X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FDBI%2FPg.pm;h=1444cfef1a3b0fe0857dd1be50440ff838932422;hb=734868da8acee7ff14dff8b91ab18f0edc3c10df;hp=0818aa7e5215002d79b063e2b8084680397150db;hpb=c01a6b7580315b49d0a5ab30e2693303bba9cd31;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Storage/DBI/Pg.pm b/lib/DBIx/Class/Storage/DBI/Pg.pm
index 0818aa7..1444cfe 100644
--- a/lib/DBIx/Class/Storage/DBI/Pg.pm
+++ b/lib/DBIx/Class/Storage/DBI/Pg.pm
@@ -3,146 +3,158 @@ 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 ();
 
 # 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 can_insert_returning {
+  # FIXME !!!
+  # pg before 8.2 doesn't support this, need to check version
+  return 1;
+}
+
 sub with_deferred_fk_checks {
   my ($self, $sub) = @_;
 
-  $self->_get_dbh->do('SET CONSTRAINTS ALL DEFERRED');
-  $sub->();
-}
-
-sub last_insert_id {
-  my ($self,$source,$col) = @_;
-  my $seq = ($source->column_info($col)->{sequence} ||= $self->get_autoinc_seq($source,$col))
-      or $self->throw_exception( "could not determine sequence for "
-                                 . $source->name
-                                 . ".$col, please consider adding a "
-                                 . "schema-qualified sequence to its column info"
-                               );
-
-  $self->_dbh_last_insert_id ($self->_dbh, $seq);
-}
+  my $txn_scope_guard = $self->txn_scope_guard;
 
-# there seems to be absolutely no reason to have this as a separate method,
-# but leaving intact in case someone is already overriding it
-sub _dbh_last_insert_id {
-  my ($self, $dbh, $seq) = @_;
-  $dbh->last_insert_id(undef, undef, undef, undef, {sequence => $seq});
-}
+  $self->_do_query('SET CONSTRAINTS ALL DEFERRED');
 
+  my $sg = Scope::Guard->new(sub {
+    $self->_do_query('SET CONSTRAINTS ALL IMMEDIATE');
+  });
 
-sub _get_pg_search_path {
-    my ($self,$dbh) = @_;
-    # cache the search path as ['schema','schema',...] in the storage
-    # obj
-    $self->{_pg_search_path} ||= do {
-        my @search_path;
-        my ($sp_string) = $dbh->selectrow_array('SHOW search_path');
-        while( $sp_string =~ s/("[^"]+"|[^,]+),?// ) {
-            unless( defined $1 and length $1 ) {
-                $self->throw_exception("search path sanity check failed: '$1'")
-            }
-            push @search_path, $1;
-        }
-        \@search_path
-    };
+  return Context::Preserve::preserve_context(sub { $sub->() },
+    after => sub { $txn_scope_guard->commit });
 }
 
-sub _dbh_get_autoinc_seq {
-  my ($self, $dbh, $schema, $table, $col) = @_;
-
-  # 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 {
-      @search_path = @{ $self->_get_pg_search_path($dbh) };
-  }
+sub last_insert_id {
+  my ($self,$source,@cols) = @_;
 
-  # find the sequence(s) of the column in question (should have nextval declared on it)
-  my @sequence_names;
-  foreach my $search_schema (@search_path) {
-    my $info = $dbh->column_info(undef,$search_schema,$table,$col)->fetchrow_hashref;
-    if($info && defined $info->{COLUMN_DEF}
-             && $info->{COLUMN_DEF} =~ /^nextval\(+'([^']+)'::(?:text|regclass)\)/i
-    ) {
-        push @sequence_names, $1;
-    }
-  }
+  my @values;
+
+  for my $col (@cols) {
+    my $seq = ( $source->column_info($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,
+      ));
 
-  if (@sequence_names != 1) {
-    $self->throw_exception (sprintf
-      q|Unable to reliably determine autoinc sequence name for '%s'.'%s' (possible candidates: %s)|,
-      $table,
-      $col,
-      join (', ', (@sequence_names ? @sequence_names : 'none found') ),
-    );
+    push @values, $self->_dbh->last_insert_id(undef, undef, undef, undef, {sequence => $seq});
   }
 
-  my $seq = $sequence_names[0];
+  return @values;
+}
 
-  if( $seq !~ /\./ ) {
-    my $sth = $dbh->prepare (
-      'SELECT * FROM "information_schema"."sequences" WHERE "sequence_name" = ?'
-    );
-    $sth->execute ($seq);
+sub _sequence_fetch {
+  my ($self, $function, $sequence) = @_;
 
-    my @seen_in_schemas;
-    while (my $h = $sth->fetchrow_hashref) {
-      push @seen_in_schemas, $h->{sequence_schema};
-    }
+  $self->throw_exception('No sequence to fetch') unless $sequence;
 
-    if (not @seen_in_schemas) {
-      $self->throw_exception (sprintf
-        q|Automatically determined autoinc sequence name '%s' for '%s'.'%s' does not seem to exist...'|,
-        $seq,
-        $table,
-        $col,
-      );
-    }
-    elsif (@seen_in_schemas > 1) {
-      $self->throw_exception (sprintf
-        q|Unable to reliably fully-qualify automatically determined autoinc sequence name '%s' for '%s'.'%s' (same name exist in schemas: %s)|,
-        $seq,
-        $table,
-        $col,
-        join (', ', (@seen_in_schemas)),
-      );
-    }
-    else {
-      my $sql_maker = $self->sql_maker;
-      $seq = join ('.', map { $sql_maker->_quote ($_) } ($seen_in_schemas[0], $seq) );
-    }
-  }
+  my ($val) = $self->_get_dbh->selectrow_array(
+    sprintf ("select %s('%s')", $function, $sequence)
+  );
 
-  return $seq;
+  return $val;
 }
 
-sub get_autoinc_seq {
-  my ($self,$source,$col) = @_;
+sub _dbh_get_autoinc_seq {
+  my ($self, $dbh, $source, $col) = @_;
 
   my $schema;
   my $table = $source->name;
 
-  if (ref $table eq 'SCALAR') {
-    $table = $$table;
+  # deref table name if it needs it
+  $table = $$table
+      if ref $table eq 'SCALAR';
+
+  # parse out schema name if present
+  if( $table =~ /^(.+)\.(.+)$/ ) {
+    ( $schema, $table ) = ( $1, $2 );
   }
-  elsif ($table =~ /^(.+)\.(.+)$/) {
-    ($schema, $table) = ($1, $2);
+
+  # 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,
+    ));
   }
 
-  $self->dbh_do('_dbh_get_autoinc_seq', $schema, $table, $col);
+  return $1;
 }
 
+# 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';
 }
@@ -165,12 +177,6 @@ sub bind_attribute_by_data_type {
   }
 }
 
-sub _sequence_fetch {
-  my ( $self, $type, $seq ) = @_;
-  my ($id) = $self->_get_dbh->selectrow_array("SELECT nextval('${seq}')");
-  return $id;
-}
-
 sub _svp_begin {
     my ($self, $name) = @_;
 
@@ -191,14 +197,16 @@ sub _svp_rollback {
 
 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');
 
@@ -208,13 +216,17 @@ This class implements autoincrements for PostgreSQL.
 
 =head1 POSTGRESQL SCHEMA SUPPORT
 
-This supports multiple PostgreSQL schemas, with one caveat: for
-performance reasons, the schema search path is queried the first time it is
-needed and CACHED for subsequent uses.
+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.
 
-For this reason, you should do any necessary manipulation of the
-PostgreSQL search path BEFORE instantiating your schema object, or as
-part of the on_connect_do option to connect(), for example:
+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,