1 package DBIx::Class::Storage::DBI;
2 # -*- mode: cperl; cperl-indent-level: 2 -*-
7 use base 'DBIx::Class::Storage';
10 use Carp::Clan qw/^DBIx::Class/;
12 use DBIx::Class::Storage::DBI::Cursor;
13 use DBIx::Class::Storage::Statistics;
16 use Data::Dumper::Concise();
18 # what version of sqlt do we require if deploy() without a ddl_dir is invoked
19 # when changing also adjust the corresponding author_require in Makefile.PL
20 my $minimum_sqlt_version = '0.11002';
23 __PACKAGE__->mk_group_accessors('simple' =>
24 qw/_connect_info _dbi_connect_info _dbh _sql_maker _sql_maker_opts _conn_pid
25 _conn_tid transaction_depth _dbh_autocommit _driver_determined savepoints/
28 # the values for these accessors are picked out (and deleted) from
29 # the attribute hashref passed to connect_info
30 my @storage_options = qw/
31 on_connect_call on_disconnect_call on_connect_do on_disconnect_do
32 disable_sth_caching unsafe auto_savepoint
34 __PACKAGE__->mk_group_accessors('simple' => @storage_options);
37 # default cursor class, overridable in connect_info attributes
38 __PACKAGE__->cursor_class('DBIx::Class::Storage::DBI::Cursor');
40 __PACKAGE__->mk_group_accessors('inherited' => qw/sql_maker_class/);
41 __PACKAGE__->sql_maker_class('DBIx::Class::SQLAHacks');
44 # Each of these methods need _determine_driver called before itself
45 # in order to function reliably. This is a purely DRY optimization
46 my @rdbms_specific_methods = qw/
59 for my $meth (@rdbms_specific_methods) {
61 my $orig = __PACKAGE__->can ($meth)
65 no warnings qw/redefine/;
66 *{__PACKAGE__ ."::$meth"} = sub {
67 if (not $_[0]->_driver_determined) {
68 $_[0]->_determine_driver;
69 goto $_[0]->can($meth);
78 DBIx::Class::Storage::DBI - DBI storage handler
82 my $schema = MySchema->connect('dbi:SQLite:my.db');
84 $schema->storage->debug(1);
86 my @stuff = $schema->storage->dbh_do(
88 my ($storage, $dbh, @args) = @_;
89 $dbh->do("DROP TABLE authors");
94 $schema->resultset('Book')->search({
95 written_on => $schema->storage->datetime_parser(DateTime->now)
100 This class represents the connection to an RDBMS via L<DBI>. See
101 L<DBIx::Class::Storage> for general information. This pod only
102 documents DBI-specific methods and behaviors.
109 my $new = shift->next::method(@_);
111 $new->transaction_depth(0);
112 $new->_sql_maker_opts({});
113 $new->{savepoints} = [];
114 $new->{_in_dbh_do} = 0;
115 $new->{_dbh_gen} = 0;
122 This method is normally called by L<DBIx::Class::Schema/connection>, which
123 encapsulates its argument list in an arrayref before passing them here.
125 The argument list may contain:
131 The same 4-element argument set one would normally pass to
132 L<DBI/connect>, optionally followed by
133 L<extra attributes|/DBIx::Class specific connection attributes>
134 recognized by DBIx::Class:
136 $connect_info_args = [ $dsn, $user, $password, \%dbi_attributes?, \%extra_attributes? ];
140 A single code reference which returns a connected
141 L<DBI database handle|DBI/connect> optionally followed by
142 L<extra attributes|/DBIx::Class specific connection attributes> recognized
145 $connect_info_args = [ sub { DBI->connect (...) }, \%extra_attributes? ];
149 A single hashref with all the attributes and the dsn/user/password
152 $connect_info_args = [{
160 $connect_info_args = [{
161 dbh_maker => sub { DBI->connect (...) },
166 This is particularly useful for L<Catalyst> based applications, allowing the
167 following config (L<Config::General> style):
172 dsn dbi:mysql:database=test
179 The C<dsn>/C<user>/C<password> combination can be substituted by the
180 C<dbh_maker> key whose value is a coderef that returns a connected
181 L<DBI database handle|DBI/connect>
185 Please note that the L<DBI> docs recommend that you always explicitly
186 set C<AutoCommit> to either I<0> or I<1>. L<DBIx::Class> further
187 recommends that it be set to I<1>, and that you perform transactions
188 via our L<DBIx::Class::Schema/txn_do> method. L<DBIx::Class> will set it
189 to I<1> if you do not do explicitly set it to zero. This is the default
190 for most DBDs. See L</DBIx::Class and AutoCommit> for details.
192 =head3 DBIx::Class specific connection attributes
194 In addition to the standard L<DBI|DBI/ATTRIBUTES_COMMON_TO_ALL_HANDLES>
195 L<connection|DBI/Database_Handle_Attributes> attributes, DBIx::Class recognizes
196 the following connection options. These options can be mixed in with your other
197 L<DBI> connection attributes, or placed in a seperate hashref
198 (C<\%extra_attributes>) as shown above.
200 Every time C<connect_info> is invoked, any previous settings for
201 these options will be cleared before setting the new ones, regardless of
202 whether any options are specified in the new C<connect_info>.
209 Specifies things to do immediately after connecting or re-connecting to
210 the database. Its value may contain:
216 This contains one SQL statement to execute.
218 =item an array reference
220 This contains SQL statements to execute in order. Each element contains
221 a string or a code reference that returns a string.
223 =item a code reference
225 This contains some code to execute. Unlike code references within an
226 array reference, its return value is ignored.
230 =item on_disconnect_do
232 Takes arguments in the same form as L</on_connect_do> and executes them
233 immediately before disconnecting from the database.
235 Note, this only runs if you explicitly call L</disconnect> on the
238 =item on_connect_call
240 A more generalized form of L</on_connect_do> that calls the specified
241 C<connect_call_METHOD> methods in your storage driver.
243 on_connect_do => 'select 1'
247 on_connect_call => [ [ do_sql => 'select 1' ] ]
249 Its values may contain:
255 Will call the C<connect_call_METHOD> method.
257 =item a code reference
259 Will execute C<< $code->($storage) >>
261 =item an array reference
263 Each value can be a method name or code reference.
265 =item an array of arrays
267 For each array, the first item is taken to be the C<connect_call_> method name
268 or code reference, and the rest are parameters to it.
272 Some predefined storage methods you may use:
278 Executes a SQL string or a code reference that returns a SQL string. This is
279 what L</on_connect_do> and L</on_disconnect_do> use.
287 Will execute the scalar as SQL.
291 Taken to be arguments to L<DBI/do>, the SQL string optionally followed by the
292 attributes hashref and bind values.
294 =item a code reference
296 Will execute C<< $code->($storage) >> and execute the return array refs as
303 Execute any statements necessary to initialize the database session to return
304 and accept datetime/timestamp values used with
305 L<DBIx::Class::InflateColumn::DateTime>.
307 Only necessary for some databases, see your specific storage driver for
308 implementation details.
312 =item on_disconnect_call
314 Takes arguments in the same form as L</on_connect_call> and executes them
315 immediately before disconnecting from the database.
317 Calls the C<disconnect_call_METHOD> methods as opposed to the
318 C<connect_call_METHOD> methods called by L</on_connect_call>.
320 Note, this only runs if you explicitly call L</disconnect> on the
323 =item disable_sth_caching
325 If set to a true value, this option will disable the caching of
326 statement handles via L<DBI/prepare_cached>.
330 Sets the limit dialect. This is useful for JDBC-bridge among others
331 where the remote SQL-dialect cannot be determined by the name of the
332 driver alone. See also L<SQL::Abstract::Limit>.
336 Specifies what characters to use to quote table and column names. If
337 you use this you will want to specify L</name_sep> as well.
339 C<quote_char> expects either a single character, in which case is it
340 is placed on either side of the table/column name, or an arrayref of length
341 2 in which case the table/column name is placed between the elements.
343 For example under MySQL you should use C<< quote_char => '`' >>, and for
344 SQL Server you should use C<< quote_char => [qw/[ ]/] >>.
348 This only needs to be used in conjunction with C<quote_char>, and is used to
349 specify the charecter that seperates elements (schemas, tables, columns) from
350 each other. In most cases this is simply a C<.>.
352 The consequences of not supplying this value is that L<SQL::Abstract>
353 will assume DBIx::Class' uses of aliases to be complete column
354 names. The output will look like I<"me.name"> when it should actually
359 This Storage driver normally installs its own C<HandleError>, sets
360 C<RaiseError> and C<ShowErrorStatement> on, and sets C<PrintError> off on
361 all database handles, including those supplied by a coderef. It does this
362 so that it can have consistent and useful error behavior.
364 If you set this option to a true value, Storage will not do its usual
365 modifications to the database handle's attributes, and instead relies on
366 the settings in your connect_info DBI options (or the values you set in
367 your connection coderef, in the case that you are connecting via coderef).
369 Note that your custom settings can cause Storage to malfunction,
370 especially if you set a C<HandleError> handler that suppresses exceptions
371 and/or disable C<RaiseError>.
375 If this option is true, L<DBIx::Class> will use savepoints when nesting
376 transactions, making it possible to recover from failure in the inner
377 transaction without having to abort all outer transactions.
381 Use this argument to supply a cursor class other than the default
382 L<DBIx::Class::Storage::DBI::Cursor>.
386 Some real-life examples of arguments to L</connect_info> and
387 L<DBIx::Class::Schema/connect>
389 # Simple SQLite connection
390 ->connect_info([ 'dbi:SQLite:./foo.db' ]);
393 ->connect_info([ sub { DBI->connect(...) } ]);
395 # Connect via subref in hashref
397 dbh_maker => sub { DBI->connect(...) },
398 on_connect_do => 'alter session ...',
401 # A bit more complicated
408 { quote_char => q{"}, name_sep => q{.} },
412 # Equivalent to the previous example
418 { AutoCommit => 1, quote_char => q{"}, name_sep => q{.} },
422 # Same, but with hashref as argument
423 # See parse_connect_info for explanation
426 dsn => 'dbi:Pg:dbname=foo',
428 password => 'my_pg_password',
435 # Subref + DBIx::Class-specific connection options
438 sub { DBI->connect(...) },
442 on_connect_do => ['SET search_path TO myschema,otherschema,public'],
443 disable_sth_caching => 1,
453 my ($self, $info_arg) = @_;
455 return $self->_connect_info if !$info_arg;
457 my @args = @$info_arg; # take a shallow copy for further mutilation
458 $self->_connect_info([@args]); # copy for _connect_info
461 # combine/pre-parse arguments depending on invocation style
464 if (ref $args[0] eq 'CODE') { # coderef with optional \%extra_attributes
465 %attrs = %{ $args[1] || {} };
468 elsif (ref $args[0] eq 'HASH') { # single hashref (i.e. Catalyst config)
469 %attrs = %{$args[0]};
471 if (my $code = delete $attrs{dbh_maker}) {
474 my @ignored = grep { delete $attrs{$_} } (qw/dsn user password/);
477 'Attribute(s) %s in connect_info were ignored, as they can not be applied '
478 . "to the result of 'dbh_maker'",
480 join (', ', map { "'$_'" } (@ignored) ),
485 @args = delete @attrs{qw/dsn user password/};
488 else { # otherwise assume dsn/user/password + \%attrs + \%extra_attrs
490 % { $args[3] || {} },
491 % { $args[4] || {} },
493 @args = @args[0,1,2];
496 # Kill sql_maker/_sql_maker_opts, so we get a fresh one with only
497 # the new set of options
498 $self->_sql_maker(undef);
499 $self->_sql_maker_opts({});
502 for my $storage_opt (@storage_options, 'cursor_class') { # @storage_options is declared at the top of the module
503 if(my $value = delete $attrs{$storage_opt}) {
504 $self->$storage_opt($value);
507 for my $sql_maker_opt (qw/limit_dialect quote_char name_sep/) {
508 if(my $opt_val = delete $attrs{$sql_maker_opt}) {
509 $self->_sql_maker_opts->{$sql_maker_opt} = $opt_val;
514 if (ref $args[0] eq 'CODE') {
515 # _connect() never looks past $args[0] in this case
519 %{ $self->_default_dbi_connect_attributes || {} },
524 $self->_dbi_connect_info([@args, keys %attrs ? \%attrs : ()]);
525 $self->_connect_info;
528 sub _default_dbi_connect_attributes {
538 This method is deprecated in favour of setting via L</connect_info>.
542 =head2 on_disconnect_do
544 This method is deprecated in favour of setting via L</connect_info>.
548 sub _parse_connect_do {
549 my ($self, $type) = @_;
551 my $val = $self->$type;
552 return () if not defined $val;
557 push @res, [ 'do_sql', $val ];
558 } elsif (ref($val) eq 'CODE') {
560 } elsif (ref($val) eq 'ARRAY') {
561 push @res, map { [ 'do_sql', $_ ] } @$val;
563 $self->throw_exception("Invalid type for $type: ".ref($val));
571 Arguments: ($subref | $method_name), @extra_coderef_args?
573 Execute the given $subref or $method_name using the new exception-based
574 connection management.
576 The first two arguments will be the storage object that C<dbh_do> was called
577 on and a database handle to use. Any additional arguments will be passed
578 verbatim to the called subref as arguments 2 and onwards.
580 Using this (instead of $self->_dbh or $self->dbh) ensures correct
581 exception handling and reconnection (or failover in future subclasses).
583 Your subref should have no side-effects outside of the database, as
584 there is the potential for your subref to be partially double-executed
585 if the database connection was stale/dysfunctional.
589 my @stuff = $schema->storage->dbh_do(
591 my ($storage, $dbh, @cols) = @_;
592 my $cols = join(q{, }, @cols);
593 $dbh->selectrow_array("SELECT $cols FROM foo");
604 my $dbh = $self->_get_dbh;
606 return $self->$code($dbh, @_) if $self->{_in_dbh_do}
607 || $self->{transaction_depth};
609 local $self->{_in_dbh_do} = 1;
612 my $want_array = wantarray;
617 @result = $self->$code($dbh, @_);
619 elsif(defined $want_array) {
620 $result[0] = $self->$code($dbh, @_);
623 $self->$code($dbh, @_);
627 # ->connected might unset $@ - copy
629 if(!$exception) { return $want_array ? @result : $result[0] }
631 $self->throw_exception($exception) if $self->connected;
633 # We were not connected - reconnect and retry, but let any
634 # exception fall right through this time
635 carp "Retrying $code after catching disconnected exception: $exception"
636 if $ENV{DBIC_DBIRETRY_DEBUG};
637 $self->_populate_dbh;
638 $self->$code($self->_dbh, @_);
641 # This is basically a blend of dbh_do above and DBIx::Class::Storage::txn_do.
642 # It also informs dbh_do to bypass itself while under the direction of txn_do,
643 # via $self->{_in_dbh_do} (this saves some redundant eval and errorcheck, etc)
648 ref $coderef eq 'CODE' or $self->throw_exception
649 ('$coderef must be a CODE reference');
651 return $coderef->(@_) if $self->{transaction_depth} && ! $self->auto_savepoint;
653 local $self->{_in_dbh_do} = 1;
656 my $want_array = wantarray;
665 @result = $coderef->(@_);
667 elsif(defined $want_array) {
668 $result[0] = $coderef->(@_);
676 # ->connected might unset $@ - copy
678 if(!$exception) { return $want_array ? @result : $result[0] }
680 if($tried++ || $self->connected) {
681 eval { $self->txn_rollback };
682 my $rollback_exception = $@;
683 if($rollback_exception) {
684 my $exception_class = "DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION";
685 $self->throw_exception($exception) # propagate nested rollback
686 if $rollback_exception =~ /$exception_class/;
688 $self->throw_exception(
689 "Transaction aborted: ${exception}. "
690 . "Rollback failed: ${rollback_exception}"
693 $self->throw_exception($exception)
696 # We were not connected, and was first try - reconnect and retry
698 carp "Retrying $coderef after catching disconnected exception: $exception"
699 if $ENV{DBIC_DBIRETRY_DEBUG};
700 $self->_populate_dbh;
706 Our C<disconnect> method also performs a rollback first if the
707 database is not in C<AutoCommit> mode.
717 push @actions, ( $self->on_disconnect_call || () );
718 push @actions, $self->_parse_connect_do ('on_disconnect_do');
720 $self->_do_connection_actions(disconnect_call_ => $_) for @actions;
722 $self->_dbh_rollback unless $self->_dbh_autocommit;
724 $self->_dbh->disconnect;
730 =head2 with_deferred_fk_checks
734 =item Arguments: C<$coderef>
736 =item Return Value: The return value of $coderef
740 Storage specific method to run the code ref with FK checks deferred or
741 in MySQL's case disabled entirely.
745 # Storage subclasses should override this
746 sub with_deferred_fk_checks {
747 my ($self, $sub) = @_;
755 =item Arguments: none
757 =item Return Value: 1|0
761 Verifies that the the current database handle is active and ready to execute
762 an SQL statement (i.e. the connection did not get stale, server is still
763 answering, etc.) This method is used internally by L</dbh>.
769 return 0 unless $self->_seems_connected;
772 local $self->_dbh->{RaiseError} = 1;
777 sub _seems_connected {
780 my $dbh = $self->_dbh
783 if(defined $self->_conn_tid && $self->_conn_tid != threads->tid) {
790 return 0 if !$self->_dbh;
793 return $dbh->FETCH('Active');
799 my $dbh = $self->_dbh or return 0;
804 # handle pid changes correctly
805 # NOTE: assumes $self->_dbh is a valid $dbh
809 return if defined $self->_conn_pid && $self->_conn_pid == $$;
811 $self->_dbh->{InactiveDestroy} = 1;
818 sub ensure_connected {
821 unless ($self->connected) {
822 $self->_populate_dbh;
828 Returns a C<$dbh> - a data base handle of class L<DBI>. The returned handle
829 is guaranteed to be healthy by implicitly calling L</connected>, and if
830 necessary performing a reconnection before returning. Keep in mind that this
831 is very B<expensive> on some database engines. Consider using L<dbh_do>
839 if (not $self->_dbh) {
840 $self->_populate_dbh;
842 $self->ensure_connected;
847 # this is the internal "get dbh or connect (don't check)" method
850 $self->_verify_pid if $self->_dbh;
851 $self->_populate_dbh unless $self->_dbh;
855 sub _sql_maker_args {
860 array_datatypes => 1,
861 limit_dialect => $self->_get_dbh,
862 %{$self->_sql_maker_opts}
868 unless ($self->_sql_maker) {
869 my $sql_maker_class = $self->sql_maker_class;
870 $self->ensure_class_loaded ($sql_maker_class);
871 $self->_sql_maker($sql_maker_class->new( $self->_sql_maker_args ));
873 return $self->_sql_maker;
876 # nothing to do by default
883 my @info = @{$self->_dbi_connect_info || []};
884 $self->_dbh(undef); # in case ->connected failed we might get sent here
885 $self->_dbh($self->_connect(@info));
887 $self->_conn_pid($$);
888 $self->_conn_tid(threads->tid) if $INC{'threads.pm'};
890 $self->_determine_driver;
892 # Always set the transaction depth on connect, since
893 # there is no transaction in progress by definition
894 $self->{transaction_depth} = $self->_dbh_autocommit ? 0 : 1;
896 $self->_run_connection_actions unless $self->{_in_determine_driver};
899 sub _run_connection_actions {
903 push @actions, ( $self->on_connect_call || () );
904 push @actions, $self->_parse_connect_do ('on_connect_do');
906 $self->_do_connection_actions(connect_call_ => $_) for @actions;
909 sub _determine_driver {
912 if ((not $self->_driver_determined) && (not $self->{_in_determine_driver})) {
913 my $started_connected = 0;
914 local $self->{_in_determine_driver} = 1;
916 if (ref($self) eq __PACKAGE__) {
918 if ($self->_dbh) { # we are connected
919 $driver = $self->_dbh->{Driver}{Name};
920 $started_connected = 1;
922 # if connect_info is a CODEREF, we have no choice but to connect
923 if (ref $self->_dbi_connect_info->[0] &&
924 Scalar::Util::reftype($self->_dbi_connect_info->[0]) eq 'CODE') {
925 $self->_populate_dbh;
926 $driver = $self->_dbh->{Driver}{Name};
929 # try to use dsn to not require being connected, the driver may still
930 # force a connection in _rebless to determine version
931 ($driver) = $self->_dbi_connect_info->[0] =~ /dbi:([^:]+):/i;
935 my $storage_class = "DBIx::Class::Storage::DBI::${driver}";
936 if ($self->load_optional_class($storage_class)) {
937 mro::set_mro($storage_class, 'c3');
938 bless $self, $storage_class;
943 $self->_driver_determined(1);
945 $self->_init; # run driver-specific initializations
947 $self->_run_connection_actions
948 if !$started_connected && defined $self->_dbh;
952 sub _do_connection_actions {
954 my $method_prefix = shift;
957 if (not ref($call)) {
958 my $method = $method_prefix . $call;
960 } elsif (ref($call) eq 'CODE') {
962 } elsif (ref($call) eq 'ARRAY') {
963 if (ref($call->[0]) ne 'ARRAY') {
964 $self->_do_connection_actions($method_prefix, $_) for @$call;
966 $self->_do_connection_actions($method_prefix, @$_) for @$call;
969 $self->throw_exception (sprintf ("Don't know how to process conection actions of type '%s'", ref($call)) );
975 sub connect_call_do_sql {
977 $self->_do_query(@_);
980 sub disconnect_call_do_sql {
982 $self->_do_query(@_);
985 # override in db-specific backend when necessary
986 sub connect_call_datetime_setup { 1 }
989 my ($self, $action) = @_;
991 if (ref $action eq 'CODE') {
992 $action = $action->($self);
993 $self->_do_query($_) foreach @$action;
996 # Most debuggers expect ($sql, @bind), so we need to exclude
997 # the attribute hash which is the second argument to $dbh->do
998 # furthermore the bind values are usually to be presented
999 # as named arrayref pairs, so wrap those here too
1000 my @do_args = (ref $action eq 'ARRAY') ? (@$action) : ($action);
1001 my $sql = shift @do_args;
1002 my $attrs = shift @do_args;
1003 my @bind = map { [ undef, $_ ] } @do_args;
1005 $self->_query_start($sql, @bind);
1006 $self->_get_dbh->do($sql, $attrs, @do_args);
1007 $self->_query_end($sql, @bind);
1014 my ($self, @info) = @_;
1016 $self->throw_exception("You failed to provide any connection info")
1019 my ($old_connect_via, $dbh);
1021 if ($INC{'Apache/DBI.pm'} && $ENV{MOD_PERL}) {
1022 $old_connect_via = $DBI::connect_via;
1023 $DBI::connect_via = 'connect';
1027 if(ref $info[0] eq 'CODE') {
1031 $dbh = DBI->connect(@info);
1034 if($dbh && !$self->unsafe) {
1035 my $weak_self = $self;
1036 Scalar::Util::weaken($weak_self);
1037 $dbh->{HandleError} = sub {
1039 $weak_self->throw_exception("DBI Exception: $_[0]");
1042 # the handler may be invoked by something totally out of
1044 croak ("DBI Exception: $_[0]");
1047 $dbh->{ShowErrorStatement} = 1;
1048 $dbh->{RaiseError} = 1;
1049 $dbh->{PrintError} = 0;
1053 $DBI::connect_via = $old_connect_via if $old_connect_via;
1055 $self->throw_exception("DBI Connection failed: " . ($@||$DBI::errstr))
1058 $self->_dbh_autocommit($dbh->{AutoCommit});
1064 my ($self, $name) = @_;
1066 $name = $self->_svp_generate_name
1067 unless defined $name;
1069 $self->throw_exception ("You can't use savepoints outside a transaction")
1070 if $self->{transaction_depth} == 0;
1072 $self->throw_exception ("Your Storage implementation doesn't support savepoints")
1073 unless $self->can('_svp_begin');
1075 push @{ $self->{savepoints} }, $name;
1077 $self->debugobj->svp_begin($name) if $self->debug;
1079 return $self->_svp_begin($name);
1083 my ($self, $name) = @_;
1085 $self->throw_exception ("You can't use savepoints outside a transaction")
1086 if $self->{transaction_depth} == 0;
1088 $self->throw_exception ("Your Storage implementation doesn't support savepoints")
1089 unless $self->can('_svp_release');
1091 if (defined $name) {
1092 $self->throw_exception ("Savepoint '$name' does not exist")
1093 unless grep { $_ eq $name } @{ $self->{savepoints} };
1095 # Dig through the stack until we find the one we are releasing. This keeps
1096 # the stack up to date.
1099 do { $svp = pop @{ $self->{savepoints} } } while $svp ne $name;
1101 $name = pop @{ $self->{savepoints} };
1104 $self->debugobj->svp_release($name) if $self->debug;
1106 return $self->_svp_release($name);
1110 my ($self, $name) = @_;
1112 $self->throw_exception ("You can't use savepoints outside a transaction")
1113 if $self->{transaction_depth} == 0;
1115 $self->throw_exception ("Your Storage implementation doesn't support savepoints")
1116 unless $self->can('_svp_rollback');
1118 if (defined $name) {
1119 # If they passed us a name, verify that it exists in the stack
1120 unless(grep({ $_ eq $name } @{ $self->{savepoints} })) {
1121 $self->throw_exception("Savepoint '$name' does not exist!");
1124 # Dig through the stack until we find the one we are releasing. This keeps
1125 # the stack up to date.
1126 while(my $s = pop(@{ $self->{savepoints} })) {
1127 last if($s eq $name);
1129 # Add the savepoint back to the stack, as a rollback doesn't remove the
1130 # named savepoint, only everything after it.
1131 push(@{ $self->{savepoints} }, $name);
1133 # We'll assume they want to rollback to the last savepoint
1134 $name = $self->{savepoints}->[-1];
1137 $self->debugobj->svp_rollback($name) if $self->debug;
1139 return $self->_svp_rollback($name);
1142 sub _svp_generate_name {
1145 return 'savepoint_'.scalar(@{ $self->{'savepoints'} });
1150 if($self->{transaction_depth} == 0) {
1151 $self->debugobj->txn_begin()
1153 $self->_dbh_begin_work;
1155 elsif ($self->auto_savepoint) {
1158 $self->{transaction_depth}++;
1161 sub _dbh_begin_work {
1164 # if the user is utilizing txn_do - good for him, otherwise we need to
1165 # ensure that the $dbh is healthy on BEGIN.
1166 # We do this via ->dbh_do instead of ->dbh, so that the ->dbh "ping"
1167 # will be replaced by a failure of begin_work itself (which will be
1168 # then retried on reconnect)
1169 if ($self->{_in_dbh_do}) {
1170 $self->_dbh->begin_work;
1172 $self->dbh_do(sub { $_[1]->begin_work });
1178 if ($self->{transaction_depth} == 1) {
1179 $self->debugobj->txn_commit()
1182 $self->{transaction_depth} = 0
1183 if $self->_dbh_autocommit;
1185 elsif($self->{transaction_depth} > 1) {
1186 $self->{transaction_depth}--;
1188 if $self->auto_savepoint;
1194 my $dbh = $self->_dbh
1195 or $self->throw_exception('cannot COMMIT on a disconnected handle');
1201 my $dbh = $self->_dbh;
1203 if ($self->{transaction_depth} == 1) {
1204 $self->debugobj->txn_rollback()
1206 $self->{transaction_depth} = 0
1207 if $self->_dbh_autocommit;
1208 $self->_dbh_rollback;
1210 elsif($self->{transaction_depth} > 1) {
1211 $self->{transaction_depth}--;
1212 if ($self->auto_savepoint) {
1213 $self->svp_rollback;
1218 die DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION->new;
1223 my $exception_class = "DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION";
1224 $error =~ /$exception_class/ and $self->throw_exception($error);
1225 # ensure that a failed rollback resets the transaction depth
1226 $self->{transaction_depth} = $self->_dbh_autocommit ? 0 : 1;
1227 $self->throw_exception($error);
1233 my $dbh = $self->_dbh
1234 or $self->throw_exception('cannot ROLLBACK on a disconnected handle');
1238 # This used to be the top-half of _execute. It was split out to make it
1239 # easier to override in NoBindVars without duping the rest. It takes up
1240 # all of _execute's args, and emits $sql, @bind.
1241 sub _prep_for_execute {
1242 my ($self, $op, $extra_bind, $ident, $args) = @_;
1244 if( Scalar::Util::blessed($ident) && $ident->isa("DBIx::Class::ResultSource") ) {
1245 $ident = $ident->from();
1248 my ($sql, @bind) = $self->sql_maker->$op($ident, @$args);
1251 map { ref $_ eq 'ARRAY' ? $_ : [ '!!dummy', $_ ] } @$extra_bind)
1253 return ($sql, \@bind);
1257 sub _fix_bind_params {
1258 my ($self, @bind) = @_;
1260 ### Turn @bind from something like this:
1261 ### ( [ "artist", 1 ], [ "cdid", 1, 3 ] )
1263 ### ( "'1'", "'1'", "'3'" )
1266 if ( defined( $_ && $_->[1] ) ) {
1267 map { qq{'$_'}; } @{$_}[ 1 .. $#$_ ];
1274 my ( $self, $sql, @bind ) = @_;
1276 if ( $self->debug ) {
1277 @bind = $self->_fix_bind_params(@bind);
1279 $self->debugobj->query_start( $sql, @bind );
1284 my ( $self, $sql, @bind ) = @_;
1286 if ( $self->debug ) {
1287 @bind = $self->_fix_bind_params(@bind);
1288 $self->debugobj->query_end( $sql, @bind );
1293 my ($self, $dbh, $op, $extra_bind, $ident, $bind_attributes, @args) = @_;
1295 my ($sql, $bind) = $self->_prep_for_execute($op, $extra_bind, $ident, \@args);
1297 $self->_query_start( $sql, @$bind );
1299 my $sth = $self->sth($sql,$op);
1301 my $placeholder_index = 1;
1303 foreach my $bound (@$bind) {
1304 my $attributes = {};
1305 my($column_name, @data) = @$bound;
1307 if ($bind_attributes) {
1308 $attributes = $bind_attributes->{$column_name}
1309 if defined $bind_attributes->{$column_name};
1312 foreach my $data (@data) {
1313 my $ref = ref $data;
1314 $data = $ref && $ref ne 'ARRAY' ? ''.$data : $data; # stringify args (except arrayrefs)
1316 $sth->bind_param($placeholder_index, $data, $attributes);
1317 $placeholder_index++;
1321 # Can this fail without throwing an exception anyways???
1322 my $rv = $sth->execute();
1323 $self->throw_exception($sth->errstr) if !$rv;
1325 $self->_query_end( $sql, @$bind );
1327 return (wantarray ? ($rv, $sth, @$bind) : $rv);
1332 $self->dbh_do('_dbh_execute', @_); # retry over disconnects
1336 my ($self, $source, $to_insert) = @_;
1338 my $ident = $source->from;
1339 my $bind_attributes = $self->source_bind_attributes($source);
1341 my $updated_cols = {};
1343 foreach my $col ( $source->columns ) {
1344 if ( !defined $to_insert->{$col} ) {
1345 my $col_info = $source->column_info($col);
1347 if ( $col_info->{auto_nextval} ) {
1348 $updated_cols->{$col} = $to_insert->{$col} = $self->_sequence_fetch(
1350 $col_info->{sequence} ||
1351 $self->_dbh_get_autoinc_seq($self->_get_dbh, $source)
1357 $self->_execute('insert' => [], $source, $bind_attributes, $to_insert);
1359 return $updated_cols;
1362 ## Still not quite perfect, and EXPERIMENTAL
1363 ## Currently it is assumed that all values passed will be "normal", i.e. not
1364 ## scalar refs, or at least, all the same type as the first set, the statement is
1365 ## only prepped once.
1367 my ($self, $source, $cols, $data) = @_;
1370 @colvalues{@$cols} = (0..$#$cols);
1372 for my $i (0..$#$cols) {
1373 my $first_val = $data->[0][$i];
1374 next unless ref $first_val eq 'SCALAR';
1376 $colvalues{ $cols->[$i] } = $first_val;
1379 # check for bad data and stringify stringifiable objects
1380 my $bad_slice = sub {
1381 my ($msg, $col_idx, $slice_idx) = @_;
1382 $self->throw_exception(sprintf "%s for column '%s' in populate slice:\n%s",
1386 local $Data::Dumper::Maxdepth = 1; # don't dump objects, if any
1387 Data::Dumper::Concise::Dumper({
1388 map { $cols->[$_] => $data->[$slice_idx][$_] } (0 .. $#$cols)
1394 for my $datum_idx (0..$#$data) {
1395 my $datum = $data->[$datum_idx];
1397 for my $col_idx (0..$#$cols) {
1398 my $val = $datum->[$col_idx];
1399 my $sqla_bind = $colvalues{ $cols->[$col_idx] };
1400 my $is_literal_sql = (ref $sqla_bind) eq 'SCALAR';
1402 if ($is_literal_sql) {
1404 $bad_slice->('bind found where literal SQL expected', $col_idx, $datum_idx);
1406 elsif ((my $reftype = ref $val) ne 'SCALAR') {
1407 $bad_slice->("$reftype reference found where literal SQL expected",
1408 $col_idx, $datum_idx);
1410 elsif ($$val ne $$sqla_bind){
1411 $bad_slice->("inconsistent literal SQL value, expecting: '$$sqla_bind'",
1412 $col_idx, $datum_idx);
1415 elsif (my $reftype = ref $val) {
1417 if (overload::Method($val, '""')) {
1418 $datum->[$col_idx] = "".$val;
1421 $bad_slice->("$reftype reference found where bind expected",
1422 $col_idx, $datum_idx);
1428 my ($sql, $bind) = $self->_prep_for_execute (
1429 'insert', undef, $source, [\%colvalues]
1433 my $empty_bind = 1 if (not @bind) &&
1434 (grep { ref $_ eq 'SCALAR' } values %colvalues) == @$cols;
1436 if ((not @bind) && (not $empty_bind)) {
1437 $self->throw_exception(
1438 'Cannot insert_bulk without support for placeholders'
1442 $self->_query_start( $sql, ['__BULK__'] );
1443 my $sth = $self->sth($sql);
1447 # bind_param_array doesn't work if there are no binds
1448 $self->_dbh_execute_inserts_with_no_binds( $sth, scalar @$data );
1451 # @bind = map { ref $_ ? ''.$_ : $_ } @bind; # stringify args
1452 $self->_execute_array( $source, $sth, \@bind, $cols, $data );
1456 $self->_query_end( $sql, ['__BULK__'] );
1458 return (wantarray ? ($rv, $sth, @bind) : $rv);
1461 sub _execute_array {
1462 my ($self, $source, $sth, $bind, $cols, $data, @extra) = @_;
1464 my $guard = $self->txn_scope_guard unless $self->{transaction_depth} != 0;
1466 ## This must be an arrayref, else nothing works!
1467 my $tuple_status = [];
1469 ## Get the bind_attributes, if any exist
1470 my $bind_attributes = $self->source_bind_attributes($source);
1472 ## Bind the values and execute
1473 my $placeholder_index = 1;
1475 foreach my $bound (@$bind) {
1477 my $attributes = {};
1478 my ($column_name, $data_index) = @$bound;
1480 if( $bind_attributes ) {
1481 $attributes = $bind_attributes->{$column_name}
1482 if defined $bind_attributes->{$column_name};
1485 my @data = map { $_->[$data_index] } @$data;
1487 $sth->bind_param_array( $placeholder_index, [@data], $attributes );
1488 $placeholder_index++;
1492 $self->_dbh_execute_array($sth, $tuple_status, @extra);
1494 my $err = $@ || $sth->errstr;
1496 # Statement must finish even if there was an exception.
1497 eval { $sth->finish };
1498 $err = $@ unless $err;
1502 ++$i while $i <= $#$tuple_status && !ref $tuple_status->[$i];
1504 $self->throw_exception("Unexpected populate error: $err")
1505 if ($i > $#$tuple_status);
1507 $self->throw_exception(sprintf "%s for populate slice:\n%s",
1508 ($tuple_status->[$i][1] || $err),
1509 Data::Dumper::Concise::Dumper({
1510 map { $cols->[$_] => $data->[$i][$_] } (0 .. $#$cols)
1515 $guard->commit if $guard;
1520 sub _dbh_execute_array {
1521 my ($self, $sth, $tuple_status, @extra) = @_;
1523 return $sth->execute_array({ArrayTupleStatus => $tuple_status});
1526 sub _dbh_execute_inserts_with_no_binds {
1527 my ($self, $sth, $count) = @_;
1529 my $guard = $self->txn_scope_guard unless $self->{transaction_depth} != 0;
1532 my $dbh = $self->_get_dbh;
1533 local $dbh->{RaiseError} = 1;
1534 local $dbh->{PrintError} = 0;
1536 $sth->execute foreach 1..$count;
1540 # Make sure statement is finished even if there was an exception.
1541 eval { $sth->finish };
1542 $exception = $@ unless $exception;
1544 $self->throw_exception($exception) if $exception;
1546 $guard->commit if $guard;
1552 my ($self, $source, $data, $where, @args) = @_;
1554 my $bind_attrs = $self->source_bind_attributes($source);
1555 $where = $self->_strip_cond_qualifiers ($where);
1557 return $self->_execute('update' => [], $source, $bind_attrs, $data, $where, @args);
1562 my ($self, $source, $where, @args) = @_;
1564 my $bind_attrs = $self->source_bind_attributes($source);
1565 $where = $self->_strip_cond_qualifiers ($where);
1567 return $self->_execute('delete' => [], $source, $bind_attrs, $where, @args);
1570 # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
1571 # a condition containing 'me' or other table prefixes will not work
1572 # at all. Since we employ subqueries when multiple tables are involved
1573 # (joins), it is relatively safe to strip all column qualifiers. Worst
1574 # case scenario the error message will be a bit misleading, if the
1575 # user supplies a foreign qualifier without a join (the message would
1576 # be "can't find column X", when in fact the user shoud join T containing
1578 sub _strip_cond_qualifiers {
1579 my ($self, $where) = @_;
1581 my $sqlmaker = $self->sql_maker;
1582 my ($sql, @bind) = $sqlmaker->_recurse_where($where);
1583 return undef unless $sql;
1585 my ($qquot, $qsep) = map { quotemeta $_ } ( ($sqlmaker->quote_char||''), ($sqlmaker->name_sep||'.') );
1586 $sql =~ s/ (?: $qquot [\w\-]+ $qquot | [\w\-]+ ) $qsep //gx;
1588 return \[$sql, @bind];
1591 # We were sent here because the $rs contains a complex search
1592 # which will require a subquery to select the correct rows
1593 # (i.e. joined or limited resultsets)
1595 # Genarating a single PK column subquery is trivial and supported
1596 # by all RDBMS. However if we have a multicolumn PK, things get ugly.
1597 # Look at _multipk_update_delete()
1598 sub _subq_update_delete {
1600 my ($rs, $op, $values) = @_;
1602 my $rsrc = $rs->result_source;
1604 # we already check this, but double check naively just in case. Should be removed soon
1605 my $sel = $rs->_resolved_attrs->{select};
1606 $sel = [ $sel ] unless ref $sel eq 'ARRAY';
1607 my @pcols = $rsrc->primary_columns;
1608 if (@$sel != @pcols) {
1609 $self->throw_exception (
1610 'Subquery update/delete can not be called on resultsets selecting a'
1611 .' number of columns different than the number of primary keys'
1618 $op eq 'update' ? $values : (),
1619 { $pcols[0] => { -in => $rs->as_query } },
1624 return $self->_multipk_update_delete (@_);
1628 # ANSI SQL does not provide a reliable way to perform a multicol-PK
1629 # resultset update/delete involving subqueries. So by default resort
1630 # to simple (and inefficient) delete_all style per-row opearations,
1631 # while allowing specific storages to override this with a faster
1634 sub _multipk_update_delete {
1635 return shift->_per_row_update_delete (@_);
1638 # This is the default loop used to delete/update rows for multi PK
1639 # resultsets, and used by mysql exclusively (because it can't do anything
1642 # We do not use $row->$op style queries, because resultset update/delete
1643 # is not expected to cascade (this is what delete_all/update_all is for).
1645 # There should be no race conditions as the entire operation is rolled
1648 sub _per_row_update_delete {
1650 my ($rs, $op, $values) = @_;
1652 my $rsrc = $rs->result_source;
1653 my @pcols = $rsrc->primary_columns;
1655 my $guard = $self->txn_scope_guard;
1657 # emulate the return value of $sth->execute for non-selects
1658 my $row_cnt = '0E0';
1660 my $subrs_cur = $rs->cursor;
1661 while (my @pks = $subrs_cur->next) {
1664 for my $i (0.. $#pcols) {
1665 $cond->{$pcols[$i]} = $pks[$i];
1670 $op eq 'update' ? $values : (),
1685 # localization is neccessary as
1686 # 1) there is no infrastructure to pass this around before SQLA2
1687 # 2) _select_args sets it and _prep_for_execute consumes it
1688 my $sql_maker = $self->sql_maker;
1689 local $sql_maker->{_dbic_rs_attrs};
1691 return $self->_execute($self->_select_args(@_));
1694 sub _select_args_to_query {
1697 # localization is neccessary as
1698 # 1) there is no infrastructure to pass this around before SQLA2
1699 # 2) _select_args sets it and _prep_for_execute consumes it
1700 my $sql_maker = $self->sql_maker;
1701 local $sql_maker->{_dbic_rs_attrs};
1703 # my ($op, $bind, $ident, $bind_attrs, $select, $cond, $order, $rows, $offset)
1704 # = $self->_select_args($ident, $select, $cond, $attrs);
1705 my ($op, $bind, $ident, $bind_attrs, @args) =
1706 $self->_select_args(@_);
1708 # my ($sql, $prepared_bind) = $self->_prep_for_execute($op, $bind, $ident, [ $select, $cond, $order, $rows, $offset ]);
1709 my ($sql, $prepared_bind) = $self->_prep_for_execute($op, $bind, $ident, \@args);
1710 $prepared_bind ||= [];
1713 ? ($sql, $prepared_bind, $bind_attrs)
1714 : \[ "($sql)", @$prepared_bind ]
1719 my ($self, $ident, $select, $where, $attrs) = @_;
1721 my ($alias2source, $rs_alias) = $self->_resolve_ident_sources ($ident);
1723 my $sql_maker = $self->sql_maker;
1724 $sql_maker->{_dbic_rs_attrs} = {
1730 ? ( _source_handle => $alias2source->{$rs_alias}->handle )
1735 # calculate bind_attrs before possible $ident mangling
1736 my $bind_attrs = {};
1737 for my $alias (keys %$alias2source) {
1738 my $bindtypes = $self->source_bind_attributes ($alias2source->{$alias}) || {};
1739 for my $col (keys %$bindtypes) {
1741 my $fqcn = join ('.', $alias, $col);
1742 $bind_attrs->{$fqcn} = $bindtypes->{$col} if $bindtypes->{$col};
1744 # Unqialified column names are nice, but at the same time can be
1745 # rather ambiguous. What we do here is basically go along with
1746 # the loop, adding an unqualified column slot to $bind_attrs,
1747 # alongside the fully qualified name. As soon as we encounter
1748 # another column by that name (which would imply another table)
1749 # we unset the unqualified slot and never add any info to it
1750 # to avoid erroneous type binding. If this happens the users
1751 # only choice will be to fully qualify his column name
1753 if (exists $bind_attrs->{$col}) {
1754 $bind_attrs->{$col} = {};
1757 $bind_attrs->{$col} = $bind_attrs->{$fqcn};
1764 $attrs->{software_limit}
1766 $sql_maker->_default_limit_syntax eq "GenericSubQ"
1768 $attrs->{software_limit} = 1;
1771 $self->throw_exception("rows attribute must be positive if present")
1772 if (defined($attrs->{rows}) && !($attrs->{rows} > 0));
1774 # MySQL actually recommends this approach. I cringe.
1775 $attrs->{rows} = 2**48 if not defined $attrs->{rows} and defined $attrs->{offset};
1780 # see if we need to tear the prefetch apart (either limited has_many or grouped prefetch)
1781 # otherwise delegate the limiting to the storage, unless software limit was requested
1783 ( $attrs->{rows} && keys %{$attrs->{collapse}} )
1785 ( $attrs->{group_by} && @{$attrs->{group_by}} &&
1786 $attrs->{_prefetch_select} && @{$attrs->{_prefetch_select}} )
1788 ($ident, $select, $where, $attrs)
1789 = $self->_adjust_select_args_for_complex_prefetch ($ident, $select, $where, $attrs);
1791 elsif (! $attrs->{software_limit} ) {
1792 push @limit, $attrs->{rows}, $attrs->{offset};
1796 # This would be the point to deflate anything found in $where
1797 # (and leave $attrs->{bind} intact). Problem is - inflators historically
1798 # expect a row object. And all we have is a resultsource (it is trivial
1799 # to extract deflator coderefs via $alias2source above).
1801 # I don't see a way forward other than changing the way deflators are
1802 # invoked, and that's just bad...
1806 { $attrs->{$_} ? ( $_ => $attrs->{$_} ) : () }
1807 (qw/order_by group_by having/ )
1810 return ('select', $attrs->{bind}, $ident, $bind_attrs, $select, $where, $order, @limit);
1814 # This is the code producing joined subqueries like:
1815 # SELECT me.*, other.* FROM ( SELECT me.* FROM ... ) JOIN other ON ...
1817 sub _adjust_select_args_for_complex_prefetch {
1818 my ($self, $from, $select, $where, $attrs) = @_;
1820 $self->throw_exception ('Nothing to prefetch... how did we get here?!')
1821 if not @{$attrs->{_prefetch_select}};
1823 $self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute')
1824 if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY');
1827 # generate inner/outer attribute lists, remove stuff that doesn't apply
1828 my $outer_attrs = { %$attrs };
1829 delete $outer_attrs->{$_} for qw/where bind rows offset group_by having/;
1831 my $inner_attrs = { %$attrs };
1832 delete $inner_attrs->{$_} for qw/for collapse _prefetch_select _collapse_order_by select as/;
1835 # bring over all non-collapse-induced order_by into the inner query (if any)
1836 # the outer one will have to keep them all
1837 delete $inner_attrs->{order_by};
1838 if (my $ord_cnt = @{$outer_attrs->{order_by}} - @{$outer_attrs->{_collapse_order_by}} ) {
1839 $inner_attrs->{order_by} = [
1840 @{$outer_attrs->{order_by}}[ 0 .. $ord_cnt - 1]
1845 # generate the inner/outer select lists
1846 # for inside we consider only stuff *not* brought in by the prefetch
1847 # on the outside we substitute any function for its alias
1848 my $outer_select = [ @$select ];
1849 my $inner_select = [];
1850 for my $i (0 .. ( @$outer_select - @{$outer_attrs->{_prefetch_select}} - 1) ) {
1851 my $sel = $outer_select->[$i];
1853 if (ref $sel eq 'HASH' ) {
1854 $sel->{-as} ||= $attrs->{as}[$i];
1855 $outer_select->[$i] = join ('.', $attrs->{alias}, ($sel->{-as} || "inner_column_$i") );
1858 push @$inner_select, $sel;
1861 # normalize a copy of $from, so it will be easier to work with further
1862 # down (i.e. promote the initial hashref to an AoH)
1864 $from->[0] = [ $from->[0] ];
1865 my %original_join_info = map { $_->[0]{-alias} => $_->[0] } (@$from);
1868 # decide which parts of the join will remain in either part of
1869 # the outer/inner query
1871 # First we compose a list of which aliases are used in restrictions
1872 # (i.e. conditions/order/grouping/etc). Since we do not have
1873 # introspectable SQLA, we fall back to ugly scanning of raw SQL for
1874 # WHERE, and for pieces of ORDER BY in order to determine which aliases
1875 # need to appear in the resulting sql.
1876 # It may not be very efficient, but it's a reasonable stop-gap
1877 # Also unqualified column names will not be considered, but more often
1878 # than not this is actually ok
1880 # In the same loop we enumerate part of the selection aliases, as
1881 # it requires the same sqla hack for the time being
1882 my ($restrict_aliases, $select_aliases, $prefetch_aliases);
1884 # produce stuff unquoted, so it can be scanned
1885 my $sql_maker = $self->sql_maker;
1886 local $sql_maker->{quote_char};
1887 my $sep = $self->_sql_maker_opts->{name_sep} || '.';
1890 my $non_prefetch_select_sql = $sql_maker->_recurse_fields ($inner_select);
1891 my $prefetch_select_sql = $sql_maker->_recurse_fields ($outer_attrs->{_prefetch_select});
1892 my $where_sql = $sql_maker->where ($where);
1893 my $group_by_sql = $sql_maker->_order_by({
1894 map { $_ => $inner_attrs->{$_} } qw/group_by having/
1896 my @non_prefetch_order_by_chunks = (map
1897 { ref $_ ? $_->[0] : $_ }
1898 $sql_maker->_order_by_chunks ($inner_attrs->{order_by})
1902 for my $alias (keys %original_join_info) {
1903 my $seen_re = qr/\b $alias $sep/x;
1905 for my $piece ($where_sql, $group_by_sql, @non_prefetch_order_by_chunks ) {
1906 if ($piece =~ $seen_re) {
1907 $restrict_aliases->{$alias} = 1;
1911 if ($non_prefetch_select_sql =~ $seen_re) {
1912 $select_aliases->{$alias} = 1;
1915 if ($prefetch_select_sql =~ $seen_re) {
1916 $prefetch_aliases->{$alias} = 1;
1922 # Add any non-left joins to the restriction list (such joins are indeed restrictions)
1923 for my $j (values %original_join_info) {
1924 my $alias = $j->{-alias} or next;
1925 $restrict_aliases->{$alias} = 1 if (
1926 (not $j->{-join_type})
1928 ($j->{-join_type} !~ /^left (?: \s+ outer)? $/xi)
1932 # mark all join parents as mentioned
1933 # (e.g. join => { cds => 'tracks' } - tracks will need to bring cds too )
1934 for my $collection ($restrict_aliases, $select_aliases) {
1935 for my $alias (keys %$collection) {
1936 $collection->{$_} = 1
1937 for (@{ $original_join_info{$alias}{-join_path} || [] });
1941 # construct the inner $from for the subquery
1942 my %inner_joins = (map { %{$_ || {}} } ($restrict_aliases, $select_aliases) );
1944 for my $j (@$from) {
1945 push @inner_from, $j if $inner_joins{$j->[0]{-alias}};
1948 # if a multi-type join was needed in the subquery ("multi" is indicated by
1949 # presence in {collapse}) - add a group_by to simulate the collapse in the subq
1950 unless ($inner_attrs->{group_by}) {
1951 for my $alias (keys %inner_joins) {
1953 # the dot comes from some weirdness in collapse
1954 # remove after the rewrite
1955 if ($attrs->{collapse}{".$alias"}) {
1956 $inner_attrs->{group_by} ||= $inner_select;
1962 # demote the inner_from head
1963 $inner_from[0] = $inner_from[0][0];
1965 # generate the subquery
1966 my $subq = $self->_select_args_to_query (
1973 my $subq_joinspec = {
1974 -alias => $attrs->{alias},
1975 -source_handle => $inner_from[0]{-source_handle},
1976 $attrs->{alias} => $subq,
1979 # Generate the outer from - this is relatively easy (really just replace
1980 # the join slot with the subquery), with a major caveat - we can not
1981 # join anything that is non-selecting (not part of the prefetch), but at
1982 # the same time is a multi-type relationship, as it will explode the result.
1984 # There are two possibilities here
1985 # - either the join is non-restricting, in which case we simply throw it away
1986 # - it is part of the restrictions, in which case we need to collapse the outer
1987 # result by tackling yet another group_by to the outside of the query
1989 # so first generate the outer_from, up to the substitution point
1991 while (my $j = shift @$from) {
1992 if ($j->[0]{-alias} eq $attrs->{alias}) { # time to swap
1997 last; # we'll take care of what's left in $from below
2000 push @outer_from, $j;
2004 # see what's left - throw away if not selecting/restricting
2005 # also throw in a group_by if restricting to guard against
2006 # cross-join explosions
2008 while (my $j = shift @$from) {
2009 my $alias = $j->[0]{-alias};
2011 if ($select_aliases->{$alias} || $prefetch_aliases->{$alias}) {
2012 push @outer_from, $j;
2014 elsif ($restrict_aliases->{$alias}) {
2015 push @outer_from, $j;
2017 # FIXME - this should be obviated by SQLA2, as I'll be able to
2018 # have restrict_inner and restrict_outer... or something to that
2019 # effect... I think...
2021 # FIXME2 - I can't find a clean way to determine if a particular join
2022 # is a multi - instead I am just treating everything as a potential
2023 # explosive join (ribasushi)
2025 # if (my $handle = $j->[0]{-source_handle}) {
2026 # my $rsrc = $handle->resolve;
2027 # ... need to bail out of the following if this is not a multi,
2028 # as it will be much easier on the db ...
2030 $outer_attrs->{group_by} ||= $outer_select;
2035 # demote the outer_from head
2036 $outer_from[0] = $outer_from[0][0];
2038 # This is totally horrific - the $where ends up in both the inner and outer query
2039 # Unfortunately not much can be done until SQLA2 introspection arrives, and even
2040 # then if where conditions apply to the *right* side of the prefetch, you may have
2041 # to both filter the inner select (e.g. to apply a limit) and then have to re-filter
2042 # the outer select to exclude joins you didin't want in the first place
2044 # OTOH it can be seen as a plus: <ash> (notes that this query would make a DBA cry ;)
2045 return (\@outer_from, $outer_select, $where, $outer_attrs);
2048 sub _resolve_ident_sources {
2049 my ($self, $ident) = @_;
2051 my $alias2source = {};
2054 # the reason this is so contrived is that $ident may be a {from}
2055 # structure, specifying multiple tables to join
2056 if ( Scalar::Util::blessed($ident) && $ident->isa("DBIx::Class::ResultSource") ) {
2057 # this is compat mode for insert/update/delete which do not deal with aliases
2058 $alias2source->{me} = $ident;
2061 elsif (ref $ident eq 'ARRAY') {
2065 if (ref $_ eq 'HASH') {
2067 $rs_alias = $tabinfo->{-alias};
2069 if (ref $_ eq 'ARRAY' and ref $_->[0] eq 'HASH') {
2073 $alias2source->{$tabinfo->{-alias}} = $tabinfo->{-source_handle}->resolve
2074 if ($tabinfo->{-source_handle});
2078 return ($alias2source, $rs_alias);
2081 # Takes $ident, \@column_names
2083 # returns { $column_name => \%column_info, ... }
2084 # also note: this adds -result_source => $rsrc to the column info
2087 # my $col_sources = $self->_resolve_column_info($ident, @column_names);
2088 sub _resolve_column_info {
2089 my ($self, $ident, $colnames) = @_;
2090 my ($alias2src, $root_alias) = $self->_resolve_ident_sources($ident);
2092 my $sep = $self->_sql_maker_opts->{name_sep} || '.';
2095 my (%return, %seen_cols);
2097 # compile a global list of column names, to be able to properly
2098 # disambiguate unqualified column names (if at all possible)
2099 for my $alias (keys %$alias2src) {
2100 my $rsrc = $alias2src->{$alias};
2101 for my $colname ($rsrc->columns) {
2102 push @{$seen_cols{$colname}}, $alias;
2107 foreach my $col (@$colnames) {
2108 my ($alias, $colname) = $col =~ m/^ (?: ([^$sep]+) $sep)? (.+) $/x;
2111 # see if the column was seen exactly once (so we know which rsrc it came from)
2112 if ($seen_cols{$colname} and @{$seen_cols{$colname}} == 1) {
2113 $alias = $seen_cols{$colname}[0];
2120 my $rsrc = $alias2src->{$alias};
2121 $return{$col} = $rsrc && {
2122 %{$rsrc->column_info($colname)},
2123 -result_source => $rsrc,
2124 -source_alias => $alias,
2131 # Returns a counting SELECT for a simple count
2132 # query. Abstracted so that a storage could override
2133 # this to { count => 'firstcol' } or whatever makes
2134 # sense as a performance optimization
2136 #my ($self, $source, $rs_attrs) = @_;
2137 return { count => '*' };
2140 # Returns a SELECT which will end up in the subselect
2141 # There may or may not be a group_by, as the subquery
2142 # might have been called to accomodate a limit
2144 # Most databases would be happy with whatever ends up
2145 # here, but some choke in various ways.
2147 sub _subq_count_select {
2148 my ($self, $source, $rs_attrs) = @_;
2149 return $rs_attrs->{group_by} if $rs_attrs->{group_by};
2151 my @pcols = map { join '.', $rs_attrs->{alias}, $_ } ($source->primary_columns);
2152 return @pcols ? \@pcols : [ 1 ];
2155 sub source_bind_attributes {
2156 my ($self, $source) = @_;
2158 my $bind_attributes;
2159 foreach my $column ($source->columns) {
2161 my $data_type = $source->column_info($column)->{data_type} || '';
2162 $bind_attributes->{$column} = $self->bind_attribute_by_data_type($data_type)
2166 return $bind_attributes;
2173 =item Arguments: $ident, $select, $condition, $attrs
2177 Handle a SQL select statement.
2183 my ($ident, $select, $condition, $attrs) = @_;
2184 return $self->cursor_class->new($self, \@_, $attrs);
2189 my ($rv, $sth, @bind) = $self->_select(@_);
2190 my @row = $sth->fetchrow_array;
2191 my @nextrow = $sth->fetchrow_array if @row;
2192 if(@row && @nextrow) {
2193 carp "Query returned more than one row. SQL that returns multiple rows is DEPRECATED for ->find and ->single";
2195 # Need to call finish() to work round broken DBDs
2204 =item Arguments: $sql
2208 Returns a L<DBI> sth (statement handle) for the supplied SQL.
2213 my ($self, $dbh, $sql) = @_;
2215 # 3 is the if_active parameter which avoids active sth re-use
2216 my $sth = $self->disable_sth_caching
2217 ? $dbh->prepare($sql)
2218 : $dbh->prepare_cached($sql, {}, 3);
2220 # XXX You would think RaiseError would make this impossible,
2221 # but apparently that's not true :(
2222 $self->throw_exception($dbh->errstr) if !$sth;
2228 my ($self, $sql) = @_;
2229 $self->dbh_do('_dbh_sth', $sql); # retry over disconnects
2232 sub _dbh_columns_info_for {
2233 my ($self, $dbh, $table) = @_;
2235 if ($dbh->can('column_info')) {
2238 my ($schema,$tab) = $table =~ /^(.+?)\.(.+)$/ ? ($1,$2) : (undef,$table);
2239 my $sth = $dbh->column_info( undef,$schema, $tab, '%' );
2241 while ( my $info = $sth->fetchrow_hashref() ){
2243 $column_info{data_type} = $info->{TYPE_NAME};
2244 $column_info{size} = $info->{COLUMN_SIZE};
2245 $column_info{is_nullable} = $info->{NULLABLE} ? 1 : 0;
2246 $column_info{default_value} = $info->{COLUMN_DEF};
2247 my $col_name = $info->{COLUMN_NAME};
2248 $col_name =~ s/^\"(.*)\"$/$1/;
2250 $result{$col_name} = \%column_info;
2253 return \%result if !$@ && scalar keys %result;
2257 my $sth = $dbh->prepare($self->sql_maker->select($table, undef, \'1 = 0'));
2259 my @columns = @{$sth->{NAME_lc}};
2260 for my $i ( 0 .. $#columns ){
2262 $column_info{data_type} = $sth->{TYPE}->[$i];
2263 $column_info{size} = $sth->{PRECISION}->[$i];
2264 $column_info{is_nullable} = $sth->{NULLABLE}->[$i] ? 1 : 0;
2266 if ($column_info{data_type} =~ m/^(.*?)\((.*?)\)$/) {
2267 $column_info{data_type} = $1;
2268 $column_info{size} = $2;
2271 $result{$columns[$i]} = \%column_info;
2275 foreach my $col (keys %result) {
2276 my $colinfo = $result{$col};
2277 my $type_num = $colinfo->{data_type};
2279 if(defined $type_num && $dbh->can('type_info')) {
2280 my $type_info = $dbh->type_info($type_num);
2281 $type_name = $type_info->{TYPE_NAME} if $type_info;
2282 $colinfo->{data_type} = $type_name if $type_name;
2289 sub columns_info_for {
2290 my ($self, $table) = @_;
2291 $self->_dbh_columns_info_for ($self->_get_dbh, $table);
2294 =head2 last_insert_id
2296 Return the row id of the last insert.
2300 sub _dbh_last_insert_id {
2301 # All Storage's need to register their own _dbh_last_insert_id
2302 # the old SQLite-based method was highly inappropriate
2305 my $class = ref $self;
2306 $self->throw_exception (<<EOE);
2308 No _dbh_last_insert_id() method found in $class.
2309 Since the method of obtaining the autoincrement id of the last insert
2310 operation varies greatly between different databases, this method must be
2311 individually implemented for every storage class.
2315 sub last_insert_id {
2317 $self->_dbh_last_insert_id ($self->_dbh, @_);
2320 =head2 _native_data_type
2324 =item Arguments: $type_name
2328 This API is B<EXPERIMENTAL>, will almost definitely change in the future, and
2329 currently only used by L<::AutoCast|DBIx::Class::Storage::DBI::AutoCast> and
2330 L<::Sybase|DBIx::Class::Storage::DBI::Sybase>.
2332 The default implementation returns C<undef>, implement in your Storage driver if
2333 you need this functionality.
2335 Should map types from other databases to the native RDBMS type, for example
2336 C<VARCHAR2> to C<VARCHAR>.
2338 Types with modifiers should map to the underlying data type. For example,
2339 C<INTEGER AUTO_INCREMENT> should become C<INTEGER>.
2341 Composite types should map to the container type, for example
2342 C<ENUM(foo,bar,baz)> becomes C<ENUM>.
2346 sub _native_data_type {
2347 #my ($self, $data_type) = @_;
2351 # Check if placeholders are supported at all
2352 sub _placeholders_supported {
2354 my $dbh = $self->_get_dbh;
2356 # some drivers provide a $dbh attribute (e.g. Sybase and $dbh->{syb_dynamic_supported})
2357 # but it is inaccurate more often than not
2359 local $dbh->{PrintError} = 0;
2360 local $dbh->{RaiseError} = 1;
2361 $dbh->do('select ?', {}, 1);
2366 # Check if placeholders bound to non-string types throw exceptions
2368 sub _typeless_placeholders_supported {
2370 my $dbh = $self->_get_dbh;
2373 local $dbh->{PrintError} = 0;
2374 local $dbh->{RaiseError} = 1;
2375 # this specifically tests a bind that is NOT a string
2376 $dbh->do('select 1 where 1 = ?', {}, 1);
2383 Returns the database driver name.
2388 shift->_get_dbh->{Driver}->{Name};
2391 =head2 bind_attribute_by_data_type
2393 Given a datatype from column info, returns a database specific bind
2394 attribute for C<< $dbh->bind_param($val,$attribute) >> or nothing if we will
2395 let the database planner just handle it.
2397 Generally only needed for special case column types, like bytea in postgres.
2401 sub bind_attribute_by_data_type {
2405 =head2 is_datatype_numeric
2407 Given a datatype from column_info, returns a boolean value indicating if
2408 the current RDBMS considers it a numeric value. This controls how
2409 L<DBIx::Class::Row/set_column> decides whether to mark the column as
2410 dirty - when the datatype is deemed numeric a C<< != >> comparison will
2411 be performed instead of the usual C<eq>.
2415 sub is_datatype_numeric {
2416 my ($self, $dt) = @_;
2418 return 0 unless $dt;
2420 return $dt =~ /^ (?:
2421 numeric | int(?:eger)? | (?:tiny|small|medium|big)int | dec(?:imal)? | real | float | double (?: \s+ precision)? | (?:big)?serial
2426 =head2 create_ddl_dir (EXPERIMENTAL)
2430 =item Arguments: $schema \@databases, $version, $directory, $preversion, \%sqlt_args
2434 Creates a SQL file based on the Schema, for each of the specified
2435 database engines in C<\@databases> in the given directory.
2436 (note: specify L<SQL::Translator> names, not L<DBI> driver names).
2438 Given a previous version number, this will also create a file containing
2439 the ALTER TABLE statements to transform the previous schema into the
2440 current one. Note that these statements may contain C<DROP TABLE> or
2441 C<DROP COLUMN> statements that can potentially destroy data.
2443 The file names are created using the C<ddl_filename> method below, please
2444 override this method in your schema if you would like a different file
2445 name format. For the ALTER file, the same format is used, replacing
2446 $version in the name with "$preversion-$version".
2448 See L<SQL::Translator/METHODS> for a list of values for C<\%sqlt_args>.
2449 The most common value for this would be C<< { add_drop_table => 1 } >>
2450 to have the SQL produced include a C<DROP TABLE> statement for each table
2451 created. For quoting purposes supply C<quote_table_names> and
2452 C<quote_field_names>.
2454 If no arguments are passed, then the following default values are assumed:
2458 =item databases - ['MySQL', 'SQLite', 'PostgreSQL']
2460 =item version - $schema->schema_version
2462 =item directory - './'
2464 =item preversion - <none>
2468 By default, C<\%sqlt_args> will have
2470 { add_drop_table => 1, ignore_constraint_names => 1, ignore_index_names => 1 }
2472 merged with the hash passed in. To disable any of those features, pass in a
2473 hashref like the following
2475 { ignore_constraint_names => 0, # ... other options }
2478 Note that this feature is currently EXPERIMENTAL and may not work correctly
2479 across all databases, or fully handle complex relationships.
2481 WARNING: Please check all SQL files created, before applying them.
2485 sub create_ddl_dir {
2486 my ($self, $schema, $databases, $version, $dir, $preversion, $sqltargs) = @_;
2488 if(!$dir || !-d $dir) {
2489 carp "No directory given, using ./\n";
2492 $databases ||= ['MySQL', 'SQLite', 'PostgreSQL'];
2493 $databases = [ $databases ] if(ref($databases) ne 'ARRAY');
2495 my $schema_version = $schema->schema_version || '1.x';
2496 $version ||= $schema_version;
2499 add_drop_table => 1,
2500 ignore_constraint_names => 1,
2501 ignore_index_names => 1,
2505 $self->throw_exception("Can't create a ddl file without SQL::Translator: " . $self->_sqlt_version_error)
2506 if !$self->_sqlt_version_ok;
2508 my $sqlt = SQL::Translator->new( $sqltargs );
2510 $sqlt->parser('SQL::Translator::Parser::DBIx::Class');
2511 my $sqlt_schema = $sqlt->translate({ data => $schema })
2512 or $self->throw_exception ($sqlt->error);
2514 foreach my $db (@$databases) {
2516 $sqlt->{schema} = $sqlt_schema;
2517 $sqlt->producer($db);
2520 my $filename = $schema->ddl_filename($db, $version, $dir);
2521 if (-e $filename && ($version eq $schema_version )) {
2522 # if we are dumping the current version, overwrite the DDL
2523 carp "Overwriting existing DDL file - $filename";
2527 my $output = $sqlt->translate;
2529 carp("Failed to translate to $db, skipping. (" . $sqlt->error . ")");
2532 if(!open($file, ">$filename")) {
2533 $self->throw_exception("Can't open $filename for writing ($!)");
2536 print $file $output;
2539 next unless ($preversion);
2541 require SQL::Translator::Diff;
2543 my $prefilename = $schema->ddl_filename($db, $preversion, $dir);
2544 if(!-e $prefilename) {
2545 carp("No previous schema file found ($prefilename)");
2549 my $difffile = $schema->ddl_filename($db, $version, $dir, $preversion);
2551 carp("Overwriting existing diff file - $difffile");
2557 my $t = SQL::Translator->new($sqltargs);
2562 or $self->throw_exception ($t->error);
2564 my $out = $t->translate( $prefilename )
2565 or $self->throw_exception ($t->error);
2567 $source_schema = $t->schema;
2569 $source_schema->name( $prefilename )
2570 unless ( $source_schema->name );
2573 # The "new" style of producers have sane normalization and can support
2574 # diffing a SQL file against a DBIC->SQLT schema. Old style ones don't
2575 # And we have to diff parsed SQL against parsed SQL.
2576 my $dest_schema = $sqlt_schema;
2578 unless ( "SQL::Translator::Producer::$db"->can('preprocess_schema') ) {
2579 my $t = SQL::Translator->new($sqltargs);
2584 or $self->throw_exception ($t->error);
2586 my $out = $t->translate( $filename )
2587 or $self->throw_exception ($t->error);
2589 $dest_schema = $t->schema;
2591 $dest_schema->name( $filename )
2592 unless $dest_schema->name;
2595 my $diff = SQL::Translator::Diff::schema_diff($source_schema, $db,
2599 if(!open $file, ">$difffile") {
2600 $self->throw_exception("Can't write to $difffile ($!)");
2608 =head2 deployment_statements
2612 =item Arguments: $schema, $type, $version, $directory, $sqlt_args
2616 Returns the statements used by L</deploy> and L<DBIx::Class::Schema/deploy>.
2618 The L<SQL::Translator> (not L<DBI>) database driver name can be explicitly
2619 provided in C<$type>, otherwise the result of L</sqlt_type> is used as default.
2621 C<$directory> is used to return statements from files in a previously created
2622 L</create_ddl_dir> directory and is optional. The filenames are constructed
2623 from L<DBIx::Class::Schema/ddl_filename>, the schema name and the C<$version>.
2625 If no C<$directory> is specified then the statements are constructed on the
2626 fly using L<SQL::Translator> and C<$version> is ignored.
2628 See L<SQL::Translator/METHODS> for a list of values for C<$sqlt_args>.
2632 sub deployment_statements {
2633 my ($self, $schema, $type, $version, $dir, $sqltargs) = @_;
2634 $type ||= $self->sqlt_type;
2635 $version ||= $schema->schema_version || '1.x';
2637 my $filename = $schema->ddl_filename($type, $version, $dir);
2641 open($file, "<$filename")
2642 or $self->throw_exception("Can't open $filename ($!)");
2645 return join('', @rows);
2648 $self->throw_exception("Can't deploy without either SQL::Translator or a ddl_dir: " . $self->_sqlt_version_error )
2649 if !$self->_sqlt_version_ok;
2651 # sources needs to be a parser arg, but for simplicty allow at top level
2653 $sqltargs->{parser_args}{sources} = delete $sqltargs->{sources}
2654 if exists $sqltargs->{sources};
2656 my $tr = SQL::Translator->new(
2657 producer => "SQL::Translator::Producer::${type}",
2659 parser => 'SQL::Translator::Parser::DBIx::Class',
2663 my $ret = $tr->translate
2664 or $self->throw_exception( 'Unable to produce deployment statements: ' . $tr->error);
2670 my ($self, $schema, $type, $sqltargs, $dir) = @_;
2673 return if($line =~ /^--/);
2675 # next if($line =~ /^DROP/m);
2676 return if($line =~ /^BEGIN TRANSACTION/m);
2677 return if($line =~ /^COMMIT/m);
2678 return if $line =~ /^\s+$/; # skip whitespace only
2679 $self->_query_start($line);
2681 # do a dbh_do cycle here, as we need some error checking in
2682 # place (even though we will ignore errors)
2683 $self->dbh_do (sub { $_[1]->do($line) });
2686 carp qq{$@ (running "${line}")};
2688 $self->_query_end($line);
2690 my @statements = $self->deployment_statements($schema, $type, undef, $dir, { %{ $sqltargs || {} }, no_comments => 1 } );
2691 if (@statements > 1) {
2692 foreach my $statement (@statements) {
2693 $deploy->( $statement );
2696 elsif (@statements == 1) {
2697 foreach my $line ( split(";\n", $statements[0])) {
2703 =head2 datetime_parser
2705 Returns the datetime parser class
2709 sub datetime_parser {
2711 return $self->{datetime_parser} ||= do {
2712 $self->build_datetime_parser(@_);
2716 =head2 datetime_parser_type
2718 Defines (returns) the datetime parser class - currently hardwired to
2719 L<DateTime::Format::MySQL>
2723 sub datetime_parser_type { "DateTime::Format::MySQL"; }
2725 =head2 build_datetime_parser
2727 See L</datetime_parser>
2731 sub build_datetime_parser {
2733 my $type = $self->datetime_parser_type(@_);
2734 $self->ensure_class_loaded ($type);
2739 =head2 is_replicating
2741 A boolean that reports if a particular L<DBIx::Class::Storage::DBI> is set to
2742 replicate from a master database. Default is undef, which is the result
2743 returned by databases that don't support replication.
2747 sub is_replicating {
2752 =head2 lag_behind_master
2754 Returns a number that represents a certain amount of lag behind a master db
2755 when a given storage is replicating. The number is database dependent, but
2756 starts at zero and increases with the amount of lag. Default in undef
2760 sub lag_behind_master {
2764 # SQLT version handling
2766 my $_sqlt_version_ok; # private
2767 my $_sqlt_version_error; # private
2769 sub _sqlt_version_ok {
2770 if (!defined $_sqlt_version_ok) {
2771 eval "use SQL::Translator $minimum_sqlt_version";
2773 $_sqlt_version_ok = 0;
2774 $_sqlt_version_error = $@;
2777 $_sqlt_version_ok = 1;
2780 return $_sqlt_version_ok;
2783 sub _sqlt_version_error {
2784 shift->_sqlt_version_ok unless defined $_sqlt_version_ok;
2785 return $_sqlt_version_error;
2788 sub _sqlt_minimum_version { $minimum_sqlt_version };
2794 $self->_verify_pid if $self->_dbh;
2796 # some databases need this to stop spewing warnings
2797 if (my $dbh = $self->_dbh) {
2799 eval { $dbh->disconnect };
2809 =head2 DBIx::Class and AutoCommit
2811 DBIx::Class can do some wonderful magic with handling exceptions,
2812 disconnections, and transactions when you use C<< AutoCommit => 1 >>
2813 (the default) combined with C<txn_do> for transaction support.
2815 If you set C<< AutoCommit => 0 >> in your connect info, then you are always
2816 in an assumed transaction between commits, and you're telling us you'd
2817 like to manage that manually. A lot of the magic protections offered by
2818 this module will go away. We can't protect you from exceptions due to database
2819 disconnects because we don't know anything about how to restart your
2820 transactions. You're on your own for handling all sorts of exceptional
2821 cases if you choose the C<< AutoCommit => 0 >> path, just as you would
2827 Matt S. Trout <mst@shadowcatsystems.co.uk>
2829 Andy Grundman <andy@hybridized.org>
2833 You may distribute this code under the same terms as Perl itself.