X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=scpubgit%2FQ-Branch.git;a=blobdiff_plain;f=lib%2FSQL%2FAbstract%2FExtraClauses.pm;h=9c2784539387247910d19bae5ebb0f6646d86758;hp=78680dac1e573dfa6888ef7eb64b24806208e45b;hb=4979c509c66eb5c81887d3afe37de54f0988ad94;hpb=4a2c263bbfb6a7a2ac842fea2d3495d7ddfbbab1

diff --git a/lib/SQL/Abstract/ExtraClauses.pm b/lib/SQL/Abstract/ExtraClauses.pm
index 78680da..9c27845 100644
--- a/lib/SQL/Abstract/ExtraClauses.pm
+++ b/lib/SQL/Abstract/ExtraClauses.pm
@@ -1,47 +1,156 @@
 package SQL::Abstract::ExtraClauses;
 
-use strict;
-use warnings;
-use if $] < '5.010', 'MRO::Compat';
-use mro 'c3';
-use base qw(SQL::Abstract::Clauses);
-
-BEGIN { *puke = \&SQL::Abstract::puke }
-
-sub new {
-  my ($proto, @args) = @_;
-  my $new = $proto->next::method(@args);
-  $new->{clauses_of}{select} = [
-    @{$new->{clauses_of}{select}}, qw(group_by having)
-  ];
-  $new->{expand_clause}{'select.group_by'} = sub {
-    $_[0]->_expand_maybe_list_expr($_[1], -ident)
-  };
-  $new->{expand_clause}{'select.having'} = sub {
-    $_[0]->expand_expr($_[1])
+use Moo;
+
+has sqla => (
+  is => 'ro', init_arg => undef,
+  handles => [ qw(
+    expand_expr expand_maybe_list_expr render_aqt join_query_parts
+  ) ],
+);
+
+sub cb {
+  my ($self, $method, @args) = @_;
+  return sub {
+    local $self->{sqla} = shift;
+    $self->$method(@args, @_)
   };
-  $new->{expand}{from_list} = '_expand_from_list';
-  $new->{render}{from_list} = '_render_from_list';
-  $new->{expand}{join} = '_expand_join';
-  $new->{render}{join} = '_render_join';
-  $new->{expand_op}{as} = '_expand_op_as';
-  $new->{expand}{as} = '_expand_op_as';
-  $new->{render}{as} = '_render_as';
-  return $new;
 }
 
-sub _expand_select_clause_from {
-  my ($self, $from) = @_;
-  +(from => $self->_expand_from_list(undef, $from));
+sub register {
+  my ($self, @pairs) = @_;
+  my $sqla = $self->sqla;
+  while (my ($method, $cases) = splice(@pairs, 0, 2)) {
+    my @cases = @$cases;
+    while (my ($name, $case) = splice(@cases, 0, 2)) {
+      $sqla->$method($name, $self->cb($case));
+    }
+  }
+  return $self;
+}
+
+sub apply_to {
+  my ($self, $sqla) = @_;
+  $self = $self->new unless ref($self);
+  local $self->{sqla} = $sqla;
+  $self->register_extensions($sqla);
+}
+
+sub register_extensions {
+  my ($self, $sqla) = @_;
+
+  my @clauses = $sqla->clauses_of('select');
+  my @before_setop;
+  CLAUSE: foreach my $idx (0..$#clauses) {
+    if ($clauses[$idx] eq 'order_by') {
+      @before_setop = @clauses[0..$idx-1];
+      splice(@clauses, $idx, 0, qw(setop group_by having));
+      last CLAUSE;
+    }
+  }
+
+  die "Huh?" unless @before_setop;
+  $sqla->clauses_of(select => @clauses);
+
+  $sqla->clauses_of(update => sub {
+    my ($self, @clauses) = @_;
+    splice(@clauses, 2, 0, 'from');
+    @clauses;
+  });
+
+  $sqla->clauses_of(delete => sub {
+    my ($self, @clauses) = @_;
+    splice(@clauses, 1, 0, 'using');
+    @clauses;
+  });
+
+  $self->register(
+    (map +(
+      "${_}er" => [
+        do {
+          my $x = $_;
+          (map +($_ => "_${x}_${_}"), qw(join from_list alias))
+        }
+       ]
+    ), qw(expand render)),
+    binop_expander => [ as => '_expand_op_as' ],
+    renderer => [ as => '_render_as' ],
+    expander => [ cast => '_expand_cast' ],
+    clause_expanders => [
+      "select.from", '_expand_from_list',
+      'select.group_by'
+        => sub { $_[0]->expand_maybe_list_expr($_[2], -ident) },
+      'select.having'
+        => sub { $_[0]->expand_expr($_[2]) },
+      'update.from' => '_expand_from_list',
+      "update.target", '_expand_update_clause_target',
+      "update.update", '_expand_update_clause_target',
+      'delete.using' => '_expand_from_list',
+      'insert.rowvalues' => sub {
+        +(from => $_[0]->expand_expr({ -values => $_[2] }));
+      },
+      'insert.select' => sub {
+        +(from => $_[0]->expand_expr({ -select => $_[2] }));
+      },
+    ],
+  );
+
+  # set ops
+  $sqla->wrap_expander(select => sub {
+    $self->cb('_expand_select', $_[0], \@before_setop);
+  });
+
+  $self->register(
+    clause_renderer => [
+      'select.setop' => sub { $_[0]->render_aqt($_[2]) }
+    ],
+    expander => [ map +($_ => '_expand_setop'), qw(union intersect except) ],
+    renderer => [ map +($_ => '_render_setop'), qw(union intersect except) ],
+  );
+
+  my $setop_expander = $self->cb('_expand_clause_setop');
+
+  $sqla->clause_expanders(
+    map +($_ => $setop_expander),
+      map "select.${_}",
+        map +($_, "${_}_all", "${_}_distinct"),
+          qw(union intersect except)
+  );
+
+  foreach my $stmt (qw(select insert update delete)) {
+    $sqla->clauses_of($stmt => 'with', $sqla->clauses_of($stmt));
+    $self->register(
+      clause_expanders => [
+        "${stmt}.with" => '_expand_with',
+        "${stmt}.with_recursive" => '_expand_with',
+      ],
+      clause_renderer => [ "${stmt}.with" => '_render_with' ],
+    );
+  }
+
+  return $sqla;
+}
+
+sub _expand_select {
+  my ($self, $orig, $before_setop, @args) = @_;
+  my $exp = $self->sqla->$orig(@args);
+  return $exp unless my $setop = (my $sel = $exp->{-select})->{setop};
+  if (my @keys = grep $sel->{$_}, @$before_setop) {
+    my %inner; @inner{@keys} = delete @{$sel}{@keys};
+    unshift @{(values(%$setop))[0]{queries}},
+      { -select => \%inner };
+  }
+  return $exp;
 }
 
 sub _expand_from_list {
   my ($self, undef, $args) = @_;
   if (ref($args) eq 'HASH') {
+    return $args if $args->{-from_list};
     return { -from_list => [ $self->expand_expr($args) ] };
   }
   my @list;
-  my @args = ref($args) ? @$args : ($args);
+  my @args = ref($args) eq 'ARRAY' ? @$args : ($args);
   while (my $entry = shift @args) {
     if (!ref($entry) and $entry =~ /^-(.*)/) {
       if ($1 eq 'as') {
@@ -58,6 +167,7 @@ sub _expand_from_list {
     }
     push @list, $aqt;
   }
+  return $list[0] if @list == 1;
   return { -from_list => \@list };
 }
 
@@ -66,78 +176,403 @@ sub _expand_join {
   my %proto = (
     ref($args) eq 'HASH'
       ? %$args
-      : (to => $args->[0], @{$args}[1..$#$args])
+      : (to => @$args)
   );
   if (my $as = delete $proto{as}) {
-    $proto{to} = { -as => [ $proto{to}, ref($as) eq 'ARRAY' ? @$as : $as ] };
+    $proto{to} = $self->expand_expr(
+                   { -as => [ { -from_list => $proto{to} }, $as ] }
+                 );
   }
-  my %ret = map +($_ => $self->expand_expr($proto{$_}, -ident)),
-              sort keys %proto;
+  if (defined($proto{using}) and ref(my $using = $proto{using}) ne 'HASH') {
+    $proto{using} = [
+      map [ $self->expand_expr($_, -ident) ],
+        ref($using) eq 'ARRAY' ? @$using: $using
+    ];
+  }
+  my %ret = (
+    type => delete $proto{type},
+    to => $self->expand_expr({ -from_list => delete $proto{to} }, -ident)
+  );
+  %ret = (%ret,
+    map +($_ => $self->expand_expr($proto{$_}, -ident)),
+      sort keys %proto
+  );
   return +{ -join => \%ret };
 }
 
 sub _render_from_list {
-  my ($self, $list) = @_;
-  return $self->_join_parts(', ', map [ $self->render_aqt($_) ], @$list);
+  my ($self, undef, $list) = @_;
+  return $self->join_query_parts(', ', @$list);
 }
 
 sub _render_join {
-  my ($self, $args) = @_;
+  my ($self, undef, $args) = @_;
 
   my @parts = (
-    [ $self->render_aqt($args->{from}) ],
-    [ $self->_sqlcase(
-        ($args->{type}
-          ? join(' ', split '_', $args->{type}).' '
-          : ''
-        )
-        .'join'
-      )
-    ],
-    [ $self->render_aqt(
-        map +($_->{-ident} or $_->{-as} ? $_ : { -row => [ $_ ] }), $args->{to}
-    ) ],
+    $args->{from},
+    { -keyword => join '_', ($args->{type}||()), 'join' },
+    (map +($_->{-ident} || $_->{-as}
+      ? $_
+      : ('(', $self->render_aqt($_, 1), ')')),
+        map +(@{$_->{-from_list}||[]} == 1 ? $_->{-from_list}[0] : $_),
+          $args->{to}
+    ),
     ($args->{on} ? (
-      [ $self->_sqlcase('on') ],
-      [ $self->render_aqt($args->{on}) ],
+      { -keyword => 'on' },
+      $args->{on},
     ) : ()),
     ($args->{using} ? (
-      [ $self->_sqlcase('using') ],
-      [ $self->render_aqt($args->{using}) ],
+      { -keyword => 'using' },
+      '(', $args->{using}, ')',
     ) : ()),
   );
-  return $self->_join_parts(' ', @parts);
+  return $self->join_query_parts(' ', @parts);
 }
 
 sub _expand_op_as {
   my ($self, undef, $vv, $k) = @_;
-  my @as = map $self->expand_expr($_, -ident),
-             (defined($k) ? ($k) : ()), ref($vv) eq 'ARRAY' ? @$vv : $vv;
-  return { -as => \@as };
+  my @vv = (ref($vv) eq 'ARRAY' ? @$vv : $vv);
+  my $ik = $self->expand_expr($k, -ident);
+  return +{ -as => [ $ik, $self->expand_expr($vv[0], -ident) ] }
+    if @vv == 1 and ref($vv[0]) eq 'HASH';
+
+  my @as = map $self->expand_expr($_, -ident), @vv;
+  return { -as => [ $ik, $self->expand_expr({ -alias => \@as }) ] };
 }
 
 sub _render_as {
-  my ($self, $args) = @_;
-  my ($thing, $as, @cols) = @$args;
-  return $self->_join_parts(
+  my ($self, undef, $args) = @_;
+  my ($thing, $alias) = @$args;
+  return $self->join_query_parts(
     ' ',
-    [ $self->render_aqt(
-        map +($_->{-ident} ? $_ : { -row => [ $_ ] }), $thing
-    ) ],
-    [ $self->_sqlcase('as') ],
-    (@cols
-      ? [ $self->_join_parts('',
-            [ $self->render_aqt($as) ],
-            [ '(' ],
-            [ $self->_join_parts(
-                ', ',
-                map [ $self->render_aqt($_) ], @cols
-            ) ],
-            [ ')' ],
-        ) ]
-      : [ $self->render_aqt($as) ]
-    ),
+    $thing,
+    { -keyword => 'as' },
+    $alias,
+  );
+}
+
+sub _render_alias {
+  my ($self, undef, $args) = @_;
+  my ($as, @cols) = @$args;
+  return (@cols
+    ? $self->join_query_parts('',
+         $as,
+         '(',
+         $self->join_query_parts(
+           ', ',
+           @cols
+         ),
+         ')',
+      )
+    : $self->render_aqt($as)
+  );
+}
+
+sub _expand_update_clause_target {
+  my ($self, undef, $target) = @_;
+  +(target => $self->_expand_from_list(undef, $target));
+}
+
+sub _expand_cast {
+  my ($self, undef, $thing) = @_;
+  return { -func => [ cast => $thing ] } if ref($thing) eq 'HASH';
+  my ($cast, $to) = @{$thing};
+  +{ -func => [ cast => { -as => [
+    $self->expand_expr($cast),
+    $self->expand_expr($to, -ident),
+  ] } ] };
+}
+
+sub _expand_alias {
+  my ($self, undef, $args) = @_;
+  if (ref($args) eq 'HASH' and my $alias = $args->{-alias}) {
+    $args = $alias;
+  }
+  my @parts = map $self->expand_expr($_, -ident),
+                ref($args) eq 'ARRAY' ? @{$args} : $args;
+  return $parts[0] if @parts == 1;
+  return { -alias => \@parts };
+}
+
+sub _expand_with {
+  my ($self, $name, $with) = @_;
+  my (undef, $type) = split '_', $name;
+  if (ref($with) eq 'HASH') {
+    return +{
+      %$with,
+      queries => [
+        map +[
+          $self->expand_expr({ -alias => $_->[0] }, -ident),
+          $self->expand_expr($_->[1]),
+        ], @{$with->{queries}}
+      ]
+    }
+  }
+  my @with = @$with;
+  my @exp;
+  while (my ($alias, $query) = splice @with, 0, 2) {
+    push @exp, [
+      $self->expand_expr({ -alias => $alias }, -ident),
+      $self->expand_expr($query)
+    ];
+  }
+  return +(with => { ($type ? (type => $type) : ()), queries => \@exp });
+}
+
+sub _render_with {
+  my ($self, undef, $with) = @_;
+  my $q_part = $self->join_query_parts(', ',
+    map {
+      my ($alias, $query) = @$_;
+      $self->join_query_parts(' ',
+          $alias,
+          { -keyword => 'as' },
+          $query,
+      )
+    } @{$with->{queries}}
+  );
+  return $self->join_query_parts(' ',
+    { -keyword => join '_', 'with', ($with->{type}||'') },
+    $q_part,
   );
 }
 
+sub _expand_setop {
+  my ($self, $setop, $args) = @_;
+  +{ "-${setop}" => {
+       %$args,
+       queries => [ map $self->expand_expr($_), @{$args->{queries}} ],
+  } };
+}
+
+sub _render_setop {
+  my ($self, $setop, $args) = @_;
+  $self->join_query_parts(
+    { -keyword => ' '.join('_', $setop, ($args->{type}||())).' ' },
+    @{$args->{queries}}
+  );
+}
+
+sub _expand_clause_setop {
+  my ($self, $setop, $args) = @_;
+  my ($op, $type) = split '_', $setop;
+  +(setop => $self->expand_expr({
+    "-${op}" => {
+      ($type ? (type => $type) : ()),
+      queries => (ref($args) eq 'ARRAY' ? $args : [ $args ])
+    }
+  }));
+}
+
 1;
+
+__END__
+
+=head1 NAME
+
+SQL::Abstract::ExtraClauses - new/experimental additions to L<SQL::Abstract>
+
+=head1 SYNOPSIS
+
+  my $sqla = SQL::Abstract->new;
+  SQL::Abstract::ExtraClauses->apply_to($sqla);
+
+=head1 METHODS
+
+=head2 apply_to
+
+Applies the plugin to an L<SQL::Abstract> object.
+
+=head2 register_extensions
+
+Registers the extensions described below
+
+=head2 cb
+
+For plugin authors, creates a callback to call a method on the plugin.
+
+=head2 register
+
+For plugin authors, registers callbacks more easily.
+
+=head2 sqla
+
+Available only during plugin callback executions, contains the currently
+active L<SQL::Abstract> object.
+
+=head1 NODE TYPES
+
+=head2 alias
+
+Represents a table alias. Expands name and column names with ident as default.
+
+  # expr
+  { -alias => [ 't', 'x', 'y', 'z' ] }
+
+  # aqt
+  { -alias => [
+      { -ident => [ 't' ] }, { -ident => [ 'x' ] },
+      { -ident => [ 'y' ] }, { -ident => [ 'z' ] },
+  ] }
+
+  # query
+  t(x, y, z)
+  []
+
+=head2 as
+
+Represents an sql AS. LHS is expanded with ident as default, RHS is treated
+as a list of arguments for the alias node.
+
+  # expr
+  { foo => { -as => 'bar' } }
+
+  # aqt
+  { -as => [ { -ident => [ 'foo' ] }, { -ident => [ 'bar' ] } ] }
+
+  # query
+  foo AS bar
+  []
+
+  # expr
+  { -as => [ { -select => { _ => 'blah' } }, 't', 'blah' ] }
+
+  # aqt
+  { -as => [
+      { -select =>
+          { select => { -op => [ ',', { -ident => [ 'blah' ] } ] } }
+      },
+      { -alias => [ { -ident => [ 't' ] }, { -ident => [ 'blah' ] } ] },
+  ] }
+
+  # query
+  (SELECT blah) AS t(blah)
+  []
+
+=head2 cast
+
+  # expr
+  { -cast => [ { -ident => 'birthday' }, 'date' ] }
+
+  # aqt
+  { -func => [
+      'cast', {
+        -as => [ { -ident => [ 'birthday' ] }, { -ident => [ 'date' ] } ]
+      },
+  ] }
+
+  # query
+  CAST(birthday AS date)
+  []
+
+=head2 join
+
+If given an arrayref, pretends it was given a hashref with the first
+element of the arrayref as the value for 'to' and the remaining pairs copied.
+
+Given a hashref, the 'as' key is if presented expanded to wrap the 'to'.
+
+If present the 'using' key is expanded as a list of idents.
+
+Known keys are: 'from' (the left hand side), 'type' ('left', 'right', or
+nothing), 'to' (the right hand side), 'on' and 'using'.
+
+  # expr
+  { -join => {
+      from => 'lft',
+      on => { 'lft.bloo' => { '>' => 'rgt.blee' } },
+      to => 'rgt',
+      type => 'left',
+  } }
+
+  # aqt
+  { -join => {
+      from => { -ident => [ 'lft' ] },
+      on => { -op => [
+          '>', { -ident => [ 'lft', 'bloo' ] },
+          { -ident => [ 'rgt', 'blee' ] },
+      ] },
+      to => { -ident => [ 'rgt' ] },
+      type => 'left',
+  } }
+
+  # query
+  lft LEFT JOIN rgt ON lft.bloo > rgt.blee
+  []
+
+=head2 from_list
+
+List of components of the FROM clause; -foo type elements indicate a pair
+with the next element; this is easiest if I show you:
+
+  # expr
+  { -from_list => [
+      't1', -as => 'table_one', -join =>
+      [ 't2', 'on', { 'table_one.x' => 't2.x' } ],
+  ] }
+
+  # aqt
+  { -join => {
+      from =>
+        {
+          -as => [ { -ident => [ 't1' ] }, { -ident => [ 'table_one' ] } ]
+        },
+      on => { -op => [
+          '=', { -ident => [ 'table_one', 'x' ] },
+          { -ident => [ 't2', 'x' ] },
+      ] },
+      to => { -ident => [ 't2' ] },
+      type => undef,
+  } }
+
+  # query
+  t1 AS table_one JOIN t2 ON table_one.x = t2.x
+  []
+
+Or with using:
+
+  # expr
+  { -from_list =>
+      [ 't1', -as => 'table_one', -join => [ 't2', 'using', [ 'x' ] ] ]
+  }
+
+  # aqt
+  { -join => {
+      from =>
+        {
+          -as => [ { -ident => [ 't1' ] }, { -ident => [ 'table_one' ] } ]
+        },
+      to => { -ident => [ 't2' ] },
+      type => undef,
+      using =>
+        { -op => [ 'or', { -op => [ 'or', { -ident => [ 'x' ] } ] } ] },
+  } }
+
+  # query
+  t1 AS table_one JOIN t2 USING ( x )
+  []
+
+With oddities:
+
+  # expr
+  { -from_list => [
+      'x', -join =>
+      [ [ 'y', -join => [ 'z', 'type', 'left' ] ], 'type', 'left' ],
+  ] }
+
+  # aqt
+  { -join => {
+      from => { -ident => [ 'x' ] },
+      to => { -join => {
+          from => { -ident => [ 'y' ] },
+          to => { -ident => [ 'z' ] },
+          type => 'left',
+      } },
+      type => 'left',
+  } }
+
+  # query
+  x LEFT JOIN ( y LEFT JOIN z )
+  []
+
+=cut