From: Peter Rabbitson <ribasushi@cpan.org>
Date: Sat, 25 Feb 2012 14:36:43 +0000 (+0100)
Subject: Simplify code of GenericSubQ limit dialect
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=528e717e3715d0f68e790542306161612cae4fef;p=dbsrgits%2FDBIx-Class-Historic.git

Simplify code of GenericSubQ limit dialect
---

diff --git a/lib/DBIx/Class/SQLMaker/LimitDialects.pm b/lib/DBIx/Class/SQLMaker/LimitDialects.pm
index 5c2c002..ac145c3 100644
--- a/lib/DBIx/Class/SQLMaker/LimitDialects.pm
+++ b/lib/DBIx/Class/SQLMaker/LimitDialects.pm
@@ -562,63 +562,29 @@ sub _GenericSubQ {
   my $root_rsrc = $rs_attrs->{_rsroot_rsrc};
   my $root_tbl_name = $root_rsrc->name;
 
-  my ($order_by, @rest) = do {
+  my ($first_order_by) = do {
     local $self->{quote_char};
-    $self->_order_by_chunks ($rs_attrs->{order_by})
-  };
-
-  unless (
-    $order_by
-      &&
-    ! @rest
-      &&
-    ( ! ref $order_by
-        ||
-      ( ref $order_by eq 'ARRAY' and @$order_by == 1 )
-    )
-  ) {
-    $self->throw_exception (
-      'Generic Subquery Limit does not work on resultsets without an order, or resultsets '
-    . 'with complex order criteria (multicolumn and/or functions). Provide a single, '
-    . 'unique-column order criteria.'
-    );
-  }
-
-  ($order_by) = @$order_by if ref $order_by;
+    map { ref $_ ? $_->[0] : $_ } $self->_order_by_chunks ($rs_attrs->{order_by})
+  } or $self->throw_exception (
+    'Generic Subquery Limit does not work on resultsets without an order. Provide a single, '
+  . 'unique-column order criteria.'
+  );
 
-  $order_by =~ s/\s+ ( ASC|DESC ) \s* $//ix;
+  $first_order_by =~ s/\s+ ( ASC|DESC ) \s* $//ix;
   my $direction = lc ($1 || 'asc');
 
-  my ($unq_sort_col) = $order_by =~ /(?:^|\.)([^\.]+)$/;
-
-  my $inf = $root_rsrc->storage->_resolve_column_info (
-    $rs_attrs->{from}, [$order_by, $unq_sort_col]
-  );
-
-  my $ord_colinfo = $inf->{$order_by} || $self->throw_exception("Unable to determine source of order-criteria '$order_by'");
+  my ($first_ord_alias, $first_ord_col) = $first_order_by =~ /^ (?: ([^\.]+) \. )? ([^\.]+) $/x;
 
-  if ($ord_colinfo->{-result_source}->name ne $root_tbl_name) {
-    $self->throw_exception(sprintf
-      "Generic Subquery Limit order criteria can be only based on the root-source '%s'"
-    . " (aliased as '%s')", $root_rsrc->source_name, $rs_attrs->{alias},
-    );
-  }
+  $self->throw_exception(sprintf
+    "Generic Subquery Limit order criteria can be only based on the root-source '%s'"
+  . " (aliased as '%s')", $root_rsrc->source_name, $rs_attrs->{alias},
+  ) if ($first_ord_alias and $first_ord_alias ne $rs_attrs->{alias});
 
-  # make sure order column is qualified
-  $order_by = "$rs_attrs->{alias}.$order_by"
-    unless $order_by =~ /^$rs_attrs->{alias}\./;
+  $first_ord_alias ||= $rs_attrs->{alias};
 
-  my $is_u;
-  my $ucs = { $root_rsrc->unique_constraints };
-  for (values %$ucs ) {
-    if (@$_ == 1 && "$rs_attrs->{alias}.$_->[0]" eq $order_by) {
-      $is_u++;
-      last;
-    }
-  }
   $self->throw_exception(
-    "Generic Subquery Limit order criteria column '$order_by' must be unique (no unique constraint found)"
-  ) unless $is_u;
+    "Generic Subquery Limit first order criteria '$first_ord_col' must be unique"
+  ) unless $root_rsrc->_identifying_column_set([$first_ord_col]);
 
   my ($stripped_sql, $in_sel, $out_sel, $alias_map, $extra_order_sel)
     = $self->_subqueried_limit_attrs ($sql, $rs_attrs);
@@ -660,8 +626,8 @@ $order_sql
     $rs_attrs->{alias},
     $root_tbl_name,
     $count_tbl_alias,
-    "$count_tbl_alias.$unq_sort_col",
-    $order_by,
+    "$count_tbl_alias.$first_ord_col",
+    "$first_ord_alias.$first_ord_col",
   ));
 }
 
diff --git a/t/sqlmaker/limit_dialects/generic_subq.t b/t/sqlmaker/limit_dialects/generic_subq.t
index 21a38d6..8b4b056 100644
--- a/t/sqlmaker/limit_dialects/generic_subq.t
+++ b/t/sqlmaker/limit_dialects/generic_subq.t
@@ -142,9 +142,9 @@ is_deeply (
 
 {
   $rs = $schema->resultset('Artist')->search({}, {
-    columns => 'name',
+    columns => 'artistid',
     offset => 1,
-    order_by => 'name',
+    order_by => 'artistid',
   });
   local $rs->result_source->{name} = "weird \n newline/multi \t \t space containing \n table";