__PACKAGE__->sql_maker_class('DBIx::Class::SQLAHacks::MSSQL');
+sub _set_identity_insert {
+ my ($self, $table) = @_;
+
+ my $sql = sprintf (
+ 'SET IDENTITY_INSERT %s ON',
+ $self->sql_maker->_quote ($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) = @_;
- my $identity_insert = 0;
-
- COLUMNS:
- foreach my $col (@{$cols}) {
- if ($source->column_info($col)->{is_auto_increment}) {
- $identity_insert = 1;
- last COLUMNS;
- }
- }
+ my $is_identity_insert = (List::Util::first
+ { $source->column_info ($_)->{is_auto_increment} }
+ (@{$cols})
+ )
+ ? 1
+ : 0;
- if ($identity_insert) {
- my $table = $source->from;
- $self->dbh->do("SET IDENTITY_INSERT $table ON");
+ if ($is_identity_insert) {
+ $self->_set_identity_insert ($source->name);
}
$self->next::method(@_);
- if ($identity_insert) {
- my $table = $source->from;
- $self->dbh->do("SET IDENTITY_INSERT $table OFF");
+ if ($is_identity_insert) {
+ $self->_unset_identity_insert ($source->name);
}
}
my $self = shift;
my ($source, $to_insert) = @_;
- my $updated_cols = {};
+ my $supplied_col_info = $self->_resolve_column_info($source, [keys %$to_insert] );
my %guid_cols;
my @pk_cols = $source->primary_columns;
@pk_cols{@pk_cols} = ();
my @pk_guids = grep {
+ $source->column_info($_)->{data_type}
+ &&
$source->column_info($_)->{data_type} =~ /^uniqueidentifier/i
} @pk_cols;
my @auto_guids = grep {
+ $source->column_info($_)->{data_type}
+ &&
$source->column_info($_)->{data_type} =~ /^uniqueidentifier/i
&&
$source->column_info($_)->{auto_nextval}
my @get_guids_for =
grep { not exists $to_insert->{$_} } (@pk_guids, @auto_guids);
+ my $updated_cols = {};
+
for my $guid_col (@get_guids_for) {
- my ($new_guid) = $self->dbh->selectrow_array('SELECT NEWID()');
+ my ($new_guid) = $self->_get_dbh->selectrow_array('SELECT NEWID()');
$updated_cols->{$guid_col} = $to_insert->{$guid_col} = $new_guid;
}
+ 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 $updated_cols;
}
# cast MONEY values properly
if ($op eq 'insert' || $op eq 'update') {
my $fields = $args->[0];
- my $col_info = $self->_resolve_column_info($ident, [keys %$fields]);
for my $col (keys %$fields) {
- if ($col_info->{$col}{data_type} =~ /^money\z/i) {
+ # $ident is a result source object with INSERT/UPDATE ops
+ if ($ident->column_info ($col)->{data_type}
+ &&
+ $ident->column_info ($col)->{data_type} =~ /^money\z/i) {
my $val = $fields->{$col};
$fields->{$col} = \['CAST(? AS MONEY)', [ $col => $val ]];
}
if ($op eq 'insert') {
$sql .= ';SELECT SCOPE_IDENTITY()';
- my $col_info = $self->_resolve_column_info($ident, [map $_->[0], @{$bind}]);
- if (List::Util::first { $_->{is_auto_increment} } (values %$col_info) ) {
-
- my $table = $ident->from;
- my $identity_insert_on = "SET IDENTITY_INSERT $table ON";
- my $identity_insert_off = "SET IDENTITY_INSERT $table OFF";
- $sql = "$identity_insert_on; $sql; $identity_insert_off";
- }
}
return ($sql, $bind);
my ($op) = @_;
my ($rv, $sth, @bind) = $self->dbh_do($self->can('_dbh_execute'), @_);
+
if ($op eq 'insert') {
- $self->_identity($self->_fetch_identity($sth));
+
+ # this should bring back the result of SELECT SCOPE_IDENTITY() we tacked
+ # on in _prep_for_execute above
+ my ($identity) = eval { $sth->fetchrow_array };
+
+ # SCOPE_IDENTITY failed, but we can do something else
+ if ( (! $identity) && $self->_identity_method) {
+ ($identity) = $self->_dbh->selectrow_array(
+ 'select ' . $self->_identity_method
+ );
+ }
+
+ $self->_identity($identity);
+ $sth->finish;
}
return wantarray ? ($rv, $sth, @bind) : $rv;
}
-sub _fetch_identity {
- my ($self, $sth) = @_;
- my ($identity) = $sth->fetchrow_array;
- $sth->finish;
+sub last_insert_id { shift->_identity }
+
+#
+# MSSQL is retarded wrt ordered subselects. One needs to add a TOP
+# to *all* subqueries, but one also can't use TOP 100 PERCENT
+# http://sqladvice.com/forums/permalink/18496/22931/ShowThread.aspx#22931
+#
+sub _select_args_to_query {
+ my $self = shift;
- if ((not defined $identity) && $self->_identity_method) {
- ($identity) = $self->_dbh->selectrow_array(
- 'select ' . $self->_identity_method
- );
+ my ($sql, $prep_bind, @rest) = $self->next::method (@_);
+
+ # see if this is an ordered subquery
+ my $attrs = $_[3];
+ if ( scalar $self->_parse_order_by ($attrs->{order_by}) ) {
+ $self->throw_exception(
+ 'An ordered subselect encountered - this is not safe! Please see "Ordered Subselects" in DBIx::Class::Storage::DBI::MSSQL
+ ') unless $attrs->{unsafe_subselect_ok};
+ my $max = 2 ** 32;
+ $sql =~ s/^ \s* SELECT \s/SELECT TOP $max /xi;
}
- return $identity;
+ return wantarray
+ ? ($sql, $prep_bind, @rest)
+ : \[ "($sql)", @$prep_bind ]
+ ;
}
-sub last_insert_id { shift->_identity }
# savepoint syntax is the same as in Sybase ASE
sub _svp_begin {
my ($self, $name) = @_;
- $self->dbh->do("SAVE TRANSACTION $name");
+ $self->_get_dbh->do("SAVE TRANSACTION $name");
}
# A new SAVE TRANSACTION with the same name releases the previous one.
sub _svp_rollback {
my ($self, $name) = @_;
- $self->dbh->do("ROLLBACK TRANSACTION $name");
+ $self->_get_dbh->do("ROLLBACK TRANSACTION $name");
}
sub build_datetime_parser {
sub sqlt_type { 'SQLServer' }
-sub _sql_maker_opts {
- my ( $self, $opts ) = @_;
+sub _get_mssql_version {
+ my $self = shift;
- if ( $opts ) {
- $self->{_sql_maker_opts} = { %$opts };
+ my $data = $self->_get_dbh->selectrow_hashref('xp_msver ProductVersion');
+
+ if ($data->{Character_Value} =~ /^(\d+)\./) {
+ return $1;
+ } else {
+ $self->throw_exception(q{Your ProductVersion's Character_Value is missing or malformed!});
}
+}
+
+sub sql_maker {
+ my $self = shift;
+
+ unless ($self->_sql_maker) {
+ unless ($self->{_sql_maker_opts}{limit_dialect}) {
+ my $version = eval { $self->_get_mssql_version; } || 0;
- return { limit_dialect => 'Top', %{$self->{_sql_maker_opts}||{}} };
+ $self->{_sql_maker_opts} = {
+ limit_dialect => ($version >= 9 ? 'RowNumberOver' : 'Top'),
+ %{$self->{_sql_maker_opts}||{}}
+ };
+ }
+
+ my $maker = $self->next::method (@_);
+ }
+
+ return $self->_sql_maker;
}
1;
=head1 IMPLEMENTATION NOTES
+=head2 IDENTITY information
+
Microsoft SQL Server supports three methods of retrieving the IDENTITY
value for inserted row: IDENT_CURRENT, @@IDENTITY, and SCOPE_IDENTITY().
SCOPE_IDENTITY is used here because it is the safest. However, it must
inserts into another table with an identity will give erroneous results on
recent versions of SQL Server.
+=head2 identity insert
+
+Be aware that we have tried to make things as simple as possible for our users.
+For MSSQL that means that when a user tries to create a row, while supplying an
+explicit value for an autoincrementing column, we will try to issue the
+appropriate database call to make this possible, namely C<SET IDENTITY_INSERT
+$table_name ON>. Unfortunately this operation in MSSQL requires the
+C<db_ddladmin> privilege, which is normally not included in the standard
+write-permissions.
+
+=head2 Ordered Subselects
+
+If you attempted the following query (among many others) in Microsoft SQL
+Server
+
+ $rs->search ({}, {
+ prefetch => 'relation',
+ rows => 2,
+ offset => 3,
+ });
+
+You may be surprised to receive an exception. The reason for this is a quirk
+in the MSSQL engine itself, and sadly doesn't have a sensible workaround due
+to the way DBIC is built. DBIC can do truly wonderful things with the aid of
+subselects, and does so automatically when necessary. The list of situations
+when a subselect is necessary is long and still changes often, so it can not
+be exhaustively enumerated here. The general rule of thumb is a joined
+L<has_many|DBIx::Class::Relationship/has_many> relationship with limit/group
+applied to the left part of the join.
+
+In its "pursuit of standards" Microsft SQL Server goes to great lengths to
+forbid the use of ordered subselects. This breaks a very useful group of
+searches like "Give me things number 4 to 6 (ordered by name), and prefetch
+all their relations, no matter how many". While there is a hack which fools
+the syntax checker, the optimizer may B<still elect to break the subselect>.
+Testing has determined that while such breakage does occur (the test suite
+contains an explicit test which demonstrates the problem), it is relative
+rare. The benefits of ordered subselects are on the other hand too great to be
+outright disabled for MSSQL.
+
+Thus compromise between usability and perfection is the MSSQL-specific
+L<resultset attribute|DBIx::Class::ResultSet/ATTRIBUTES> C<unsafe_subselect_ok>.
+It is deliberately not possible to set this on the Storage level, as the user
+should inspect (and preferably regression-test) the return of every such
+ResultSet individually. The example above would work if written like:
+
+ $rs->search ({}, {
+ unsafe_subselect_ok => 1,
+ prefetch => 'relation',
+ rows => 2,
+ offset => 3,
+ });
+
+If it is possible to rewrite the search() in a way that will avoid the need
+for this flag - you are urged to do so. If DBIC internals insist that an
+ordered subselect is necessary for an operation, and you believe there is a
+different/better way to get the same result - please file a bugreport.
+
=head1 AUTHOR
See L<DBIx::Class/CONTRIBUTORS>.
projects / dbsrgits/DBIx-Class.git / blobdiff