package DBIx::Class::Storage::DBI;
# -*- mode: cperl; cperl-indent-level: 2 -*-
-use base 'DBIx::Class::Storage';
-
use strict;
use warnings;
+
+use base 'DBIx::Class::Storage';
+use mro 'c3';
+
use Carp::Clan qw/^DBIx::Class/;
use DBI;
use DBIx::Class::Storage::DBI::Cursor;
use List::Util();
__PACKAGE__->mk_group_accessors('simple' =>
- qw/_connect_info _dbi_connect_info _dbh _sql_maker _sql_maker_opts
- _conn_pid _conn_tid transaction_depth _dbh_autocommit savepoints/
+ qw/_connect_info _dbi_connect_info _dbh _sql_maker _sql_maker_opts _conn_pid
+ _conn_tid transaction_depth _dbh_autocommit _driver_determined savepoints/
);
# the values for these accessors are picked out (and deleted) from
# the attribute hashref passed to connect_info
my @storage_options = qw/
- on_connect_do on_disconnect_do disable_sth_caching unsafe auto_savepoint
+ on_connect_call on_disconnect_call on_connect_do on_disconnect_do
+ disable_sth_caching unsafe auto_savepoint
/;
__PACKAGE__->mk_group_accessors('simple' => @storage_options);
Note, this only runs if you explicitly call L</disconnect> on the
storage object.
+=item on_connect_call
+
+A more generalized form of L</on_connect_do> that calls the specified
+C<connect_call_METHOD> methods in your storage driver.
+
+ on_connect_do => 'select 1'
+
+is equivalent to:
+
+ on_connect_call => [ [ do_sql => 'select 1' ] ]
+
+Its values may contain:
+
+=over
+
+=item a scalar
+
+Will call the C<connect_call_METHOD> method.
+
+=item a code reference
+
+Will execute C<< $code->($storage) >>
+
+=item an array reference
+
+Each value can be a method name or code reference.
+
+=item an array of arrays
+
+For each array, the first item is taken to be the C<connect_call_> method name
+or code reference, and the rest are parameters to it.
+
+=back
+
+Some predefined storage methods you may use:
+
+=over
+
+=item do_sql
+
+Executes a SQL string or a code reference that returns a SQL string. This is
+what L</on_connect_do> and L</on_disconnect_do> use.
+
+It can take:
+
+=over
+
+=item a scalar
+
+Will execute the scalar as SQL.
+
+=item an arrayref
+
+Taken to be arguments to L<DBI/do>, the SQL string optionally followed by the
+attributes hashref and bind values.
+
+=item a code reference
+
+Will execute C<< $code->($storage) >> and execute the return array refs as
+above.
+
+=back
+
+=item datetime_setup
+
+Execute any statements necessary to initialize the database session to return
+and accept datetime/timestamp values used with
+L<DBIx::Class::InflateColumn::DateTime>.
+
+Only necessary for some databases, see your specific storage driver for
+implementation details.
+
+=back
+
+=item on_disconnect_call
+
+Takes arguments in the same form as L</on_connect_call> and executes them
+immediately before disconnecting from the database.
+
+Calls the C<disconnect_call_METHOD> methods as opposed to the
+C<connect_call_METHOD> methods called by L</on_connect_call>.
+
+Note, this only runs if you explicitly call L</disconnect> on the
+storage object.
+
=item disable_sth_caching
If set to a true value, this option will disable the caching of
}
}
- %attrs = () if (ref $args[0] eq 'CODE'); # _connect() never looks past $args[0] in this case
+ if (ref $args[0] eq 'CODE') {
+ # _connect() never looks past $args[0] in this case
+ %attrs = ()
+ } else {
+ %attrs = (
+ %{ $self->_default_dbi_connect_attributes || {} },
+ %attrs,
+ );
+ }
$self->_dbi_connect_info([@args, keys %attrs ? \%attrs : ()]);
$self->_connect_info;
}
+sub _default_dbi_connect_attributes {
+ return { AutoCommit => 1 };
+}
+
=head2 on_connect_do
This method is deprecated in favour of setting via L</connect_info>.
+=cut
+
+=head2 on_disconnect_do
+
+This method is deprecated in favour of setting via L</connect_info>.
+
+=cut
+
+sub _parse_connect_do {
+ my ($self, $type) = @_;
+
+ my $val = $self->$type;
+ return () if not defined $val;
+
+ my @res;
+
+ if (not ref($val)) {
+ push @res, [ 'do_sql', $val ];
+ } elsif (ref($val) eq 'CODE') {
+ push @res, $val;
+ } elsif (ref($val) eq 'ARRAY') {
+ push @res, map { [ 'do_sql', $_ ] } @$val;
+ } else {
+ $self->throw_exception("Invalid type for $type: ".ref($val));
+ }
+
+ return \@res;
+}
=head2 dbh_do
my $exception = $@;
if(!$exception) { return $want_array ? @result : $result[0] }
- if($tried++ > 0 || $self->connected) {
+ if($tried++ || $self->connected) {
eval { $self->txn_rollback };
my $rollback_exception = $@;
if($rollback_exception) {
sub disconnect {
my ($self) = @_;
- if( $self->connected ) {
- my $connection_do = $self->on_disconnect_do;
- $self->_do_connection_actions($connection_do) if ref($connection_do);
+ if( $self->_dbh ) {
+ my @actions;
+
+ push @actions, ( $self->on_disconnect_call || () );
+ push @actions, $self->_parse_connect_do ('on_disconnect_do');
+
+ $self->_do_connection_actions(disconnect_call_ => $_) for @actions;
+
+ $self->_dbh_rollback unless $self->_dbh_autocommit;
- $self->_dbh->rollback unless $self->_dbh_autocommit;
$self->_dbh->disconnect;
$self->_dbh(undef);
$self->{_dbh_gen}++;
$sub->();
}
+=head2 connected
+
+=over
+
+=item Arguments: none
+
+=item Return Value: 1|0
+
+=back
+
+Verifies that the the current database handle is active and ready to execute
+an SQL statement (i.e. the connection did not get stale, server is still
+answering, etc.) This method is used internally by L</dbh>.
+
+=cut
+
sub connected {
my ($self) = @_;
$self->_verify_pid;
return 0 if !$self->_dbh;
}
- return ($dbh->FETCH('Active') && $dbh->ping);
+ return ($dbh->FETCH('Active') && $self->_ping);
}
return 0;
}
+sub _ping {
+ my $self = shift;
+
+ my $dbh = $self->_dbh or return 0;
+
+ return $dbh->ping;
+}
+
# handle pid changes correctly
# NOTE: assumes $self->_dbh is a valid $dbh
sub _verify_pid {
=head2 dbh
-Returns the dbh - a data base handle of class L<DBI>.
+Returns a C<$dbh> - a data base handle of class L<DBI>. The returned handle
+is guaranteed to be healthy by implicitly calling L</connected>, and if
+necessary performing a reconnection before returning.
=cut
sub dbh {
my ($self) = @_;
- $self->ensure_connected;
+ if (not $self->_dbh) {
+ $self->_populate_dbh;
+ } else {
+ $self->ensure_connected;
+ }
+ return $self->_dbh;
+}
+
+=head2 last_dbh
+
+This returns the B<last> available C<$dbh> if any, or attempts to
+connect and returns the resulting handle. This method differs from
+L</dbh> by not validating if a preexisting handle is still healthy
+via L</connected>. Make sure you take appropriate precautions
+when using this method, as the C<$dbh> may be useless at this point.
+
+=cut
+
+sub last_dbh {
+ my $self = shift;
+ $self->_populate_dbh unless $self->_dbh;
return $self->_dbh;
}
sub _sql_maker_args {
my ($self) = @_;
- return ( bindtype=>'columns', array_datatypes => 1, limit_dialect => $self->dbh, %{$self->_sql_maker_opts} );
+ return (
+ bindtype=>'columns',
+ array_datatypes => 1,
+ limit_dialect => $self->last_dbh,
+ %{$self->_sql_maker_opts}
+ );
}
sub sql_maker {
sub _populate_dbh {
my ($self) = @_;
+
my @info = @{$self->_dbi_connect_info || []};
$self->_dbh($self->_connect(@info));
# there is no transaction in progress by definition
$self->{transaction_depth} = $self->_dbh_autocommit ? 0 : 1;
- my $connection_do = $self->on_connect_do;
- $self->_do_connection_actions($connection_do) if $connection_do;
+ $self->_run_connection_actions unless $self->{_in_determine_driver};
+}
+
+sub _run_connection_actions {
+ my $self = shift;
+ my @actions;
+
+ push @actions, ( $self->on_connect_call || () );
+ push @actions, $self->_parse_connect_do ('on_connect_do');
+
+ $self->_do_connection_actions(connect_call_ => $_) for @actions;
}
sub _determine_driver {
my ($self) = @_;
- if (ref $self eq 'DBIx::Class::Storage::DBI') {
- my $driver;
+ if (not $self->_driver_determined) {
+ my $started_unconnected = 0;
+ local $self->{_in_determine_driver} = 1;
+
+ if (ref($self) eq __PACKAGE__) {
+ my $driver;
+ if ($self->_dbh) { # we are connected
+ $driver = $self->_dbh->{Driver}{Name};
+ } else {
+ # try to use dsn to not require being connected, the driver may still
+ # force a connection in _rebless to determine version
+ ($driver) = $self->_dbi_connect_info->[0] =~ /dbi:([^:]+):/i;
+ $started_unconnected = 1;
+ }
- if ($self->_dbh) { # we are connected
- $driver = $self->_dbh->{Driver}{Name};
- } else {
- # try to use dsn to not require being connected, the driver may still
- # force a connection in _rebless to determine version
- ($driver) = $self->_dbi_connect_info->[0] =~ /dbi:([^:]+):/i;
+ my $storage_class = "DBIx::Class::Storage::DBI::${driver}";
+ if ($self->load_optional_class($storage_class)) {
+ mro::set_mro($storage_class, 'c3');
+ bless $self, $storage_class;
+ $self->_rebless();
+ }
}
- if ($self->load_optional_class("DBIx::Class::Storage::DBI::${driver}")) {
- bless $self, "DBIx::Class::Storage::DBI::${driver}";
- $self->_rebless();
- }
+ $self->_driver_determined(1);
+
+ $self->_run_connection_actions
+ if $started_unconnected && defined $self->_dbh;
}
}
sub _do_connection_actions {
- my $self = shift;
- my $connection_do = shift;
-
- if (!ref $connection_do) {
- $self->_do_query($connection_do);
- }
- elsif (ref $connection_do eq 'ARRAY') {
- $self->_do_query($_) foreach @$connection_do;
- }
- elsif (ref $connection_do eq 'CODE') {
- $connection_do->($self);
- }
- else {
- $self->throw_exception (sprintf ("Don't know how to process conection actions of type '%s'", ref $connection_do) );
+ my $self = shift;
+ my $method_prefix = shift;
+ my $call = shift;
+
+ if (not ref($call)) {
+ my $method = $method_prefix . $call;
+ $self->$method(@_);
+ } elsif (ref($call) eq 'CODE') {
+ $self->$call(@_);
+ } elsif (ref($call) eq 'ARRAY') {
+ if (ref($call->[0]) ne 'ARRAY') {
+ $self->_do_connection_actions($method_prefix, $_) for @$call;
+ } else {
+ $self->_do_connection_actions($method_prefix, @$_) for @$call;
+ }
+ } else {
+ $self->throw_exception (sprintf ("Don't know how to process conection actions of type '%s'", ref($call)) );
}
return $self;
}
+sub connect_call_do_sql {
+ my $self = shift;
+ $self->_do_query(@_);
+}
+
+sub disconnect_call_do_sql {
+ my $self = shift;
+ $self->_do_query(@_);
+}
+
+# override in db-specific backend when necessary
+sub connect_call_datetime_setup { 1 }
+
sub _do_query {
my ($self, $action) = @_;
sub txn_begin {
my $self = shift;
- $self->ensure_connected();
if($self->{transaction_depth} == 0) {
$self->debugobj->txn_begin()
if $self->debug;
- # this isn't ->_dbh-> because
- # we should reconnect on begin_work
- # for AutoCommit users
- $self->dbh->begin_work;
- } elsif ($self->auto_savepoint) {
+ $self->_dbh_begin_work;
+ }
+ elsif ($self->auto_savepoint) {
$self->svp_begin;
}
$self->{transaction_depth}++;
}
+sub _dbh_begin_work {
+ my $self = shift;
+ # being here implies we have AutoCommit => 1
+ # if the user is utilizing txn_do - good for
+ # him, otherwise we need to ensure that the
+ # $dbh is healthy on BEGIN
+ my $dbh_method = $self->{_in_dbh_do} ? '_dbh' : 'dbh';
+ $self->$dbh_method->begin_work;
+}
+
sub txn_commit {
my $self = shift;
if ($self->{transaction_depth} == 1) {
my $dbh = $self->_dbh;
$self->debugobj->txn_commit()
if ($self->debug);
- $dbh->commit;
+ $self->_dbh_commit;
$self->{transaction_depth} = 0
if $self->_dbh_autocommit;
}
}
}
+sub _dbh_commit {
+ my $self = shift;
+ $self->_dbh->commit;
+}
+
sub txn_rollback {
my $self = shift;
my $dbh = $self->_dbh;
if ($self->debug);
$self->{transaction_depth} = 0
if $self->_dbh_autocommit;
- $dbh->rollback;
+ $self->_dbh_rollback;
}
elsif($self->{transaction_depth} > 1) {
$self->{transaction_depth}--;
}
}
+sub _dbh_rollback {
+ my $self = shift;
+ $self->_dbh->rollback;
+}
+
# This used to be the top-half of _execute. It was split out to make it
# easier to override in NoBindVars without duping the rest. It takes up
# all of _execute's args, and emits $sql, @bind.
sub insert {
my ($self, $source, $to_insert) = @_;
+# redispatch to insert method of storage we reblessed into, if necessary
+ if (not $self->_driver_determined) {
+ $self->_determine_driver;
+ goto $self->can('insert');
+ }
+
my $ident = $source->from;
my $bind_attributes = $self->source_bind_attributes($source);
my $updated_cols = {};
- $self->ensure_connected;
foreach my $col ( $source->columns ) {
if ( !defined $to_insert->{$col} ) {
my $col_info = $source->column_info($col);
if ( $col_info->{auto_nextval} ) {
- $updated_cols->{$col} = $to_insert->{$col} = $self->_sequence_fetch( 'nextval', $col_info->{sequence} || $self->_dbh_get_autoinc_seq($self->dbh, $source) );
+ $updated_cols->{$col} = $to_insert->{$col} = $self->_sequence_fetch(
+ 'nextval',
+ $col_info->{sequence} ||
+ $self->_dbh_get_autoinc_seq($self->last_dbh, $source)
+ );
}
}
}
@colvalues{@$cols} = (0..$#$cols);
my ($sql, @bind) = $self->sql_maker->insert($table, \%colvalues);
+ $self->_determine_driver;
+
$self->_query_start( $sql, @bind );
my $sth = $self->sth($sql);
sub update {
my $self = shift @_;
my $source = shift @_;
+ $self->_determine_driver;
my $bind_attributes = $self->source_bind_attributes($source);
return $self->_execute('update' => [], $source, $bind_attributes, @_);
sub delete {
my $self = shift @_;
my $source = shift @_;
-
+ $self->_determine_driver;
my $bind_attrs = $self->source_bind_attributes($source);
return $self->_execute('delete' => [], $source, $bind_attrs, @_);
}
sub _select_args {
- my ($self, $ident, $select, $condition, $attrs) = @_;
+ my ($self, $ident, $select, $where, $attrs) = @_;
- my $sql_maker = $self->sql_maker;
- $sql_maker->{_dbic_rs_attrs} = $attrs;
+ my ($alias2source, $rs_alias) = $self->_resolve_ident_sources ($ident);
- my $order = { map
- { $attrs->{$_} ? ( $_ => $attrs->{$_} ) : () }
- (qw/order_by group_by having _virtual_order_by/ )
+ my $sql_maker = $self->sql_maker;
+ $sql_maker->{_dbic_rs_attrs} = {
+ %$attrs,
+ select => $select,
+ from => $ident,
+ where => $where,
+ $rs_alias
+ ? ( _source_handle => $alias2source->{$rs_alias}->handle )
+ : ()
+ ,
};
-
+ # calculate bind_attrs before possible $ident mangling
my $bind_attrs = {};
-
- my $alias2source = $self->_resolve_ident_sources ($ident);
-
for my $alias (keys %$alias2source) {
my $bindtypes = $self->source_bind_attributes ($alias2source->{$alias}) || {};
for my $col (keys %$bindtypes) {
my $fqcn = join ('.', $alias, $col);
$bind_attrs->{$fqcn} = $bindtypes->{$col} if $bindtypes->{$col};
- # so that unqualified searches can be bound too
- $bind_attrs->{$col} = $bind_attrs->{$fqcn} if $alias eq 'me';
+ # Unqialified column names are nice, but at the same time can be
+ # rather ambiguous. What we do here is basically go along with
+ # the loop, adding an unqualified column slot to $bind_attrs,
+ # alongside the fully qualified name. As soon as we encounter
+ # another column by that name (which would imply another table)
+ # we unset the unqualified slot and never add any info to it
+ # to avoid erroneous type binding. If this happens the users
+ # only choice will be to fully qualify his column name
+
+ if (exists $bind_attrs->{$col}) {
+ $bind_attrs->{$col} = {};
+ }
+ else {
+ $bind_attrs->{$col} = $bind_attrs->{$fqcn};
+ }
}
}
- # This would be the point to deflate anything found in $condition
+ # adjust limits
+ if (
+ $attrs->{software_limit}
+ ||
+ $sql_maker->_default_limit_syntax eq "GenericSubQ"
+ ) {
+ $attrs->{software_limit} = 1;
+ }
+ else {
+ $self->throw_exception("rows attribute must be positive if present")
+ if (defined($attrs->{rows}) && !($attrs->{rows} > 0));
+
+ # MySQL actually recommends this approach. I cringe.
+ $attrs->{rows} = 2**48 if not defined $attrs->{rows} and defined $attrs->{offset};
+ }
+
+ my @limit;
+
+ # see if we need to tear the prefetch apart (either limited has_many or grouped prefetch)
+ # otherwise delegate the limiting to the storage, unless software limit was requested
+ if (
+ ( $attrs->{rows} && keys %{$attrs->{collapse}} )
+ ||
+ ( $attrs->{group_by} && @{$attrs->{group_by}} &&
+ $attrs->{_prefetch_select} && @{$attrs->{_prefetch_select}} )
+ ) {
+ ($ident, $select, $where, $attrs)
+ = $self->_adjust_select_args_for_complex_prefetch ($ident, $select, $where, $attrs);
+ }
+ elsif (! $attrs->{software_limit} ) {
+ push @limit, $attrs->{rows}, $attrs->{offset};
+ }
+
+###
+ # This would be the point to deflate anything found in $where
# (and leave $attrs->{bind} intact). Problem is - inflators historically
# expect a row object. And all we have is a resultsource (it is trivial
# to extract deflator coderefs via $alias2source above).
#
# I don't see a way forward other than changing the way deflators are
# invoked, and that's just bad...
+###
- my @args = ('select', $attrs->{bind}, $ident, $bind_attrs, $select, $condition, $order);
- if ($attrs->{software_limit} ||
- $sql_maker->_default_limit_syntax eq "GenericSubQ") {
- $attrs->{software_limit} = 1;
- } else {
- $self->throw_exception("rows attribute must be positive if present")
- if (defined($attrs->{rows}) && !($attrs->{rows} > 0));
+ my $order = { map
+ { $attrs->{$_} ? ( $_ => $attrs->{$_} ) : () }
+ (qw/order_by group_by having/ )
+ };
- # MySQL actually recommends this approach. I cringe.
- $attrs->{rows} = 2**48 if not defined $attrs->{rows} and defined $attrs->{offset};
- push @args, $attrs->{rows}, $attrs->{offset};
+ return ('select', $attrs->{bind}, $ident, $bind_attrs, $select, $where, $order, @limit);
+}
+
+#
+# This is the code producing joined subqueries like:
+# SELECT me.*, other.* FROM ( SELECT me.* FROM ... ) JOIN other ON ...
+#
+sub _adjust_select_args_for_complex_prefetch {
+ my ($self, $from, $select, $where, $attrs) = @_;
+
+ $self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute')
+ if (ref $from ne 'ARRAY');
+
+ # copies for mangling
+ $from = [ @$from ];
+ $select = [ @$select ];
+ $attrs = { %$attrs };
+
+ # separate attributes
+ my $sub_attrs = { %$attrs };
+ delete $attrs->{$_} for qw/where bind rows offset group_by having/;
+ delete $sub_attrs->{$_} for qw/for collapse _prefetch_select _collapse_order_by select as/;
+
+ my $select_root_alias = $attrs->{alias};
+ my $sql_maker = $self->sql_maker;
+
+ # create subquery select list - consider only stuff *not* brought in by the prefetch
+ my $sub_select = [];
+ my $sub_group_by;
+ for my $i (0 .. @{$attrs->{select}} - @{$attrs->{_prefetch_select}} - 1) {
+ my $sel = $attrs->{select}[$i];
+
+ # alias any functions to the dbic-side 'as' label
+ # adjust the outer select accordingly
+ if (ref $sel eq 'HASH' && !$sel->{-select}) {
+ $sel = { -select => $sel, -as => $attrs->{as}[$i] };
+ $select->[$i] = join ('.', $attrs->{alias}, ($attrs->{as}[$i] || "select_$i") );
+ }
+
+ push @$sub_select, $sel;
+ }
+
+ # bring over all non-collapse-induced order_by into the inner query (if any)
+ # the outer one will have to keep them all
+ delete $sub_attrs->{order_by};
+ if (my $ord_cnt = @{$attrs->{order_by}} - @{$attrs->{_collapse_order_by}} ) {
+ $sub_attrs->{order_by} = [
+ @{$attrs->{order_by}}[ 0 .. $ord_cnt - 1]
+ ];
+ }
+
+ # mangle {from}, keep in mind that $from is "headless" from here on
+ my $join_root = shift @$from;
+
+ my %inner_joins;
+ my %join_info = map { $_->[0]{-alias} => $_->[0] } (@$from);
+
+ # in complex search_related chains $select_root_alias may *not* be
+ # 'me' so always include it in the inner join
+ $inner_joins{$select_root_alias} = 1 if ($join_root->{-alias} ne $select_root_alias);
+
+
+ # decide which parts of the join will remain on the inside
+ #
+ # this is not a very viable optimisation, but it was written
+ # before I realised this, so might as well remain. We can throw
+ # away _any_ branches of the join tree that are:
+ # 1) not mentioned in the condition/order
+ # 2) left-join leaves (or left-join leaf chains)
+ # Most of the join conditions will not satisfy this, but for real
+ # complex queries some might, and we might make some RDBMS happy.
+ #
+ #
+ # since we do not have introspectable SQLA, we fall back to ugly
+ # scanning of raw SQL for WHERE, and for pieces of ORDER BY
+ # in order to determine what goes into %inner_joins
+ # It may not be very efficient, but it's a reasonable stop-gap
+ {
+ # produce stuff unquoted, so it can be scanned
+ local $sql_maker->{quote_char};
+ my $sep = $self->_sql_maker_opts->{name_sep} || '.';
+ $sep = "\Q$sep\E";
+
+ my @order_by = (map
+ { ref $_ ? $_->[0] : $_ }
+ $sql_maker->_order_by_chunks ($sub_attrs->{order_by})
+ );
+
+ my $where_sql = $sql_maker->where ($where);
+ my $select_sql = $sql_maker->_recurse_fields ($sub_select);
+
+ # sort needed joins
+ for my $alias (keys %join_info) {
+
+ # any table alias found on a column name in where or order_by
+ # gets included in %inner_joins
+ # Also any parent joins that are needed to reach this particular alias
+ for my $piece ($select_sql, $where_sql, @order_by ) {
+ if ($piece =~ /\b $alias $sep/x) {
+ $inner_joins{$alias} = 1;
+ }
+ }
+ }
+ }
+
+ # scan for non-leaf/non-left joins and mark as needed
+ # also mark all ancestor joins that are needed to reach this particular alias
+ # (e.g. join => { cds => 'tracks' } - tracks will bring cds too )
+ #
+ # traverse by the size of the -join_path i.e. reverse depth first
+ for my $alias (sort { @{$join_info{$b}{-join_path}} <=> @{$join_info{$a}{-join_path}} } (keys %join_info) ) {
+
+ my $j = $join_info{$alias};
+ $inner_joins{$alias} = 1 if (! $j->{-join_type} || ($j->{-join_type} !~ /^left$/i) );
+
+ if ($inner_joins{$alias}) {
+ $inner_joins{$_} = 1 for (@{$j->{-join_path}});
+ }
+ }
+
+ # construct the inner $from for the subquery
+ my $inner_from = [ $join_root ];
+ for my $j (@$from) {
+ push @$inner_from, $j if $inner_joins{$j->[0]{-alias}};
+ }
+
+ # if a multi-type join was needed in the subquery ("multi" is indicated by
+ # presence in {collapse}) - add a group_by to simulate the collapse in the subq
+ unless ($sub_attrs->{group_by}) {
+ for my $alias (keys %inner_joins) {
+
+ # the dot comes from some weirdness in collapse
+ # remove after the rewrite
+ if ($attrs->{collapse}{".$alias"}) {
+ $sub_attrs->{group_by} ||= $sub_select;
+ last;
+ }
+ }
+ }
+
+ # generate the subquery
+ my $subq = $self->_select_args_to_query (
+ $inner_from,
+ $sub_select,
+ $where,
+ $sub_attrs
+ );
+ my $subq_joinspec = {
+ -alias => $select_root_alias,
+ -source_handle => $join_root->{-source_handle},
+ $select_root_alias => $subq,
+ };
+
+ # Generate a new from (really just replace the join slot with the subquery)
+ # Before we would start the outer chain from the subquery itself (i.e.
+ # SELECT ... FROM (SELECT ... ) alias JOIN ..., but this turned out to be
+ # a bad idea for search_related, as the root of the chain was effectively
+ # lost (i.e. $artist_rs->search_related ('cds'... ) would result in alias
+ # of 'cds', which would prevent from doing things like order_by artist.*)
+ # See t/prefetch/via_search_related.t for a better idea
+ my @outer_from;
+ if ($join_root->{-alias} eq $select_root_alias) { # just swap the root part and we're done
+ @outer_from = (
+ $subq_joinspec,
+ @$from,
+ )
+ }
+ else { # this is trickier
+ @outer_from = ($join_root);
+
+ for my $j (@$from) {
+ if ($j->[0]{-alias} eq $select_root_alias) {
+ push @outer_from, [
+ $subq_joinspec,
+ @{$j}[1 .. $#$j],
+ ];
+ }
+ else {
+ push @outer_from, $j;
+ }
+ }
}
- return @args;
+
+ # This is totally horrific - the $where ends up in both the inner and outer query
+ # Unfortunately not much can be done until SQLA2 introspection arrives, and even
+ # then if where conditions apply to the *right* side of the prefetch, you may have
+ # to both filter the inner select (e.g. to apply a limit) and then have to re-filter
+ # the outer select to exclude joins you didin't want in the first place
+ #
+ # OTOH it can be seen as a plus: <ash> (notes that this query would make a DBA cry ;)
+ return (\@outer_from, $select, $where, $attrs);
}
sub _resolve_ident_sources {
my ($self, $ident) = @_;
my $alias2source = {};
+ my $rs_alias;
# the reason this is so contrived is that $ident may be a {from}
# structure, specifying multiple tables to join
if ( Scalar::Util::blessed($ident) && $ident->isa("DBIx::Class::ResultSource") ) {
# this is compat mode for insert/update/delete which do not deal with aliases
$alias2source->{me} = $ident;
+ $rs_alias = 'me';
}
elsif (ref $ident eq 'ARRAY') {
my $tabinfo;
if (ref $_ eq 'HASH') {
$tabinfo = $_;
+ $rs_alias = $tabinfo->{-alias};
}
if (ref $_ eq 'ARRAY' and ref $_->[0] eq 'HASH') {
$tabinfo = $_->[0];
}
}
- return $alias2source;
+ return ($alias2source, $rs_alias);
}
# Takes $ident, \@column_names
# also note: this adds -result_source => $rsrc to the column info
#
# usage:
-# my $col_sources = $self->_resolve_column_info($ident, [map $_->[0], @{$bind}]);
+# my $col_sources = $self->_resolve_column_info($ident, @column_names);
sub _resolve_column_info {
my ($self, $ident, $colnames) = @_;
- my $alias2src = $self->_resolve_ident_sources($ident);
- my $name_sep = $self->_sql_maker_opts->{name_sep} || '.';
- my %return;
- foreach my $col (@{$colnames}) {
- $col =~ m/^([^\Q${name_sep}\E]*)\Q${name_sep}\E/;
- my $alias = $1 || 'me';
- my $rsrc = $alias2src->{$alias};
- $return{$col} = $rsrc && { %{$rsrc->column_info($col)}, -result_source => $rsrc };
- }
- return \%return;
-}
-
-sub count {
- my ($self, $source, $attrs) = @_;
-
- my $tmp_attrs = { %$attrs };
-
- # take off any pagers, record_filter is cdbi, and no point of ordering a count
- delete $tmp_attrs->{$_} for (qw/select as rows offset page order_by record_filter/);
+ my ($alias2src, $root_alias) = $self->_resolve_ident_sources($ident);
- # overwrite the selector
- $tmp_attrs->{select} = { count => '*' };
+ my $sep = $self->_sql_maker_opts->{name_sep} || '.';
+ $sep = "\Q$sep\E";
- my $tmp_rs = $source->resultset_class->new($source, $tmp_attrs);
- my ($count) = $tmp_rs->cursor->next;
+ my (%return, %seen_cols);
- # if the offset/rows attributes are still present, we did not use
- # a subquery, so we need to make the calculations in software
- $count -= $attrs->{offset} if $attrs->{offset};
- $count = $attrs->{rows} if $attrs->{rows} and $attrs->{rows} < $count;
- $count = 0 if ($count < 0);
-
- return $count;
-}
-
-sub count_grouped {
- my ($self, $source, $attrs) = @_;
+ # compile a global list of column names, to be able to properly
+ # disambiguate unqualified column names (if at all possible)
+ for my $alias (keys %$alias2src) {
+ my $rsrc = $alias2src->{$alias};
+ for my $colname ($rsrc->columns) {
+ push @{$seen_cols{$colname}}, $alias;
+ }
+ }
- # copy for the subquery, we need to do some adjustments to it too
- my $sub_attrs = { %$attrs };
+ COLUMN:
+ foreach my $col (@$colnames) {
+ my ($alias, $colname) = $col =~ m/^ (?: ([^$sep]+) $sep)? (.+) $/x;
- # these can not go in the subquery, and there is no point of ordering it
- delete $sub_attrs->{$_} for qw/prefetch collapse select as order_by/;
+ unless ($alias) {
+ # see if the column was seen exactly once (so we know which rsrc it came from)
+ if ($seen_cols{$colname} and @{$seen_cols{$colname}} == 1) {
+ $alias = $seen_cols{$colname}[0];
+ }
+ else {
+ next COLUMN;
+ }
+ }
- # if we prefetch, we group_by primary keys only as this is what we would get out of the rs via ->next/->all
- # simply deleting group_by suffices, as the code below will re-fill it
- # Note: we check $attrs, as $sub_attrs has collapse deleted
- if (ref $attrs->{collapse} and keys %{$attrs->{collapse}} ) {
- delete $sub_attrs->{group_by};
+ my $rsrc = $alias2src->{$alias};
+ $return{$col} = $rsrc && {
+ %{$rsrc->column_info($colname)},
+ -result_source => $rsrc,
+ -source_alias => $alias,
+ };
}
- $sub_attrs->{group_by} ||= [ map { "$attrs->{alias}.$_" } ($source->primary_columns) ];
- $sub_attrs->{select} = $self->_grouped_count_select ($source, $sub_attrs);
+ return \%return;
+}
- $attrs->{from} = [{
- count_subq => $source->resultset_class->new ($source, $sub_attrs )->as_query
- }];
+# Returns a counting SELECT for a simple count
+# query. Abstracted so that a storage could override
+# this to { count => 'firstcol' } or whatever makes
+# sense as a performance optimization
+sub _count_select {
+ #my ($self, $source, $rs_attrs) = @_;
+ return { count => '*' };
+}
- # the subquery replaces this
- delete $attrs->{$_} for qw/where bind prefetch collapse group_by having having_bind rows offset page pager/;
+# Returns a SELECT which will end up in the subselect
+# There may or may not be a group_by, as the subquery
+# might have been called to accomodate a limit
+#
+# Most databases would be happy with whatever ends up
+# here, but some choke in various ways.
+#
+sub _subq_count_select {
+ my ($self, $source, $rs_attrs) = @_;
+ return $rs_attrs->{group_by} if $rs_attrs->{group_by};
- return $self->count ($source, $attrs);
+ my @pcols = map { join '.', $rs_attrs->{alias}, $_ } ($source->primary_columns);
+ return @pcols ? \@pcols : [ 1 ];
}
#
-# Returns a SELECT to go with a supplied GROUP BY
-# (caled by count_grouped so a group_by is present)
-# Most databases expect them to match, but some
-# choke in various ways.
+# Returns an ordered list of column names before they are used
+# in a SELECT statement. By default simply returns the list
+# passed in.
#
-sub _grouped_count_select {
- my ($self, $source, $rs_args) = @_;
- return $rs_args->{group_by};
+# This may be overridden in a specific storage when there are
+# requirements such as moving BLOB columns to the end of the
+# SELECT list.
+sub _order_select_columns {
+ #my ($self, $source, $columns) = @_;
+ return @{$_[2]};
}
+
+
+
sub source_bind_attributes {
my ($self, $source) = @_;
=cut
-sub sqlt_type { shift->dbh->{Driver}->{Name} }
+sub sqlt_type { shift->last_dbh->{Driver}->{Name} }
=head2 bind_attribute_by_data_type
sub deployment_statements {
my ($self, $schema, $type, $version, $dir, $sqltargs) = @_;
# Need to be connected to get the correct sqlt_type
- $self->ensure_connected() unless $type;
+ $self->last_dbh() unless $type;
$type ||= $self->sqlt_type;
$version ||= $schema->schema_version || '1.x';
$dir ||= './';
return if $line =~ /^\s+$/; # skip whitespace only
$self->_query_start($line);
eval {
- $self->dbh->do($line); # shouldn't be using ->dbh ?
+ # a previous error may invalidate $dbh - thus we need to use dbh()
+ # to guarantee a healthy $dbh (this is temporary until we get
+ # proper error handling on deploy() )
+ $self->dbh->do($line);
};
if ($@) {
carp qq{$@ (running "${line}")};
sub datetime_parser {
my $self = shift;
return $self->{datetime_parser} ||= do {
- $self->ensure_connected;
+ $self->last_dbh;
$self->build_datetime_parser(@_);
};
}
DBIx::Class can do some wonderful magic with handling exceptions,
disconnections, and transactions when you use C<< AutoCommit => 1 >>
-combined with C<txn_do> for transaction support.
+(the default) combined with C<txn_do> for transaction support.
If you set C<< AutoCommit => 0 >> in your connect info, then you are always
in an assumed transaction between commits, and you're telling us you'd
be with raw DBI.
-
=head1 AUTHORS
Matt S. Trout <mst@shadowcatsystems.co.uk>
projects / dbsrgits/DBIx-Class.git / blobdiff