package # Hide from PAUSE
DBIx::Class::SQLAHacks;
+# This module is a subclass of SQL::Abstract::Limit and includes a number
+# of DBIC-specific workarounds, not yet suitable for inclusion into the
+# SQLA core
+
use base qw/SQL::Abstract::Limit/;
use strict;
use warnings;
-use Carp::Clan qw/^DBIx::Class/;
+use Carp::Clan qw/^DBIx::Class|^SQL::Abstract/;
+use Sub::Name();
+
+BEGIN {
+ # reinstall the carp()/croak() functions imported into SQL::Abstract
+ # as Carp and Carp::Clan do not like each other much
+ no warnings qw/redefine/;
+ no strict qw/refs/;
+ for my $f (qw/carp croak/) {
+
+ my $orig = \&{"SQL::Abstract::$f"};
+ *{"SQL::Abstract::$f"} = Sub::Name::subname "SQL::Abstract::$f" =>
+ sub {
+ if (Carp::longmess() =~ /DBIx::Class::SQLAHacks::[\w]+ .+? called \s at/x) {
+ __PACKAGE__->can($f)->(@_);
+ }
+ else {
+ goto $orig;
+ }
+ };
+ }
+}
+
+# Tries to determine limit dialect.
+#
sub new {
my $self = shift->SUPER::new(@_);
}
-# Some databases (sqlite) do not handle multiple parenthesis
-# around in/between arguments. A tentative x IN ( ( 1, 2 ,3) )
-# is interpreted as x IN 1 or something similar.
-#
-# Since we currently do not have access to the SQLA AST, resort
-# to barbaric mutilation of any SQL supplied in literal form
+# ANSI standard Limit/Offset implementation. DB2 and MSSQL use this
+sub _RowNumberOver {
+ my ($self, $sql, $order, $rows, $offset ) = @_;
-sub _strip_outer_paren {
- my ($self, $arg) = @_;
+ # get the select to make the final amount of columns equal the original one
+ my ($select) = $sql =~ /^ \s* SELECT \s+ (.+?) \s+ FROM/ix
+ or croak "Unrecognizable SELECT: $sql";
- return $self->_SWITCH_refkind ($arg, {
- ARRAYREFREF => sub {
- $$arg->[0] = __strip_outer_paren ($$arg->[0]);
- return $arg;
- },
- SCALARREF => sub {
- return \__strip_outer_paren( $$arg );
- },
- FALLBACK => sub {
- return $arg
- },
- });
-}
+ # get the order_by only (or make up an order if none exists)
+ my $order_by = $self->_order_by(
+ (delete $order->{order_by}) || $self->_rno_default_order
+ );
-sub __strip_outer_paren {
- my $sql = shift;
+ # whatever is left of the order_by
+ my $group_having = $self->_order_by($order);
- if ($sql and not ref $sql) {
- while ($sql =~ /^ \s* \( (.*) \) \s* $/x ) {
- $sql = $1;
- }
- }
+ my $qalias = $self->_quote ($self->{_dbic_rs_attrs}{alias});
+
+ $sql = sprintf (<<EOS, $offset + 1, $offset + $rows, );
+
+SELECT $select FROM (
+ SELECT $qalias.*, ROW_NUMBER() OVER($order_by ) AS rno__row__index FROM (
+ ${sql}${group_having}
+ ) $qalias
+) $qalias WHERE rno__row__index BETWEEN %d AND %d
+
+EOS
+ $sql =~ s/\s*\n\s*/ /g; # easier to read in the debugger
return $sql;
}
-sub _where_field_IN {
- my ($self, $lhs, $op, $rhs) = @_;
- $rhs = $self->_strip_outer_paren ($rhs);
- return $self->SUPER::_where_field_IN ($lhs, $op, $rhs);
+# some databases are happy with OVER (), some need OVER (ORDER BY (SELECT (1)) )
+sub _rno_default_order {
+ return undef;
}
-sub _where_field_BETWEEN {
- my ($self, $lhs, $op, $rhs) = @_;
- $rhs = $self->_strip_outer_paren ($rhs);
- return $self->SUPER::_where_field_BETWEEN ($lhs, $op, $rhs);
+# Informix specific limit, almost like LIMIT/OFFSET
+sub _SkipFirst {
+ my ($self, $sql, $order, $rows, $offset) = @_;
+
+ $sql =~ s/^ \s* SELECT \s+ //ix
+ or croak "Unrecognizable SELECT: $sql";
+
+ return sprintf ('SELECT %s%s%s%s',
+ $offset
+ ? sprintf ('SKIP %d ', $offset)
+ : ''
+ ,
+ sprintf ('FIRST %d ', $rows),
+ $sql,
+ $self->_order_by ($order),
+ );
}
+# Firebird specific limit, reverse of _SkipFirst for Informix
+sub _FirstSkip {
+ my ($self, $sql, $order, $rows, $offset) = @_;
+
+ $sql =~ s/^ \s* SELECT \s+ //ix
+ or croak "Unrecognizable SELECT: $sql";
+
+ return sprintf ('SELECT %s%s%s%s',
+ sprintf ('FIRST %d ', $rows),
+ $offset
+ ? sprintf ('SKIP %d ', $offset)
+ : ''
+ ,
+ $sql,
+ $self->_order_by ($order),
+ );
+}
+# Crappy Top based Limit/Offset support. Legacy from MSSQL.
+sub _Top {
+ my ( $self, $sql, $order, $rows, $offset ) = @_;
+
+ # mangle the input sql so it can be properly aliased in the outer queries
+ $sql =~ s/^ \s* SELECT \s+ (.+?) \s+ (?=FROM)//ix
+ or croak "Unrecognizable SELECT: $sql";
+ my $sql_select = $1;
+ my @sql_select = split (/\s*,\s*/, $sql_select);
+
+ # we can't support subqueries (in fact MSSQL can't) - croak
+ if (@sql_select != @{$self->{_dbic_rs_attrs}{select}}) {
+ croak (sprintf (
+ 'SQL SELECT did not parse cleanly - retrieved %d comma separated elements, while '
+ . 'the resultset select attribure contains %d elements: %s',
+ scalar @sql_select,
+ scalar @{$self->{_dbic_rs_attrs}{select}},
+ $sql_select,
+ ));
+ }
-# DB2 is the only remaining DB using this. Even though we are not sure if
-# RowNumberOver is still needed here (should be part of SQLA) leave the
-# code in place
-sub _RowNumberOver {
- my ($self, $sql, $order, $rows, $offset ) = @_;
+ my $name_sep = $self->name_sep || '.';
+ my $esc_name_sep = "\Q$name_sep\E";
+ my $col_re = qr/ ^ (?: (.+) $esc_name_sep )? ([^$esc_name_sep]+) $ /x;
+
+ my $rs_alias = $self->{_dbic_rs_attrs}{alias};
+ my $quoted_rs_alias = $self->_quote ($rs_alias);
+
+ # construct the new select lists, rename(alias) some columns if necessary
+ my (@outer_select, @inner_select, %seen_names, %col_aliases, %outer_col_aliases);
+
+ for (@{$self->{_dbic_rs_attrs}{select}}) {
+ next if ref $_;
+ my ($table, $orig_colname) = ( $_ =~ $col_re );
+ next unless $table;
+ $seen_names{$orig_colname}++;
+ }
+
+ for my $i (0 .. $#sql_select) {
+
+ my $colsel_arg = $self->{_dbic_rs_attrs}{select}[$i];
+ my $colsel_sql = $sql_select[$i];
+
+ # this may or may not work (in case of a scalarref or something)
+ my ($table, $orig_colname) = ( $colsel_arg =~ $col_re );
+
+ my $quoted_alias;
+ # do not attempt to understand non-scalar selects - alias numerically
+ if (ref $colsel_arg) {
+ $quoted_alias = $self->_quote ('column_' . (@inner_select + 1) );
+ }
+ # column name seen more than once - alias it
+ elsif ($orig_colname &&
+ ($seen_names{$orig_colname} && $seen_names{$orig_colname} > 1) ) {
+ $quoted_alias = $self->_quote ("${table}__${orig_colname}");
+ }
+
+ # we did rename - make a record and adjust
+ if ($quoted_alias) {
+ # alias inner
+ push @inner_select, "$colsel_sql AS $quoted_alias";
+
+ # push alias to outer
+ push @outer_select, $quoted_alias;
+
+ # Any aliasing accumulated here will be considered
+ # both for inner and outer adjustments of ORDER BY
+ $self->__record_alias (
+ \%col_aliases,
+ $quoted_alias,
+ $colsel_arg,
+ $table ? $orig_colname : undef,
+ );
+ }
+
+ # otherwise just leave things intact inside, and use the abbreviated one outside
+ # (as we do not have table names anymore)
+ else {
+ push @inner_select, $colsel_sql;
+
+ my $outer_quoted = $self->_quote ($orig_colname); # it was not a duplicate so should just work
+ push @outer_select, $outer_quoted;
+ $self->__record_alias (
+ \%outer_col_aliases,
+ $outer_quoted,
+ $colsel_arg,
+ $table ? $orig_colname : undef,
+ );
+ }
+ }
+
+ my $outer_select = join (', ', @outer_select );
+ my $inner_select = join (', ', @inner_select );
+
+ %outer_col_aliases = (%outer_col_aliases, %col_aliases);
+
+ # deal with order
+ croak '$order supplied to SQLAHacks limit emulators must be a hash'
+ if (ref $order ne 'HASH');
+
+ $order = { %$order }; #copy
+
+ my $req_order = $order->{order_by};
+
+ # examine normalized version, collapses nesting
+ my $limit_order;
+ if (scalar $self->_order_by_chunks ($req_order)) {
+ $limit_order = $req_order;
+ }
+ else {
+ $limit_order = [ map
+ { join ('', $rs_alias, $name_sep, $_ ) }
+ ( $self->{_dbic_rs_attrs}{_source_handle}->resolve->primary_columns )
+ ];
+ }
+
+ my ( $order_by_inner, $order_by_outer ) = $self->_order_directions($limit_order);
+ my $order_by_requested = $self->_order_by ($req_order);
+
+ # generate the rest
+ delete $order->{order_by};
+ my $grpby_having = $self->_order_by ($order);
+
+ # short circuit for counts - the ordering complexity is needless
+ if ($self->{_dbic_rs_attrs}{-for_count_only}) {
+ return "SELECT TOP $rows $inner_select $sql $grpby_having $order_by_outer";
+ }
+
+ # we can't really adjust the order_by columns, as introspection is lacking
+ # resort to simple substitution
+ for my $col (keys %outer_col_aliases) {
+ for ($order_by_requested, $order_by_outer) {
+ $_ =~ s/\s+$col\s+/ $outer_col_aliases{$col} /g;
+ }
+ }
+ for my $col (keys %col_aliases) {
+ $order_by_inner =~ s/\s+$col\s+/ $col_aliases{$col} /g;
+ }
- $offset += 1;
- my $last = $rows + $offset - 1;
- my ( $order_by ) = $self->_order_by( $order );
- $sql = <<"SQL";
-SELECT * FROM
-(
- SELECT Q1.*, ROW_NUMBER() OVER( ) AS ROW_NUM FROM (
+ my $inner_lim = $rows + $offset;
+
+ $sql = "SELECT TOP $inner_lim $inner_select $sql $grpby_having $order_by_inner";
+
+ if ($offset) {
+ $sql = <<"SQL";
+
+ SELECT TOP $rows $outer_select FROM
+ (
$sql
- $order_by
- ) Q1
-) Q2
-WHERE ROW_NUM BETWEEN $offset AND $last
+ ) $quoted_rs_alias
+ $order_by_outer
+SQL
+ }
+
+ if ($order_by_requested) {
+ $sql = <<"SQL";
+
+ SELECT $outer_select FROM
+ ( $sql ) $quoted_rs_alias
+ $order_by_requested
SQL
+ }
+
+ $sql =~ s/\s*\n\s*/ /g; # parsing out multiline statements is harder than a single line
return $sql;
}
+# action at a distance to shorten Top code above
+sub __record_alias {
+ my ($self, $register, $alias, $fqcol, $col) = @_;
+
+ # record qualified name
+ $register->{$fqcol} = $alias;
+ $register->{$self->_quote($fqcol)} = $alias;
+
+ return unless $col;
+
+ # record unqualified name, undef (no adjustment) if a duplicate is found
+ if (exists $register->{$col}) {
+ $register->{$col} = undef;
+ }
+ else {
+ $register->{$col} = $alias;
+ }
+
+ $register->{$self->_quote($col)} = $register->{$col};
+}
+
+
# While we're at it, this should make LIMIT queries more efficient,
# without digging into things too deeply
return $self->{_cached_syntax} ||= $self->SUPER::_find_syntax($syntax);
}
+my $for_syntax = {
+ update => 'FOR UPDATE',
+ shared => 'FOR SHARE',
+};
+# Quotes table names, handles "limit" dialects (e.g. where rownum between x and
+# y), supports SELECT ... FOR UPDATE and SELECT ... FOR SHARE.
sub select {
my ($self, $table, $fields, $where, $order, @rest) = @_;
- local $self->{having_bind} = [];
- local $self->{from_bind} = [];
- if (ref $table eq 'SCALAR') {
- $table = $$table;
- }
- elsif (not ref $table) {
+ $self->{"${_}_bind"} = [] for (qw/having from order/);
+
+ if (not ref($table) or ref($table) eq 'SCALAR') {
$table = $self->_quote($table);
}
+
local $self->{rownum_hack_count} = 1
if (defined $rest[0] && $self->{limit_dialect} eq 'RowNum');
@rest = (-1) unless defined $rest[0];
my ($sql, @where_bind) = $self->SUPER::select(
$table, $self->_recurse_fields($fields), $where, $order, @rest
);
- $sql .=
- $self->{for} ?
- (
- $self->{for} eq 'update' ? ' FOR UPDATE' :
- $self->{for} eq 'shared' ? ' FOR SHARE' :
- ''
- ) :
- ''
- ;
- return wantarray ? ($sql, @{$self->{from_bind}}, @where_bind, @{$self->{having_bind}}) : $sql;
+ if (my $for = delete $self->{_dbic_rs_attrs}{for}) {
+ $sql .= " $for_syntax->{$for}" if $for_syntax->{$for};
+ }
+
+ return wantarray ? ($sql, @{$self->{from_bind}}, @where_bind, @{$self->{having_bind}}, @{$self->{order_bind}} ) : $sql;
}
+# Quotes table names, and handles default inserts
sub insert {
my $self = shift;
my $table = shift;
- $table = $self->_quote($table) unless ref($table);
+ $table = $self->_quote($table);
+
+ # SQLA will emit INSERT INTO $table ( ) VALUES ( )
+ # which is sadly understood only by MySQL. Change default behavior here,
+ # until SQLA2 comes with proper dialect support
+ if (! $_[0] or (ref $_[0] eq 'HASH' and !keys %{$_[0]} ) ) {
+ return "INSERT INTO ${table} DEFAULT VALUES"
+ }
+
$self->SUPER::insert($table, @_);
}
+# Just quotes table names.
sub update {
my $self = shift;
my $table = shift;
- $table = $self->_quote($table) unless ref($table);
+ $table = $self->_quote($table);
$self->SUPER::update($table, @_);
}
+# Just quotes table names.
sub delete {
my $self = shift;
my $table = shift;
- $table = $self->_quote($table) unless ref($table);
+ $table = $self->_quote($table);
$self->SUPER::delete($table, @_);
}
? ' AS col'.$self->{rownum_hack_count}++
: '')
} @$fields);
- } elsif ($ref eq 'HASH') {
- foreach my $func (keys %$fields) {
- if ($func eq 'distinct') {
- my $_fields = $fields->{$func};
- if (ref $_fields eq 'ARRAY' && @{$_fields} > 1) {
- croak (
- 'The select => { distinct => ... } syntax is not supported for multiple columns.'
- .' Instead please use { group_by => [ qw/' . (join ' ', @$_fields) . '/ ] }'
- .' or { select => [ qw/' . (join ' ', @$_fields) . '/ ], distinct => 1 }'
- );
- }
- else {
- $_fields = @{$_fields}[0] if ref $_fields eq 'ARRAY';
- carp (
- 'The select => { distinct => ... } syntax will be deprecated in DBIC version 0.09,'
- ." please use { group_by => '${_fields}' } or { select => '${_fields}', distinct => 1 }"
- );
- }
- }
- return $self->_sqlcase($func)
- .'( '.$self->_recurse_fields($fields->{$func}).' )';
+ }
+ elsif ($ref eq 'HASH') {
+ my %hash = %$fields;
+
+ my $as = delete $hash{-as}; # if supplied
+
+ my ($func, $args) = each %hash;
+ delete $hash{$func};
+
+ if (lc ($func) eq 'distinct' && ref $args eq 'ARRAY' && @$args > 1) {
+ croak (
+ 'The select => { distinct => ... } syntax is not supported for multiple columns.'
+ .' Instead please use { group_by => [ qw/' . (join ' ', @$args) . '/ ] }'
+ .' or { select => [ qw/' . (join ' ', @$args) . '/ ], distinct => 1 }'
+ );
+ }
+
+ my $select = sprintf ('%s( %s )%s',
+ $self->_sqlcase($func),
+ $self->_recurse_fields($args),
+ $as
+ ? sprintf (' %s %s', $self->_sqlcase('as'), $self->_quote ($as) )
+ : ''
+ );
+
+ # there should be nothing left
+ if (keys %hash) {
+ croak "Malformed select argument - too many keys in hash: " . join (',', keys %$fields );
}
+
+ return $select;
}
# Is the second check absolutely necessary?
elsif ( $ref eq 'REF' and ref($$fields) eq 'ARRAY' ) {
}
sub _order_by {
- my $self = shift;
- my $ret = '';
- my @extra;
- if (ref $_[0] eq 'HASH') {
- if (defined $_[0]->{group_by}) {
- $ret = $self->_sqlcase(' group by ')
- .$self->_recurse_fields($_[0]->{group_by}, { no_rownum_hack => 1 });
+ my ($self, $arg) = @_;
+
+ if (ref $arg eq 'HASH' and keys %$arg and not grep { $_ =~ /^-(?:desc|asc)/i } keys %$arg ) {
+
+ my $ret = '';
+
+ if (my $g = $self->_recurse_fields($arg->{group_by}, { no_rownum_hack => 1 }) ) {
+ $ret = $self->_sqlcase(' group by ') . $g;
}
- if (defined $_[0]->{having}) {
- my $frag;
- ($frag, @extra) = $self->_recurse_where($_[0]->{having});
- push(@{$self->{having_bind}}, @extra);
+
+ if (defined $arg->{having}) {
+ my ($frag, @bind) = $self->_recurse_where($arg->{having});
+ push(@{$self->{having_bind}}, @bind);
$ret .= $self->_sqlcase(' having ').$frag;
}
- if (defined $_[0]->{order_by}) {
- $ret .= $self->_order_by($_[0]->{order_by});
- }
- if (grep { $_ =~ /^-(desc|asc)/i } keys %{$_[0]}) {
- return $self->SUPER::_order_by($_[0]);
- }
- } elsif (ref $_[0] eq 'SCALAR') {
- $ret = $self->_sqlcase(' order by ').${ $_[0] };
- } elsif (ref $_[0] eq 'ARRAY' && @{$_[0]}) {
- my @order = @{+shift};
- $ret = $self->_sqlcase(' order by ')
- .join(', ', map {
- my $r = $self->_order_by($_, @_);
- $r =~ s/^ ?ORDER BY //i;
- $r;
- } @order);
- } else {
- $ret = $self->SUPER::_order_by(@_);
- }
- return $ret;
-}
-sub _order_directions {
- my ($self, $order) = @_;
- return $self->SUPER::_order_directions( $self->_resolve_order($order) );
-}
-
-sub _resolve_order {
- my ($self, $order) = @_;
- $order = $order->{order_by} if (ref $order eq 'HASH' and $order->{order_by});
+ if (defined $arg->{order_by}) {
+ my ($frag, @bind) = $self->SUPER::_order_by($arg->{order_by});
+ push(@{$self->{order_bind}}, @bind);
+ $ret .= $frag;
+ }
- if (ref $order eq 'HASH') {
- $order = [$self->_resolve_order_hash($order)];
+ return $ret;
}
- elsif (ref $order eq 'ARRAY') {
- $order = [map {
- if (ref ($_) eq 'SCALAR') {
- $$_
- }
- elsif (ref ($_) eq 'HASH') {
- $self->_resolve_order_hash($_)
- }
- else {
- $_
- }
- } @$order];
+ else {
+ my ($sql, @bind) = $self->SUPER::_order_by ($arg);
+ push(@{$self->{order_bind}}, @bind);
+ return $sql;
}
-
- return $order;
}
-sub _resolve_order_hash {
+sub _order_directions {
my ($self, $order) = @_;
- my @new_order;
- foreach my $key (keys %{ $order }) {
- if ($key =~ /^-(desc|asc)/i ) {
- my $direction = $1;
- my $type = ref $order->{ $key };
- if ($type eq 'ARRAY') {
- push @new_order, map( "$_ $direction", @{ $order->{ $key } } );
- } elsif (!$type) {
- push @new_order, "$order->{$key} $direction";
- } else {
- croak "hash order_by can only contain Scalar or Array, not $type";
- }
- } else {
- croak "$key is not a valid direction, use -asc or -desc";
- }
- }
- return @new_order;
+
+ # strip bind values - none of the current _order_directions users support them
+ return $self->SUPER::_order_directions( [ map
+ { ref $_ ? $_->[0] : $_ }
+ $self->_order_by_chunks ($order)
+ ]);
}
sub _table {
foreach my $j (@join) {
my ($to, $on) = @$j;
+
# check whether a join type exists
- my $join_clause = '';
my $to_jt = ref($to) eq 'ARRAY' ? $to->[0] : $to;
- if (ref($to_jt) eq 'HASH' and exists($to_jt->{-join_type})) {
- $join_clause = ' '.uc($to_jt->{-join_type}).' JOIN ';
- } else {
- $join_clause = ' JOIN ';
+ my $join_type;
+ if (ref($to_jt) eq 'HASH' and defined($to_jt->{-join_type})) {
+ $join_type = $to_jt->{-join_type};
+ $join_type =~ s/^\s+ | \s+$//xg;
}
- push(@sqlf, $join_clause);
+
+ $join_type = $self->{_default_jointype} if not defined $join_type;
+
+ my $join_clause = sprintf ('%s JOIN ',
+ $join_type ? ' ' . uc($join_type) : ''
+ );
+ push @sqlf, $join_clause;
if (ref $to eq 'ARRAY') {
push(@sqlf, '(', $self->_recurse_from(@$to), ')');
sub _quote {
my ($self, $label) = @_;
return '' unless defined $label;
+ return $$label if ref($label) eq 'SCALAR';
return "*" if $label eq '*';
return $label unless $self->{quote_char};
if(ref $self->{quote_char} eq "ARRAY"){
return $self->{limit_dialect};
}
+# Set to an array-ref to specify separate left and right quotes for table names.
+# A single scalar is equivalen to [ $char, $char ]
sub quote_char {
my $self = shift;
$self->{quote_char} = shift if @_;
return $self->{quote_char};
}
+# Character separating quoted table names.
sub name_sep {
my $self = shift;
$self->{name_sep} = shift if @_;
}
1;
-
-__END__
-
-=pod
-
-=head1 NAME
-
-DBIx::Class::SQLAHacks - This module is a subclass of SQL::Abstract::Limit
-and includes a number of DBIC-specific workarounds, not yet suitable for
-inclusion into SQLA proper.
-
-=head1 METHODS
-
-=head2 new
-
-Tries to determine limit dialect.
-
-=head2 select
-
-Quotes table names, handles "limit" dialects (e.g. where rownum between x and
-y), supports SELECT ... FOR UPDATE and SELECT ... FOR SHARE.
-
-=head2 insert update delete
-
-Just quotes table names.
-
-=head2 limit_dialect
-
-Specifies the dialect of used for implementing an SQL "limit" clause for
-restricting the number of query results returned. Valid values are: RowNum.
-
-See L<DBIx::Class::Storage::DBI/connect_info> for details.
-
-=head2 name_sep
-
-Character separating quoted table names.
-
-See L<DBIx::Class::Storage::DBI/connect_info> for details.
-
-=head2 quote_char
-
-Set to an array-ref to specify separate left and right quotes for table names.
-
-See L<DBIx::Class::Storage::DBI/connect_info> for details.
-
-=cut
-