X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FDBI%2FPg.pm;h=d1319e944dd6e67e429fbf0ac6be6c7e5cdc02c9;hb=07cda1c5a7df6656772dfd65c488c19c15126168;hp=e925529e822f8cdbc76a8243d07181afb24797ee;hpb=7dfe289b0aa53b8a0e522545ae294d785aa9ed19;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Storage/DBI/Pg.pm b/lib/DBIx/Class/Storage/DBI/Pg.pm
index e925529..d1319e9 100644
--- a/lib/DBIx/Class/Storage/DBI/Pg.pm
+++ b/lib/DBIx/Class/Storage/DBI/Pg.pm
@@ -3,87 +3,164 @@ package DBIx::Class::Storage::DBI::Pg;
 use strict;
 use warnings;
 
-use base qw/DBIx::Class::Storage::DBI::MultiColumnIn/;
+use base qw/
+    DBIx::Class::Storage::DBI::MultiColumnIn
+/;
 use mro 'c3';
 
 use DBD::Pg qw(:pg_types);
+use Scope::Guard ();
+use Context::Preserve 'preserve_context';
+use namespace::clean;
+
+__PACKAGE__->sql_limit_dialect ('LimitOffset');
 
 # Ask for a DBD::Pg with array support
-warn "DBD::Pg 2.9.2 or greater is strongly recommended\n"
+warn __PACKAGE__.": DBD::Pg 2.9.2 or greater is strongly recommended\n"
   if ($DBD::Pg::VERSION < 2.009002);  # pg uses (used?) version::qv()
 
+sub _determine_supports_insert_returning {
+  return shift->_server_info->{normalized_dbms_version} >= 8.002
+    ? 1
+    : 0
+  ;
+}
+
 sub with_deferred_fk_checks {
   my ($self, $sub) = @_;
 
-  $self->dbh->do('SET CONSTRAINTS ALL DEFERRED');
-  $sub->();
-}
+  my $txn_scope_guard = $self->txn_scope_guard;
+
+  $self->_do_query('SET CONSTRAINTS ALL DEFERRED');
 
-sub _dbh_last_insert_id {
-  my ($self, $dbh, $seq) = @_;
-  $dbh->last_insert_id(undef, undef, undef, undef, {sequence => $seq});
+  my $sg = Scope::Guard->new(sub {
+    $self->_do_query('SET CONSTRAINTS ALL IMMEDIATE');
+  });
+
+  return preserve_context { $sub->() } after => sub { $txn_scope_guard->commit };
 }
 
+# only used when INSERT ... RETURNING is disabled
 sub last_insert_id {
-  my ($self,$source,$col) = @_;
-  my $seq = ($source->column_info($col)->{sequence} ||= $self->get_autoinc_seq($source,$col));
-  $self->throw_exception("could not fetch primary key for " . $source->name . ", could not "
-    . "get autoinc sequence for $col (check that table and column specifications are correct "
-    . "and in the correct case)") unless defined $seq;
-  $self->dbh_do('_dbh_last_insert_id', $seq);
+  my ($self,$source,@cols) = @_;
+
+  my @values;
+
+  my $col_info = $source->columns_info(\@cols);
+
+  for my $col (@cols) {
+    my $seq = ( $col_info->{$col}{sequence} ||= $self->dbh_do('_dbh_get_autoinc_seq', $source, $col) )
+      or $self->throw_exception( sprintf(
+        'could not determine sequence for column %s.%s, please consider adding a schema-qualified sequence to its column info',
+          $source->name,
+          $col,
+      ));
+
+    push @values, $self->_dbh->last_insert_id(undef, undef, undef, undef, {sequence => $seq});
+  }
+
+  return @values;
+}
+
+sub _sequence_fetch {
+  my ($self, $function, $sequence) = @_;
+
+  $self->throw_exception('No sequence to fetch') unless $sequence;
+
+  my ($val) = $self->_get_dbh->selectrow_array(
+    sprintf ("select %s('%s')", $function, (ref $sequence eq 'SCALAR') ? $$sequence : $sequence)
+  );
+
+  return $val;
 }
 
 sub _dbh_get_autoinc_seq {
-  my ($self, $dbh, $schema, $table, @pri) = @_;
-
-  # get the list of postgres schemas to search.  if we have a schema
-  # specified, use that.  otherwise, use the search path
-  my @search_path;
-  if( defined $schema and length $schema ) {
-      @search_path = ( $schema );
-  } else {
-      my ($search_path) = $dbh->selectrow_array('SHOW search_path');
-      while( $search_path =~ s/([^,]+),?// ) {
-          unless( defined $1 and length $1 ) {
-              $self->throw_exception("search path sanity check failed: '$1'")
-          }
-          push @search_path, $1;
-      }
-  }
+  my ($self, $dbh, $source, $col) = @_;
+
+  my $schema;
+  my $table = $source->name;
 
-  foreach my $search_schema (@search_path) {
-      foreach my $col (@pri) {
-          my $info = $dbh->column_info(undef,$search_schema,$table,$col)->fetchrow_hashref;
-          if($info) {
-              # if we get here, we have definitely found the right
-              # column.
-              if( defined $info->{COLUMN_DEF} and
-                  $info->{COLUMN_DEF}
-                    =~ /^nextval\(+'([^']+)'::(?:text|regclass)\)/i
-                ) {
-                  my $seq = $1;
-                  return $seq =~ /\./ ? $seq : $info->{TABLE_SCHEM} . "." . $seq;
-              } else {
-                  # we have found the column, but cannot figure out
-                  # the nextval seq
-                  return;
-              }
-          }
-      }
+  # deref table name if it needs it
+  $table = $$table
+      if ref $table eq 'SCALAR';
+
+  # parse out schema name if present
+  if( $table =~ /^(.+)\.(.+)$/ ) {
+    ( $schema, $table ) = ( $1, $2 );
   }
-  return;
-}
 
-sub get_autoinc_seq {
-  my ($self,$source,$col) = @_;
+  # get the column default using a Postgres-specific pg_catalog query
+  my $seq_expr = $self->_dbh_get_column_default( $dbh, $schema, $table, $col );
+
+  # if no default value is set on the column, or if we can't parse the
+  # default value as a sequence, throw.
+  unless ( defined $seq_expr and $seq_expr =~ /^nextval\(+'([^']+)'::(?:text|regclass)\)/i ) {
+    $seq_expr = '' unless defined $seq_expr;
+    $schema = "$schema." if defined $schema && length $schema;
+    $self->throw_exception( sprintf (
+      'no sequence found for %s%s.%s, check the RDBMS table definition or explicitly set the '.
+      "'sequence' for this column in %s",
+        $schema ? "$schema." : '',
+        $table,
+        $col,
+        $source->source_name,
+    ));
+  }
 
-  my @pri = $source->primary_columns;
-  my ($schema,$table) = $source->name =~ /^(.+)\.(.+)$/ ? ($1,$2)
-    : (undef,$source->name);
+  return $1;
+}
 
-  $self->dbh_do('_dbh_get_autoinc_seq', $schema, $table, @pri);
+# custom method for fetching column default, since column_info has a
+# bug with older versions of DBD::Pg
+sub _dbh_get_column_default {
+  my ( $self, $dbh, $schema, $table, $col ) = @_;
+
+  # Build and execute a query into the pg_catalog to find the Pg
+  # expression for the default value for this column in this table.
+  # If the table name is schema-qualified, query using that specific
+  # schema name.
+
+  # Otherwise, find the table in the standard Postgres way, using the
+  # search path.  This is done with the pg_catalog.pg_table_is_visible
+  # function, which returns true if a given table is 'visible',
+  # meaning the first table of that name to be found in the search
+  # path.
+
+  # I *think* we can be assured that this query will always find the
+  # correct column according to standard Postgres semantics.
+  #
+  # -- rbuels
+
+  my $sqlmaker = $self->sql_maker;
+  local $sqlmaker->{bindtype} = 'normal';
+
+  my ($where, @bind) = $sqlmaker->where ({
+    'a.attnum' => {'>', 0},
+    'c.relname' => $table,
+    'a.attname' => $col,
+    -not_bool => 'a.attisdropped',
+    (defined $schema && length $schema)
+      ? ( 'n.nspname' => $schema )
+      : ( -bool => \'pg_catalog.pg_table_is_visible(c.oid)' )
+  });
+
+  my ($seq_expr) = $dbh->selectrow_array(<<EOS,undef,@bind);
+
+SELECT
+  (SELECT pg_catalog.pg_get_expr(d.adbin, d.adrelid)
+   FROM pg_catalog.pg_attrdef d
+   WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef)
+FROM pg_catalog.pg_class c
+     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
+     JOIN pg_catalog.pg_attribute a ON a.attrelid = c.oid
+$where
+
+EOS
+
+  return $seq_expr;
 }
 
+
 sub sqlt_type {
   return 'PostgreSQL';
 }
@@ -106,50 +183,83 @@ sub bind_attribute_by_data_type {
   }
 }
 
-sub _sequence_fetch {
-  my ( $self, $type, $seq ) = @_;
-  my ($id) = $self->dbh->selectrow_array("SELECT nextval('${seq}')");
-  return $id;
-}
-
 sub _svp_begin {
     my ($self, $name) = @_;
 
-    $self->dbh->pg_savepoint($name);
+    $self->_get_dbh->pg_savepoint($name);
 }
 
 sub _svp_release {
     my ($self, $name) = @_;
 
-    $self->dbh->pg_release($name);
+    $self->_get_dbh->pg_release($name);
 }
 
 sub _svp_rollback {
     my ($self, $name) = @_;
 
-    $self->dbh->pg_rollback_to($name);
+    $self->_get_dbh->pg_rollback_to($name);
+}
+
+sub deployment_statements {
+  my $self = shift;;
+  my ($schema, $type, $version, $dir, $sqltargs, @rest) = @_;
+
+  $sqltargs ||= {};
+
+  if (
+    ! exists $sqltargs->{producer_args}{postgres_version}
+      and
+    my $dver = $self->_server_info->{normalized_dbms_version}
+  ) {
+    $sqltargs->{producer_args}{postgres_version} = $dver;
+  }
+
+  $self->next::method($schema, $type, $version, $dir, $sqltargs, @rest);
 }
 
 1;
 
+__END__
+
 =head1 NAME
 
 DBIx::Class::Storage::DBI::Pg - Automatic primary key class for PostgreSQL
 
 =head1 SYNOPSIS
 
-  # In your table classes
-  __PACKAGE__->load_components(qw/PK::Auto Core/);
+  # In your result (table) classes
+  use base 'DBIx::Class::Core';
   __PACKAGE__->set_primary_key('id');
-  __PACKAGE__->sequence('mysequence');
 
 =head1 DESCRIPTION
 
 This class implements autoincrements for PostgreSQL.
 
+=head1 POSTGRESQL SCHEMA SUPPORT
+
+This driver supports multiple PostgreSQL schemas, with one caveat: for
+performance reasons, data about the search path, sequence names, and
+so forth is queried as needed and CACHED for subsequent uses.
+
+For this reason, once your schema is instantiated, you should not
+change the PostgreSQL schema search path for that schema's database
+connection. If you do, Bad Things may happen.
+
+You should do any necessary manipulation of the search path BEFORE
+instantiating your schema object, or as part of the on_connect_do
+option to connect(), for example:
+
+   my $schema = My::Schema->connect
+                  ( $dsn,$user,$pass,
+                    { on_connect_do =>
+                        [ 'SET search_path TO myschema, foo, public' ],
+                    },
+                  );
+
 =head1 AUTHORS
 
-Marcus Ramberg <m.ramberg@cpan.org>
+See L<DBIx::Class/CONTRIBUTORS>
 
 =head1 LICENSE