X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FSQLAHacks.pm;h=ba892644f637a6a455768f81ee577c252f6a129a;hb=64c7c000587e6e6dccb9fc6330a66dcebd1f3695;hp=65e1a4f8b286b2e008dfa0813660f0073874643a;hpb=04ebc6f4d9b90ad04258ef202c3879b509dd0b09;p=dbsrgits%2FDBIx-Class-Historic.git

diff --git a/lib/DBIx/Class/SQLAHacks.pm b/lib/DBIx/Class/SQLAHacks.pm
index 65e1a4f..ba89264 100644
--- a/lib/DBIx/Class/SQLAHacks.pm
+++ b/lib/DBIx/Class/SQLAHacks.pm
@@ -4,7 +4,28 @@ package # Hide from PAUSE
 use base qw/SQL::Abstract::Limit/;
 use strict;
 use warnings;
-use Carp::Clan qw/^DBIx::Class/;
+use Carp::Clan qw/^DBIx::Class|^SQL::Abstract/;
+
+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 {
+
+      local $Carp::CarpLevel = 1;   # even though Carp::Clan ignores this, $orig will not
+
+      if (Carp::longmess() =~ /DBIx::Class::SQLAHacks::[\w]+\(\) called/) {
+        __PACKAGE__->can($f)->(@_);
+      }
+      else {
+        $orig->(@_);
+      }
+    }
+  }
+}
 
 sub new {
   my $self = shift->SUPER::new(@_);
@@ -67,11 +88,7 @@ sub _where_field_BETWEEN {
   return $self->SUPER::_where_field_BETWEEN ($lhs, $op, $rhs);
 }
 
-
-
-# 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
+# Slow but ANSI standard Limit/Offset support. DB2 uses this
 sub _RowNumberOver {
   my ($self, $sql, $order, $rows, $offset ) = @_;
 
@@ -94,30 +111,199 @@ SQL
   return $sql;
 }
 
+# Crappy Top based Limit/Offset support. MSSQL uses this currently,
+# but may have to switch to RowNumberOver one day
+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 || '.';
+  $name_sep = "\Q$name_sep\E";
+  my $col_re = qr/ ^ (?: (.+) $name_sep )? ([^$name_sep]+) $ /x;
+
+  # 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} > 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 = [ $self->_order_by_chunks ($order->{order_by}) ];
+  my $limit_order = [ @$req_order ? @$req_order : $self->_order_by_chunks ($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);
+
+  # generate the rest
+  delete $order->{$_} for qw/order_by _virtual_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;
+  }
+
+  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
+    ) AS inner_sel
+    $order_by_outer
+SQL
+
+  }
+
+  if ($order_by_requested) {
+    $sql = <<"SQL";
+
+    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,
 #  without digging into things too deeply
-use Scalar::Util 'blessed';
 sub _find_syntax {
   my ($self, $syntax) = @_;
-  
-  # 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
-  my $dbhname = blessed($syntax) ? $syntax->{Driver}{Name} : $syntax;
-  if(ref($self) && $dbhname) {
-    if ($dbhname eq 'DB2') {
-      return 'RowNumberOver';
-    }
-  }
-  
-  $self->{_cached_syntax} ||= $self->SUPER::_find_syntax($syntax);
+  return $self->{_cached_syntax} ||= $self->SUPER::_find_syntax($syntax);
 }
 
+my $for_syntax = {
+  update => 'FOR UPDATE',
+  shared => 'FOR SHARE',
+};
 sub select {
   my ($self, $table, $fields, $where, $order, @rest) = @_;
-  local $self->{having_bind} = [];
-  local $self->{from_bind} = [];
+
+  $self->{"${_}_bind"} = [] for (qw/having from order/);
 
   if (ref $table eq 'SCALAR') {
     $table = $$table;
@@ -133,22 +319,25 @@ sub select {
   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;
 }
 
 sub insert {
   my $self = shift;
   my $table = shift;
   $table = $self->_quote($table) unless ref($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, @_);
 }
 
@@ -221,78 +410,46 @@ sub _recurse_fields {
 }
 
 sub _order_by {
-  my $self = shift;
-  my $ret = '';
-  my @extra;
-  if (ref $_[0] eq 'HASH') {
-    if (defined $_[0]->{group_by}) {
+  my ($self, $arg) = @_;
+
+  if (ref $arg eq 'HASH' and keys %$arg and not grep { $_ =~ /^-(?:desc|asc)/i } keys %$arg ) {
+
+    my $ret = '';
+
+    if (defined $arg->{group_by}) {
       $ret = $self->_sqlcase(' group by ')
-        .$self->_recurse_fields($_[0]->{group_by}, { no_rownum_hack => 1 });
+        .$self->_recurse_fields($arg->{group_by}, { no_rownum_hack => 1 });
     }
-    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]);
+
+    if (defined $arg->{order_by}) {
+      my ($frag, @bind) = $self->SUPER::_order_by($arg->{order_by});
+      push(@{$self->{order_bind}}, @bind);
+      $ret .= $frag;
     }
-  } 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 $ret;
+  }
+  else {
+    my ($sql, @bind) = $self->SUPER::_order_by ($arg);
+    push(@{$self->{order_bind}}, @bind);
+    return $sql;
   }
-  return $ret;
 }
 
 sub _order_directions {
   my ($self, $order) = @_;
-  $order = $order->{order_by} if ref $order eq 'HASH';
-  if (ref $order eq 'HASH') {
-    $order = [$self->_order_directions_hash($order)];
-  } elsif (ref $order eq 'ARRAY') {
-    $order = [map {
-      if (ref $_ eq 'HASH') {
-        $self->_order_directions_hash($_);
-      } else {
-        $_;
-      }
-    } @{ $order }];
-  }
-  return $self->SUPER::_order_directions($order);
-}
 
-sub _order_directions_hash {
-  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 {
@@ -340,8 +497,11 @@ sub _recurse_from {
 
 sub _fold_sqlbind {
   my ($self, $sqlbind) = @_;
-  my $sql = shift @$$sqlbind;
-  push @{$self->{from_bind}}, @$$sqlbind;
+
+  my @sqlbind = @$$sqlbind; # copy
+  my $sql = shift @sqlbind;
+  push @{$self->{from_bind}}, @sqlbind;
+
   return $sql;
 }