Unify the MSSQL and DB2 RNO implementations - they are the same

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / Storage / DBI / MSSQL.pm

diff --git a/lib/DBIx/Class/Storage/DBI/MSSQL.pm b/lib/DBIx/Class/Storage/DBI/MSSQL.pm
index c4611b3..28b87f2 100644 (file)
--- a/lib/DBIx/Class/Storage/DBI/MSSQL.pm
+++ b/lib/DBIx/Class/Storage/DBI/MSSQL.pm
@@ -16,24 +16,54 @@ __PACKAGE__->sql_maker_class('DBIx::Class::SQLAHacks::MSSQL');
 
 sub _set_identity_insert {
   my ($self, $table) = @_;
-  $self->_get_dbh->do (sprintf
+
+  my $sql = sprintf (
     'SET IDENTITY_INSERT %s ON',
-    $self->sql_maker->_quote ($table)
+    $self->sql_maker->_quote ($table),
+  );
+
+  my $dbh = $self->_get_dbh;
+  eval { $dbh->do ($sql) };
+  if ($@) {
+    $self->throw_exception (sprintf "Error executing '%s': %s",
+      $sql,
+      $dbh->errstr,
+    );
+  }
+}
+
+sub _unset_identity_insert {
+  my ($self, $table) = @_;
+
+  my $sql = sprintf (
+    'SET IDENTITY_INSERT %s OFF',
+    $self->sql_maker->_quote ($table),
   );
+
+  my $dbh = $self->_get_dbh;
+  $dbh->do ($sql);
 }
 
 sub insert_bulk {
   my $self = shift;
   my ($source, $cols, $data) = @_;
 
-  if (List::Util::first
+  my $is_identity_insert = (List::Util::first
       { $source->column_info ($_)->{is_auto_increment} }
       (@{$cols})
-  ) {
-      $self->_set_identity_insert ($source->name);
+  )
+     ? 1
+     : 0;
+
+  if ($is_identity_insert) {
+     $self->_set_identity_insert ($source->name);
   }
 
   $self->next::method(@_);
+
+  if ($is_identity_insert) {
+     $self->_unset_identity_insert ($source->name);
+  }
 }
 
 # support MSSQL GUID column types
@@ -73,12 +103,21 @@ sub insert {
     $updated_cols->{$guid_col} = $to_insert->{$guid_col} = $new_guid;
   }
 
-  if (List::Util::first { $_->{is_auto_increment} } (values %$supplied_col_info) ) {
-    $self->_set_identity_insert ($source->name);
+  my $is_identity_insert = (List::Util::first { $_->{is_auto_increment} } (values %$supplied_col_info) )
+     ? 1
+     : 0;
+
+  if ($is_identity_insert) {
+     $self->_set_identity_insert ($source->name);
   }
 
   $updated_cols = { %$updated_cols, %{ $self->next::method(@_) } };
 
+  if ($is_identity_insert) {
+     $self->_unset_identity_insert ($source->name);
+  }
+
+
   return $updated_cols;
 }
 
@@ -121,7 +160,7 @@ sub _execute {
 
     # this should bring back the result of SELECT SCOPE_IDENTITY() we tacked
     # on in _prep_for_execute above
-    my ($identity) = $sth->fetchrow_array;
+    my ($identity) = eval { $sth->fetchrow_array };
 
     # SCOPE_IDENTITY failed, but we can do something else
     if ( (! $identity) && $self->_identity_method) {
@@ -139,6 +178,41 @@ sub _execute {
 
 sub last_insert_id { shift->_identity }
 
+#
+# MSSQL is retarded wrt ordered subselects. One needs to add a TOP 100%
+# to *all* subqueries, do it here.
+#
+sub _select_args_to_query {
+  my $self = shift;
+
+  # _select_args does some shady action at a distance
+  # see DBI.pm for more info
+  my $sql_maker = $self->sql_maker;
+  my ($op, $bind, $ident, $bind_attrs, $select, $cond, $order, $rows, $offset);
+  {
+    local $sql_maker->{_dbic_rs_attrs};
+    ($op, $bind, $ident, $bind_attrs, $select, $cond, $order, $rows, $offset) = $self->_select_args(@_);
+  }
+
+  if (
+    ($rows || $offset)
+      ||
+    not scalar $sql_maker->_order_by_chunks ($order->{order_by})
+  ) {
+    # either limited RS or no ordering, just short circuit
+    return $self->next::method (@_);
+  }
+
+  my ($sql, $prep_bind, @rest) = $self->next::method (@_);
+  $sql =~ s/^ \s* SELECT \s/SELECT TOP 100 PERCENT /xi;
+
+  return wantarray
+    ? ($sql, $prep_bind, @rest)
+    : \[ "($sql)", @$prep_bind ]
+  ;
+}
+
+
 # savepoint syntax is the same as in Sybase ASE
 
 sub _svp_begin {
@@ -173,7 +247,7 @@ sub _sql_maker_opts {
     $self->{_sql_maker_opts} = { %$opts };
   }
 
-  return { limit_dialect => 'Top', %{$self->{_sql_maker_opts}||{}} };
+  return { limit_dialect => 'RowNumberOver', %{$self->{_sql_maker_opts}||{}} };
 }
 
 1;
@@ -211,13 +285,15 @@ This is more dangerous, as inserting into a table with an on insert trigger that
 inserts into another table with an identity will give erroneous results on
 recent versions of SQL Server.
 
-=head2 bulk_insert
+=head2 identity insert
 
 Be aware that we have tried to make things as simple as possible for our users.
-For MSSQL that means that when a user tries to do a populate/bulk_insert which
-includes an autoincrementing column, we will try to tell the database to allow
-the insertion of the autoinc column.  But the user must have the db_ddladmin
-role membership, otherwise you will get a fairly opaque error message.
+For MSSQL that means that when a user tries to create a row, while supplying an
+explicit value for an autoincrementing column, we will try to issue the
+appropriate database call to make this possible, namely C<SET IDENTITY_INSERT
+$table_name ON>. Unfortunately this operation in MSSQL requires the
+C<db_ddladmin> privilege, which is normally not included in the standard
+write-permissions.
 
 =head1 AUTHOR