# 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 $select = $1;
+ 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 (@outer_select, %col_index);
- for my $selected_col (@{$self->{_dbic_rs_attrs}{select}}) {
+ my $name_sep = $self->name_sep || '.';
+ $name_sep = "\Q$name_sep\E";
+ my $col_re = qr/ ^ (?: (.+) $name_sep )? ([^$name_sep]+) $ /x;
- my $new_colname;
+ # construct the new select lists, rename(alias) some columns if necessary
+ my (@outer_select, @inner_select, %seen_names, %col_aliases, %outer_col_aliases);
- if (ref $selected_col) {
- $new_colname = $self->_quote ('column_' . (@outer_select + 1) );
- }
- else {
- my $quoted_col = $self->_quote ($selected_col);
+ for (@{$self->{_dbic_rs_attrs}{select}}) {
+ next if ref $_;
+ my ($table, $orig_colname) = ( $_ =~ $col_re );
+ next unless $table;
+ $seen_names{$orig_colname}++;
+ }
- my $name_sep = $self->name_sep || '.';
- $name_sep = "\Q$name_sep\E";
+ for my $i (0 .. $#sql_select) {
- my ($table, $orig_colname) = ( $selected_col =~ / (?: (.+) $name_sep )? ([^$name_sep]+) $ /x );
- $new_colname = $self->_quote ("${table}__${orig_colname}");
+ my $colsel_arg = $self->{_dbic_rs_attrs}{select}[$i];
+ my $colsel_sql = $sql_select[$i];
- $select =~ s/(\Q$quoted_col\E|\Q$selected_col\E)/"$1 AS $new_colname"/e;
+ # this may or may not work (in case of a scalarref or something)
+ my ($table, $orig_colname) = ( $colsel_arg =~ $col_re );
- # record qualified name if available (should be)
- $col_index{$selected_col} = $new_colname if $table;
+ 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} > 1) ) {
+ $quoted_alias = $self->_quote ("${table}__${orig_colname}");
+ }
- # record unqialified name, undef if a duplicate is found
- if (exists $col_index{$orig_colname}) {
- $col_index{$orig_colname} = undef;
- }
- else {
- $col_index{$orig_colname} = $new_colname;
- }
+ # we did rename - make a record and adjust
+ if ($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,
+ );
}
- push @outer_select, $new_colname;
+ # 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'
my $req_order = [ $self->_order_by_chunks ($order->{order_by}) ];
my $limit_order = [ @$req_order ? @$req_order : $self->_order_by_chunks ($order->{_virtual_order_by}) ];
-
- # normalize all column names in order by
- # no copies, just aliasing ($_)
- for ($req_order, $limit_order) {
- for ( @{$_ || []} ) {
- $_ = $col_index{$_} if $col_index{$_};
- }
- }
-
+ 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 $order->{$_} for qw/order_by _virtual_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";
+ }
- my $last = $rows + $offset;
- $sql = <<"SQL";
+ # 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;
+ }
+
+ 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 $select $sql $grpby_having $order_by_inner
+ $sql
) AS inner_sel
$order_by_outer
SQL
- if (@$req_order) {
- my $order_by_requested = $self->_order_by ($req_order);
+ }
+ if ($order_by_requested) {
$sql = <<"SQL";
- SELECT $outer_select FROM
- ( $sql ) AS outer_sel
- $order_by_requested;
+ SELECT $outer_select FROM
+ ( $sql ) AS outer_sel
+ $order_by_requested;
SQL
}
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 unqialified 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,
projects / dbsrgits/DBIx-Class-Historic.git / blobdiff