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;
no warnings qw/redefine/;
no strict qw/refs/;
for my $f (qw/carp croak/) {
+
my $orig = \&{"SQL::Abstract::$f"};
*{"SQL::Abstract::$f"} = sub {
local $Carp::CarpLevel = 1; # even though Carp::Clan ignores this, $orig will not
- if (Carp::longmess() =~ /DBIx::Class::SQLAHacks::[\w]+\(\) called/) {
+ if (Carp::longmess() =~ /DBIx::Class::SQLAHacks::[\w]+ .+? called \s at/x) {
__PACKAGE__->can($f)->(@_);
}
else {
}
}
+
+# Tries to determine limit dialect.
+#
sub new {
my $self = shift->SUPER::new(@_);
$self;
}
-
# Some databases (sqlite) do not handle multiple parenthesis
-# around in/between arguments. A tentative x IN ( ( 1, 2 ,3) )
+# around in/between arguments. A tentative x IN ( (1, 2 ,3) )
# is interpreted as x IN 1 or something similar.
#
# Since we currently do not have access to the SQLA AST, resort
# to barbaric mutilation of any SQL supplied in literal form
-
sub _strip_outer_paren {
my ($self, $arg) = @_;
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,
+ ));
+ }
+
+ 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 $last = $rows + $offset;
+ my $req_order = $order->{order_by};
- my $req_order = $self->_order_by ($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 $limit_order = $req_order ? $order->{order_by} : $order->{_virtual_order_by};
+ my ( $order_by_inner, $order_by_outer ) = $self->_order_directions($limit_order);
+ my $order_by_requested = $self->_order_by ($req_order);
- delete $order->{$_} for qw/order_by _virtual_order_by/;
+ # generate the rest
+ delete $order->{order_by};
my $grpby_having = $self->_order_by ($order);
- my ( $order_by_inner, $order_by_outer ) = $self->_order_directions($limit_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;
+ }
- $sql =~ s/^\s*(SELECT|select)//;
- $sql = <<"SQL";
- SELECT * FROM
- (
- SELECT TOP $rows * 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
(
- SELECT TOP $last $sql $grpby_having $order_by_inner
- ) AS foo
+ $sql
+ ) $quoted_rs_alias
$order_by_outer
- ) AS bar
- $req_order
+SQL
+ }
+
+ if ($order_by_requested) {
+ $sql = <<"SQL";
+
+ SELECT $outer_select FROM
+ ( $sql ) $quoted_rs_alias
+ $order_by_requested
SQL
- return $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};
}
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) = @_;
$self->{"${_}_bind"} = [] for (qw/having from order/);
- if (ref $table eq 'SCALAR') {
- $table = $$table;
- }
- elsif (not ref $table) {
+ if (not ref($table) or ref($table) eq 'SCALAR') {
$table = $self->_quote($table);
}
+
local $self->{rownum_hack_count} = 1
if (defined $rest[0] && $self->{limit_dialect} eq 'RowNum');
@rest = (-1) unless defined $rest[0];
my ($sql, @where_bind) = $self->SUPER::select(
$table, $self->_recurse_fields($fields), $where, $order, @rest
);
- $sql .=
- $self->{for} ?
- (
- $self->{for} eq 'update' ? ' FOR UPDATE' :
- $self->{for} eq 'shared' ? ' FOR SHARE' :
- ''
- ) :
- ''
- ;
+ if (my $for = delete $self->{_dbic_rs_attrs}{for}) {
+ $sql .= " $for_syntax->{$for}" if $for_syntax->{$for};
+ }
+
return wantarray ? ($sql, @{$self->{from_bind}}, @where_bind, @{$self->{having_bind}}, @{$self->{order_bind}} ) : $sql;
}
+# Quotes table names, and handles default inserts
sub insert {
my $self = shift;
my $table = shift;
- $table = $self->_quote($table) unless ref($table);
+ $table = $self->_quote($table);
# SQLA will emit INSERT INTO $table ( ) VALUES ( )
# which is sadly understood only by MySQL. Change default behavior here,
$self->SUPER::insert($table, @_);
}
+# Just quotes table names.
sub update {
my $self = shift;
my $table = shift;
- $table = $self->_quote($table) unless ref($table);
+ $table = $self->_quote($table);
$self->SUPER::update($table, @_);
}
+# Just quotes table names.
sub delete {
my $self = shift;
my $table = shift;
- $table = $self->_quote($table) unless ref($table);
+ $table = $self->_quote($table);
$self->SUPER::delete($table, @_);
}
sub _quote {
my ($self, $label) = @_;
return '' unless defined $label;
+ return $$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
-
projects / dbsrgits/DBIx-Class.git / blobdiff