = @$bound;
1077 if( $bind_attributes ) {
1078 $attributes = $bind_attributes->{$column_name}
1079 if defined $bind_attributes->{$column_name};
1082 my @data = map { $_->[$data_index] } @$data;
1084 $sth->bind_param_array( $placeholder_index, [@data], $attributes );
1085 $placeholder_index++;
1087 my $rv = eval { $sth->execute_array({ArrayTupleStatus => $tuple_status}) };
1090 ++$i while $i <= $#$tuple_status && !ref $tuple_status->[$i];
1092 $self->throw_exception($sth->errstr || "Unexpected populate error: $err")
1093 if ($i > $#$tuple_status);
1095 require Data::Dumper;
1096 local $Data::Dumper::Terse = 1;
1097 local $Data::Dumper::Indent = 1;
1098 local $Data::Dumper::Useqq = 1;
1099 local $Data::Dumper::Quotekeys = 0;
1101 $self->throw_exception(sprintf "%s for populate slice:\n%s",
1102 $tuple_status->[$i][1],
1103 Data::Dumper::Dumper(
1104 { map { $cols->[$_] => $data->[$i][$_] } (0 .. $#$cols) }
1108 $self->throw_exception($sth->errstr) if !$rv;
1110 $self->_query_end( $sql, @bind );
1111 return (wantarray ? ($rv, $sth, @bind) : $rv);
1115 my $self = shift @_;
1116 my $source = shift @_;
1117 my $bind_attributes = $self->source_bind_attributes($source);
1119 return $self->_execute('update' => [], $source, $bind_attributes, @_);
1124 my $self = shift @_;
1125 my $source = shift @_;
1127 my $bind_attrs = $self->source_bind_attributes($source);
1129 return $self->_execute('delete' => [], $source, $bind_attrs, @_);
1132 # We were sent here because the $rs contains a complex search
1133 # which will require a subquery to select the correct rows
1134 # (i.e. joined or limited resultsets)
1136 # Genarating a single PK column subquery is trivial and supported
1137 # by all RDBMS. However if we have a multicolumn PK, things get ugly.
1138 # Look at _multipk_update_delete()
1139 sub _subq_update_delete {
1141 my ($rs, $op, $values) = @_;
1143 my $rsrc = $rs->result_source;
1145 # we already check this, but double check naively just in case. Should be removed soon
1146 my $sel = $rs->_resolved_attrs->{select};
1147 $sel = [ $sel ] unless ref $sel eq 'ARRAY';
1148 my @pcols = $rsrc->primary_columns;
1149 if (@$sel != @pcols) {
1150 $self->throw_exception (
1151 'Subquery update/delete can not be called on resultsets selecting a'
1152 .' number of columns different than the number of primary keys'
1159 $op eq 'update' ? $values : (),
1160 { $pcols[0] => { -in => $rs->as_query } },
1165 return $self->_multipk_update_delete (@_);
1169 # ANSI SQL does not provide a reliable way to perform a multicol-PK
1170 # resultset update/delete involving subqueries. So by default resort
1171 # to simple (and inefficient) delete_all style per-row opearations,
1172 # while allowing specific storages to override this with a faster
1175 sub _multipk_update_delete {
1176 return shift->_per_row_update_delete (@_);
1179 # This is the default loop used to delete/update rows for multi PK
1180 # resultsets, and used by mysql exclusively (because it can't do anything
1183 # We do not use $row->$op style queries, because resultset update/delete
1184 # is not expected to cascade (this is what delete_all/update_all is for).
1186 # There should be no race conditions as the entire operation is rolled
1189 sub _per_row_update_delete {
1191 my ($rs, $op, $values) = @_;
1193 my $rsrc = $rs->result_source;
1194 my @pcols = $rsrc->primary_columns;
1196 my $guard = $self->txn_scope_guard;
1198 # emulate the return value of $sth->execute for non-selects
1199 my $row_cnt = '0E0';
1201 my $subrs_cur = $rs->cursor;
1202 while (my @pks = $subrs_cur->next) {
1205 for my $i (0.. $#pcols) {
1206 $cond->{$pcols[$i]} = $pks[$i];
1211 $op eq 'update' ? $values : (),
1225 my $sql_maker = $self->sql_maker;
1226 local $sql_maker->{for};
1227 return $self->_execute($self->_select_args(@_));
1231 my ($self, $ident, $select, $condition, $attrs) = @_;
1233 my $for = delete $attrs->{for};
1234 my $sql_maker = $self->sql_maker;
1235 $sql_maker->{for} = $for;
1238 { $attrs->{$_} ? ( $_ => $attrs->{$_} ) : () }
1239 (qw/order_by group_by having _virtual_order_by/ )
1243 my $bind_attrs = {};
1245 my $alias2source = $self->_resolve_ident_sources ($ident);
1247 for my $alias (keys %$alias2source) {
1248 my $bindtypes = $self->source_bind_attributes ($alias2source->{$alias}) || {};
1249 for my $col (keys %$bindtypes) {
1251 my $fqcn = join ('.', $alias, $col);
1252 $bind_attrs->{$fqcn} = $bindtypes->{$col} if $bindtypes->{$col};
1254 # so that unqualified searches can be bound too
1255 $bind_attrs->{$col} = $bind_attrs->{$fqcn} if $alias eq 'me';
1259 # This would be the point to deflate anything found in $condition
1260 # (and leave $attrs->{bind} intact). Problem is - inflators historically
1261 # expect a row object. And all we have is a resultsource (it is trivial
1262 # to extract deflator coderefs via $alias2source above).
1264 # I don't see a way forward other than changing the way deflators are
1265 # invoked, and that's just bad...
1267 my @args = ('select', $attrs->{bind}, $ident, $bind_attrs, $select, $condition, $order);
1268 if ($attrs->{software_limit} ||
1269 $sql_maker->_default_limit_syntax eq "GenericSubQ") {
1270 $attrs->{software_limit} = 1;
1272 $self->throw_exception("rows attribute must be positive if present")
1273 if (defined($attrs->{rows}) && !($attrs->{rows} > 0));
1275 # MySQL actually recommends this approach. I cringe.
1276 $attrs->{rows} = 2**48 if not defined $attrs->{rows} and defined $attrs->{offset};
1277 push @args, $attrs->{rows}, $attrs->{offset};
1282 sub _resolve_ident_sources {
1283 my ($self, $ident) = @_;
1285 my $alias2source = {};
1287 # the reason this is so contrived is that $ident may be a {from}
1288 # structure, specifying multiple tables to join
1289 if ( Scalar::Util::blessed($ident) && $ident->isa("DBIx::Class::ResultSource") ) {
1290 # this is compat mode for insert/update/delete which do not deal with aliases
1291 $alias2source->{me} = $ident;
1293 elsif (ref $ident eq 'ARRAY') {
1297 if (ref $_ eq 'HASH') {
1300 if (ref $_ eq 'ARRAY' and ref $_->[0] eq 'HASH') {
1304 $alias2source->{$tabinfo->{-alias}} = $tabinfo->{-result_source}
1305 if ($tabinfo->{-result_source});
1309 return $alias2source;
1313 my ($self, $source, $attrs) = @_;
1315 my $tmp_attrs = { %$attrs };
1317 # take off any pagers, record_filter is cdbi, and no point of ordering a count
1318 delete $tmp_attrs->{$_} for (qw/select as rows offset page order_by record_filter/);
1320 # overwrite the selector
1321 $tmp_attrs->{select} = { count => '*' };
1323 my $tmp_rs = $source->resultset_class->new($source, $tmp_attrs);
1324 my ($count) = $tmp_rs->cursor->next;
1326 # if the offset/rows attributes are still present, we did not use
1327 # a subquery, so we need to make the calculations in software
1328 $count -= $attrs->{offset} if $attrs->{offset};
1329 $count = $attrs->{rows} if $attrs->{rows} and $attrs->{rows} < $count;
1330 $count = 0 if ($count < 0);
1336 my ($self, $source, $attrs) = @_;
1338 # copy for the subquery, we need to do some adjustments to it too
1339 my $sub_attrs = { %$attrs };
1341 # these can not go in the subquery, and there is no point of ordering it
1342 delete $sub_attrs->{$_} for qw/prefetch collapse select as order_by/;
1344 # if we prefetch, we group_by primary keys only as this is what we would get out of the rs via ->next/->all
1345 # simply deleting group_by suffices, as the code below will re-fill it
1346 # Note: we check $attrs, as $sub_attrs has collapse deleted
1347 if (ref $attrs->{collapse} and keys %{$attrs->{collapse}} ) {
1348 delete $sub_attrs->{group_by};
1351 $sub_attrs->{group_by} ||= [ map { "$attrs->{alias}.$_" } ($source->primary_columns) ];
1352 $sub_attrs->{select} = $self->_grouped_count_select ($source, $sub_attrs);
1355 count_subq => $source->resultset_class->new ($source, $sub_attrs )->as_query
1358 # the subquery replaces this
1359 delete $attrs->{$_} for qw/where bind prefetch collapse group_by having having_bind rows offset page pager/;
1361 return $self->count ($source, $attrs);
1365 # Returns a SELECT to go with a supplied GROUP BY
1366 # (caled by count_grouped so a group_by is present)
1367 # Most databases expect them to match, but some
1368 # choke in various ways.
1370 sub _grouped_count_select {
1371 my ($self, $source, $rs_args) = @_;
1372 return $rs_args->{group_by};
1375 sub source_bind_attributes {
1376 my ($self, $source) = @_;
1378 my $bind_attributes;
1379 foreach my $column ($source->columns) {
1381 my $data_type = $source->column_info($column)->{data_type} || '';
1382 $bind_attributes->{$column} = $self->bind_attribute_by_data_type($data_type)
1386 return $bind_attributes;
1393 =item Arguments: $ident, $select, $condition, $attrs
1397 Handle a SQL select statement.
1403 my ($ident, $select, $condition, $attrs) = @_;
1404 return $self->cursor_class->new($self, \@_, $attrs);
1409 my ($rv, $sth, @bind) = $self->_select(@_);
1410 my @row = $sth->fetchrow_array;
1411 my @nextrow = $sth->fetchrow_array if @row;
1412 if(@row && @nextrow) {
1413 carp "Query returned more than one row. SQL that returns multiple rows is DEPRECATED for ->find and ->single";
1415 # Need to call finish() to work round broken DBDs
1424 =item Arguments: $sql
1428 Returns a L<DBI> sth (statement handle) for the supplied SQL.
1433 my ($self, $dbh, $sql) = @_;
1435 # 3 is the if_active parameter which avoids active sth re-use
1436 my $sth = $self->disable_sth_caching
1437 ? $dbh->prepare($sql)
1438 : $dbh->prepare_cached($sql, {}, 3);
1440 # XXX You would think RaiseError would make this impossible,
1441 # but apparently that's not true :(
1442 $self->throw_exception($dbh->errstr) if !$sth;
1448 my ($self, $sql) = @_;
1449 $self->dbh_do('_dbh_sth', $sql);
1452 sub _dbh_columns_info_for {
1453 my ($self, $dbh, $table) = @_;
1455 if ($dbh->can('column_info')) {
1458 my ($schema,$tab) = $table =~ /^(.+?)\.(.+)$/ ? ($1,$2) : (undef,$table);
1459 my $sth = $dbh->column_info( undef,$schema, $tab, '%' );
1461 while ( my $info = $sth->fetchrow_hashref() ){
1463 $column_info{data_type} = $info->{TYPE_NAME};
1464 $column_info{size} = $info->{COLUMN_SIZE};
1465 $column_info{is_nullable} = $info->{NULLABLE} ? 1 : 0;
1466 $column_info{default_value} = $info->{COLUMN_DEF};
1467 my $col_name = $info->{COLUMN_NAME};
1468 $col_name =~ s/^\"(.*)\"$/$1/;
1470 $result{$col_name} = \%column_info;
1473 return \%result if !$@ && scalar keys %result;
1477 my $sth = $dbh->prepare($self->sql_maker->select($table, undef, \'1 = 0'));
1479 my @columns = @{$sth->{NAME_lc}};
1480 for my $i ( 0 .. $#columns ){
1482 $column_info{data_type} = $sth->{TYPE}->[$i];
1483 $column_info{size} = $sth->{PRECISION}->[$i];
1484 $column_info{is_nullable} = $sth->{NULLABLE}->[$i] ? 1 : 0;
1486 if ($column_info{data_type} =~ m/^(.*?)\((.*?)\)$/) {
1487 $column_info{data_type} = $1;
1488 $column_info{size} = $2;
1491 $result{$columns[$i]} = \%column_info;
1495 foreach my $col (keys %result) {
1496 my $colinfo = $result{$col};
1497 my $type_num = $colinfo->{data_type};
1499 if(defined $type_num && $dbh->can('type_info')) {
1500 my $type_info = $dbh->type_info($type_num);
1501 $type_name = $type_info->{TYPE_NAME} if $type_info;
1502 $colinfo->{data_type} = $type_name if $type_name;
1509 sub columns_info_for {
1510 my ($self, $table) = @_;
1511 $self->dbh_do('_dbh_columns_info_for', $table);
1514 =head2 last_insert_id
1516 Return the row id of the last insert.
1520 sub _dbh_last_insert_id {
1521 # All Storage's need to register their own _dbh_last_insert_id
1522 # the old SQLite-based method was highly inappropriate
1525 my $class = ref $self;
1526 $self->throw_exception (<<EOE);
1528 No _dbh_last_insert_id() method found in $class.
1529 Since the method of obtaining the autoincrement id of the last insert
1530 operation varies greatly between different databases, this method must be
1531 individually implemented for every storage class.
1535 sub last_insert_id {
1537 $self->dbh_do('_dbh_last_insert_id', @_);
1542 Returns the database driver name.
1546 sub sqlt_type { shift->dbh->{Driver}->{Name} }
1548 =head2 bind_attribute_by_data_type
1550 Given a datatype from column info, returns a database specific bind
1551 attribute for C<< $dbh->bind_param($val,$attribute) >> or nothing if we will
1552 let the database planner just handle it.
1554 Generally only needed for special case column types, like bytea in postgres.
1558 sub bind_attribute_by_data_type {
1562 =head2 create_ddl_dir (EXPERIMENTAL)
1566 =item Arguments: $schema \@databases, $version, $directory, $preversion, \%sqlt_args
1570 Creates a SQL file based on the Schema, for each of the specified
1571 database engines in C<\@databases> in the given directory.
1572 (note: specify L<SQL::Translator> names, not L<DBI> driver names).
1574 Given a previous version number, this will also create a file containing
1575 the ALTER TABLE statements to transform the previous schema into the
1576 current one. Note that these statements may contain C<DROP TABLE> or
1577 C<DROP COLUMN> statements that can potentially destroy data.
1579 The file names are created using the C<ddl_filename> method below, please
1580 override this method in your schema if you would like a different file
1581 name format. For the ALTER file, the same format is used, replacing
1582 $version in the name with "$preversion-$version".
1584 See L<SQL::Translator/METHODS> for a list of values for C<\%sqlt_args>.
1585 The most common value for this would be C<< { add_drop_table => 1 } >>
1586 to have the SQL produced include a C<DROP TABLE> statement for each table
1587 created. For quoting purposes supply C<quote_table_names> and
1588 C<quote_field_names>.
1590 If no arguments are passed, then the following default values are assumed:
1594 =item databases - ['MySQL', 'SQLite', 'PostgreSQL']
1596 =item version - $schema->schema_version
1598 =item directory - './'
1600 =item preversion - <none>
1604 By default, C<\%sqlt_args> will have
1606 { add_drop_table => 1, ignore_constraint_names => 1, ignore_index_names => 1 }
1608 merged with the hash passed in. To disable any of those features, pass in a
1609 hashref like the following
1611 { ignore_constraint_names => 0, # ... other options }
1614 Note that this feature is currently EXPERIMENTAL and may not work correctly
1615 across all databases, or fully handle complex relationships.
1617 WARNING: Please check all SQL files created, before applying them.
1621 sub create_ddl_dir {
1622 my ($self, $schema, $databases, $version, $dir, $preversion, $sqltargs) = @_;
1624 if(!$dir || !-d $dir) {
1625 carp "No directory given, using ./\n";
1628 $databases ||= ['MySQL', 'SQLite', 'PostgreSQL'];
1629 $databases = [ $databases ] if(ref($databases) ne 'ARRAY');
1631 my $schema_version = $schema->schema_version || '1.x';
1632 $version ||= $schema_version;
1635 add_drop_table => 1,
1636 ignore_constraint_names => 1,
1637 ignore_index_names => 1,
1641 $self->throw_exception(q{Can't create a ddl file without SQL::Translator 0.09003: '}
1642 . $self->_check_sqlt_message . q{'})
1643 if !$self->_check_sqlt_version;
1645 my $sqlt = SQL::Translator->new( $sqltargs );
1647 $sqlt->parser('SQL::Translator::Parser::DBIx::Class');
1648 my $sqlt_schema = $sqlt->translate({ data => $schema })
1649 or $self->throw_exception ($sqlt->error);
1651 foreach my $db (@$databases) {
1653 $sqlt->{schema} = $sqlt_schema;
1654 $sqlt->producer($db);
1657 my $filename = $schema->ddl_filename($db, $version, $dir);
1658 if (-e $filename && ($version eq $schema_version )) {
1659 # if we are dumping the current version, overwrite the DDL
1660 carp "Overwriting existing DDL file - $filename";
1664 my $output = $sqlt->translate;
1666 carp("Failed to translate to $db, skipping. (" . $sqlt->error . ")");
1669 if(!open($file, ">$filename")) {
1670 $self->throw_exception("Can't open $filename for writing ($!)");
1673 print $file $output;
1676 next unless ($preversion);
1678 require SQL::Translator::Diff;
1680 my $prefilename = $schema->ddl_filename($db, $preversion, $dir);
1681 if(!-e $prefilename) {
1682 carp("No previous schema file found ($prefilename)");
1686 my $difffile = $schema->ddl_filename($db, $version, $dir, $preversion);
1688 carp("Overwriting existing diff file - $difffile");
1694 my $t = SQL::Translator->new($sqltargs);
1699 or $self->throw_exception ($t->error);
1701 my $out = $t->translate( $prefilename )
1702 or $self->throw_exception ($t->error);
1704 $source_schema = $t->schema;
1706 $source_schema->name( $prefilename )
1707 unless ( $source_schema->name );
1710 # The "new" style of producers have sane normalization and can support
1711 # diffing a SQL file against a DBIC->SQLT schema. Old style ones don't
1712 # And we have to diff parsed SQL against parsed SQL.
1713 my $dest_schema = $sqlt_schema;
1715 unless ( "SQL::Translator::Producer::$db"->can('preprocess_schema') ) {
1716 my $t = SQL::Translator->new($sqltargs);
1721 or $self->throw_exception ($t->error);
1723 my $out = $t->translate( $filename )
1724 or $self->throw_exception ($t->error);
1726 $dest_schema = $t->schema;
1728 $dest_schema->name( $filename )
1729 unless $dest_schema->name;
1732 my $diff = SQL::Translator::Diff::schema_diff($source_schema, $db,
1736 if(!open $file, ">$difffile") {
1737 $self->throw_exception("Can't write to $difffile ($!)");
1745 =head2 deployment_statements
1749 =item Arguments: $schema, $type, $version, $directory, $sqlt_args
1753 Returns the statements used by L</deploy> and L<DBIx::Class::Schema/deploy>.
1755 The L<SQL::Translator> (not L<DBI>) database driver name can be explicitly
1756 provided in C<$type>, otherwise the result of L</sqlt_type> is used as default.
1758 C<$directory> is used to return statements from files in a previously created
1759 L</create_ddl_dir> directory and is optional. The filenames are constructed
1760 from L<DBIx::Class::Schema/ddl_filename>, the schema name and the C<$version>.
1762 If no C<$directory> is specified then the statements are constructed on the
1763 fly using L<SQL::Translator> and C<$version> is ignored.
1765 See L<SQL::Translator/METHODS> for a list of values for C<$sqlt_args>.
1769 sub deployment_statements {
1770 my ($self, $schema, $type, $version, $dir, $sqltargs) = @_;
1771 # Need to be connected to get the correct sqlt_type
1772 $self->ensure_connected() unless $type;
1773 $type ||= $self->sqlt_type;
1774 $version ||= $schema->schema_version || '1.x';
1776 my $filename = $schema->ddl_filename($type, $version, $dir);
1780 open($file, "<$filename")
1781 or $self->throw_exception("Can't open $filename ($!)");
1784 return join('', @rows);
1787 $self->throw_exception(q{Can't deploy without SQL::Translator 0.09003: '}
1788 . $self->_check_sqlt_message . q{'})
1789 if !$self->_check_sqlt_version;
1791 require SQL::Translator::Parser::DBIx::Class;
1792 eval qq{use SQL::Translator::Producer::${type}};
1793 $self->throw_exception($@) if $@;
1795 # sources needs to be a parser arg, but for simplicty allow at top level
1797 $sqltargs->{parser_args}{sources} = delete $sqltargs->{sources}
1798 if exists $sqltargs->{sources};
1800 my $tr = SQL::Translator->new(%$sqltargs);
1801 SQL::Translator::Parser::DBIx::Class::parse( $tr, $schema );
1802 return "SQL::Translator::Producer::${type}"->can('produce')->($tr);
1806 my ($self, $schema, $type, $sqltargs, $dir) = @_;
1809 return if($line =~ /^--/);
1811 # next if($line =~ /^DROP/m);
1812 return if($line =~ /^BEGIN TRANSACTION/m);
1813 return if($line =~ /^COMMIT/m);
1814 return if $line =~ /^\s+$/; # skip whitespace only
1815 $self->_query_start($line);
1817 $self->dbh->do($line); # shouldn't be using ->dbh ?
1820 carp qq{$@ (running "${line}")};
1822 $self->_query_end($line);
1824 my @statements = $self->deployment_statements($schema, $type, undef, $dir, { %{ $sqltargs || {} }, no_comments => 1 } );
1825 if (@statements > 1) {
1826 foreach my $statement (@statements) {
1827 $deploy->( $statement );
1830 elsif (@statements == 1) {
1831 foreach my $line ( split(";\n", $statements[0])) {
1837 =head2 datetime_parser
1839 Returns the datetime parser class
1843 sub datetime_parser {
1845 return $self->{datetime_parser} ||= do {
1846 $self->ensure_connected;
1847 $self->build_datetime_parser(@_);
1851 =head2 datetime_parser_type
1853 Defines (returns) the datetime parser class - currently hardwired to
1854 L<DateTime::Format::MySQL>
1858 sub datetime_parser_type { "DateTime::Format::MySQL"; }
1860 =head2 build_datetime_parser
1862 See L</datetime_parser>
1866 sub build_datetime_parser {
1868 my $type = $self->datetime_parser_type(@_);
1870 $self->throw_exception("Couldn't load ${type}: $@") if $@;
1875 my $_check_sqlt_version; # private
1876 my $_check_sqlt_message; # private
1877 sub _check_sqlt_version {
1878 return $_check_sqlt_version if defined $_check_sqlt_version;
1879 eval 'use SQL::Translator "0.09003"';
1880 $_check_sqlt_message = $@ || '';
1881 $_check_sqlt_version = !$@;
1884 sub _check_sqlt_message {
1885 _check_sqlt_version if !defined $_check_sqlt_message;
1886 $_check_sqlt_message;
1890 =head2 is_replicating
1892 A boolean that reports if a particular L<DBIx::Class::Storage::DBI> is set to
1893 replicate from a master database. Default is undef, which is the result
1894 returned by databases that don't support replication.
1898 sub is_replicating {
1903 =head2 lag_behind_master
1905 Returns a number that represents a certain amount of lag behind a master db
1906 when a given storage is replicating. The number is database dependent, but
1907 starts at zero and increases with the amount of lag. Default in undef
1911 sub lag_behind_master {
1917 return if !$self->_dbh;
1926 =head2 DBIx::Class and AutoCommit
1928 DBIx::Class can do some wonderful magic with handling exceptions,
1929 disconnections, and transactions when you use C<< AutoCommit => 1 >>
1930 combined with C<txn_do> for transaction support.
1932 If you set C<< AutoCommit => 0 >> in your connect info, then you are always
1933 in an assumed transaction between commits, and you're telling us you'd
1934 like to manage that manually. A lot of the magic protections offered by
1935 this module will go away. We can't protect you from exceptions due to database
1936 disconnects because we don't know anything about how to restart your
1937 transactions. You're on your own for handling all sorts of exceptional
1938 cases if you choose the C<< AutoCommit => 0 >> path, just as you would
1945 Matt S. Trout <mst@shadowcatsystems.co.uk>
1947 Andy Grundman <andy@hybridized.org>
1951 You may distribute this code under the same terms as Perl itself.