diff options
Diffstat (limited to 'activerecord/lib/arel/visitors')
| -rw-r--r-- | activerecord/lib/arel/visitors/depth_first.rb | 3 | ||||
| -rw-r--r-- | activerecord/lib/arel/visitors/dot.rb | 2 | ||||
| -rw-r--r-- | activerecord/lib/arel/visitors/mssql.rb | 7 | ||||
| -rw-r--r-- | activerecord/lib/arel/visitors/mysql.rb | 77 | ||||
| -rw-r--r-- | activerecord/lib/arel/visitors/to_sql.rb | 130 |
5 files changed, 118 insertions, 101 deletions
diff --git a/activerecord/lib/arel/visitors/depth_first.rb b/activerecord/lib/arel/visitors/depth_first.rb index bcf8f8f980..8f65d303ac 100644 --- a/activerecord/lib/arel/visitors/depth_first.rb +++ b/activerecord/lib/arel/visitors/depth_first.rb @@ -34,7 +34,6 @@ module Arel # :nodoc: all alias :visit_Arel_Nodes_Ordering :unary alias :visit_Arel_Nodes_Ascending :unary alias :visit_Arel_Nodes_Descending :unary - alias :visit_Arel_Nodes_Top :unary alias :visit_Arel_Nodes_UnqualifiedColumn :unary def function(o) @@ -136,12 +135,10 @@ module Arel # :nodoc: all alias :visit_Arel_Nodes_True :terminal alias :visit_Arel_Nodes_False :terminal alias :visit_BigDecimal :terminal - alias :visit_Bignum :terminal alias :visit_Class :terminal alias :visit_Date :terminal alias :visit_DateTime :terminal alias :visit_FalseClass :terminal - alias :visit_Fixnum :terminal alias :visit_Float :terminal alias :visit_Integer :terminal alias :visit_NilClass :terminal diff --git a/activerecord/lib/arel/visitors/dot.rb b/activerecord/lib/arel/visitors/dot.rb index d352b81914..9054f0159b 100644 --- a/activerecord/lib/arel/visitors/dot.rb +++ b/activerecord/lib/arel/visitors/dot.rb @@ -81,7 +81,6 @@ module Arel # :nodoc: all alias :visit_Arel_Nodes_Not :unary alias :visit_Arel_Nodes_Offset :unary alias :visit_Arel_Nodes_On :unary - alias :visit_Arel_Nodes_Top :unary alias :visit_Arel_Nodes_UnqualifiedColumn :unary alias :visit_Arel_Nodes_Preceding :unary alias :visit_Arel_Nodes_Following :unary @@ -212,7 +211,6 @@ module Arel # :nodoc: all alias :visit_TrueClass :visit_String alias :visit_FalseClass :visit_String alias :visit_Integer :visit_String - alias :visit_Fixnum :visit_String alias :visit_BigDecimal :visit_String alias :visit_Float :visit_String alias :visit_Symbol :visit_String diff --git a/activerecord/lib/arel/visitors/mssql.rb b/activerecord/lib/arel/visitors/mssql.rb index 9aedc51d15..d564e19089 100644 --- a/activerecord/lib/arel/visitors/mssql.rb +++ b/activerecord/lib/arel/visitors/mssql.rb @@ -12,13 +12,6 @@ module Arel # :nodoc: all private - # `top` wouldn't really work here. I.e. User.select("distinct first_name").limit(10) would generate - # "select top 10 distinct first_name from users", which is invalid query! it should be - # "select distinct top 10 first_name from users" - def visit_Arel_Nodes_Top(o) - "" - end - def visit_Arel_Visitors_MSSQL_RowNumber(o, collector) collector << "ROW_NUMBER() OVER (ORDER BY " inject_join(o.children, collector, ", ") << ") as _row_num" diff --git a/activerecord/lib/arel/visitors/mysql.rb b/activerecord/lib/arel/visitors/mysql.rb index 37bfb661f0..32f6705d04 100644 --- a/activerecord/lib/arel/visitors/mysql.rb +++ b/activerecord/lib/arel/visitors/mysql.rb @@ -9,20 +9,20 @@ module Arel # :nodoc: all collector << "( " end - collector = case o.left - when Arel::Nodes::Union - visit_Arel_Nodes_Union o.left, collector, true - else - visit o.left, collector + case o.left + when Arel::Nodes::Union + visit_Arel_Nodes_Union o.left, collector, true + else + visit o.left, collector end collector << " UNION " - collector = case o.right - when Arel::Nodes::Union - visit_Arel_Nodes_Union o.right, collector, true - else - visit o.right, collector + case o.right + when Arel::Nodes::Union + visit_Arel_Nodes_Union o.right, collector, true + else + visit o.right, collector end if suppress_parens @@ -37,6 +37,10 @@ module Arel # :nodoc: all visit o.expr, collector end + def visit_Arel_Nodes_UnqualifiedColumn(o, collector) + visit o.expr, collector + end + ### # :'( # http://dev.mysql.com/doc/refman/5.0/en/select.html#id3482214 @@ -52,28 +56,6 @@ module Arel # :nodoc: all super end - def visit_Arel_Nodes_UpdateStatement(o, collector) - collector << "UPDATE " - collector = visit o.relation, collector - - unless o.values.empty? - collector << " SET " - collector = inject_join o.values, collector, ", " - end - - unless o.wheres.empty? - collector << " WHERE " - collector = inject_join o.wheres, collector, " AND " - end - - unless o.orders.empty? - collector << " ORDER BY " - collector = inject_join o.orders, collector, ", " - end - - maybe_visit o.limit, collector - end - def visit_Arel_Nodes_Concat(o, collector) collector << " CONCAT(" visit o.left, collector @@ -82,6 +64,37 @@ module Arel # :nodoc: all collector << ") " collector end + + # In the simple case, MySQL allows us to place JOINs directly into the UPDATE + # query. However, this does not allow for LIMIT, OFFSET and ORDER. To support + # these, we must use a subquery. + def prepare_update_statement(o) + if o.offset || has_join_sources?(o) && has_limit_or_offset_or_orders?(o) + super + else + o + end + end + alias :prepare_delete_statement :prepare_update_statement + + # MySQL is too stupid to create a temporary table for use subquery, so we have + # to give it some prompting in the form of a subsubquery. + def build_subselect(key, o) + subselect = super + + # Materialize subquery by adding distinct + # to work with MySQL 5.7.6 which sets optimizer_switch='derived_merge=on' + unless has_limit_or_offset_or_orders?(subselect) + core = subselect.cores.last + core.set_quantifier = Arel::Nodes::Distinct.new + end + + Nodes::SelectStatement.new.tap do |stmt| + core = stmt.cores.last + core.froms = Nodes::Grouping.new(subselect).as("__active_record_temp") + core.projections = [Arel.sql(quote_column_name(key.name))] + end + end end end end diff --git a/activerecord/lib/arel/visitors/to_sql.rb b/activerecord/lib/arel/visitors/to_sql.rb index 5986fd5576..8e56fb55a2 100644 --- a/activerecord/lib/arel/visitors/to_sql.rb +++ b/activerecord/lib/arel/visitors/to_sql.rb @@ -67,55 +67,39 @@ module Arel # :nodoc: all @connection = connection end - def compile(node, &block) - accept(node, Arel::Collectors::SQLString.new, &block).value + def compile(node, collector = Arel::Collectors::SQLString.new) + accept(node, collector).value end private def visit_Arel_Nodes_DeleteStatement(o, collector) - collector << "DELETE FROM " - collector = visit o.relation, collector - if o.wheres.any? - collector << WHERE - collector = inject_join o.wheres, collector, AND + o = prepare_delete_statement(o) + + if has_join_sources?(o) + collector << "DELETE " + visit o.relation.left, collector + collector << " FROM " + else + collector << "DELETE FROM " end + collector = visit o.relation, collector + collect_nodes_for o.wheres, collector, " WHERE ", " AND " + collect_nodes_for o.orders, collector, " ORDER BY " maybe_visit o.limit, collector end - # FIXME: we should probably have a 2-pass visitor for this - def build_subselect(key, o) - stmt = Nodes::SelectStatement.new - core = stmt.cores.first - core.froms = o.relation - core.wheres = o.wheres - core.projections = [key] - stmt.limit = o.limit - stmt.orders = o.orders - stmt - end - def visit_Arel_Nodes_UpdateStatement(o, collector) - if o.orders.empty? && o.limit.nil? - wheres = o.wheres - else - wheres = [Nodes::In.new(o.key, [build_subselect(o.key, o)])] - end + o = prepare_update_statement(o) collector << "UPDATE " collector = visit o.relation, collector - unless o.values.empty? - collector << " SET " - collector = inject_join o.values, collector, ", " - end - - unless wheres.empty? - collector << " WHERE " - collector = inject_join wheres, collector, " AND " - end + collect_nodes_for o.values, collector, " SET " - collector + collect_nodes_for o.wheres, collector, " WHERE ", " AND " + collect_nodes_for o.orders, collector, " ORDER BY " + maybe_visit o.limit, collector end def visit_Arel_Nodes_InsertStatement(o, collector) @@ -237,8 +221,6 @@ module Arel # :nodoc: all def visit_Arel_Nodes_SelectCore(o, collector) collector << "SELECT" - collector = maybe_visit o.top, collector - collector = maybe_visit o.set_quantifier, collector collect_nodes_for o.projections, collector, SPACE @@ -250,10 +232,7 @@ module Arel # :nodoc: all collect_nodes_for o.wheres, collector, WHERE, AND collect_nodes_for o.groups, collector, GROUP_BY - unless o.havings.empty? - collector << " HAVING " - inject_join o.havings, collector, AND - end + collect_nodes_for o.havings, collector, " HAVING ", AND collect_nodes_for o.windows, collector, WINDOW collector @@ -262,11 +241,7 @@ module Arel # :nodoc: all def collect_nodes_for(nodes, collector, spacer, connector = COMMA) unless nodes.empty? collector << spacer - len = nodes.length - 1 - nodes.each_with_index do |x, i| - collector = visit(x, collector) - collector << connector unless len == i - end + inject_join nodes, collector, connector end end @@ -321,10 +296,7 @@ module Arel # :nodoc: all def visit_Arel_Nodes_Window(o, collector) collector << "(" - if o.partitions.any? - collector << "PARTITION BY " - collector = inject_join o.partitions, collector, ", " - end + collect_nodes_for o.partitions, collector, "PARTITION BY " if o.orders.any? collector << SPACE if o.partitions.any? @@ -405,11 +377,6 @@ module Arel # :nodoc: all visit o.expr, collector end - # FIXME: this does nothing on most databases, but does on MSSQL - def visit_Arel_Nodes_Top(o, collector) - collector - end - def visit_Arel_Nodes_Lock(o, collector) visit o.expr, collector end @@ -612,6 +579,10 @@ module Arel # :nodoc: all end def visit_Arel_Nodes_In(o, collector) + if Array === o.right && !o.right.empty? + o.right.keep_if { |value| boundable?(value) } + end + if Array === o.right && o.right.empty? collector << "1=0" else @@ -622,6 +593,10 @@ module Arel # :nodoc: all end def visit_Arel_Nodes_NotIn(o, collector) + if Array === o.right && !o.right.empty? + o.right.keep_if { |value| boundable?(value) } + end + if Array === o.right && o.right.empty? collector << "1=1" else @@ -644,7 +619,7 @@ module Arel # :nodoc: all def visit_Arel_Nodes_Assignment(o, collector) case o.right - when Arel::Nodes::UnqualifiedColumn, Arel::Attributes::Attribute, Arel::Nodes::BindParam + when Arel::Nodes::Node, Arel::Attributes::Attribute collector = visit o.left, collector collector << " = " visit o.right, collector @@ -739,8 +714,6 @@ module Arel # :nodoc: all end alias :visit_Arel_Nodes_SqlLiteral :literal - alias :visit_Bignum :literal - alias :visit_Fixnum :literal alias :visit_Integer :literal def quoted(o, a) @@ -823,6 +796,49 @@ module Arel # :nodoc: all } end + def boundable?(value) + !value.respond_to?(:boundable?) || value.boundable? + end + + def has_join_sources?(o) + o.relation.is_a?(Nodes::JoinSource) && !o.relation.right.empty? + end + + def has_limit_or_offset_or_orders?(o) + o.limit || o.offset || !o.orders.empty? + end + + # The default strategy for an UPDATE with joins is to use a subquery. This doesn't work + # on MySQL (even when aliasing the tables), but MySQL allows using JOIN directly in + # an UPDATE statement, so in the MySQL visitor we redefine this to do that. + def prepare_update_statement(o) + if o.key && (has_limit_or_offset_or_orders?(o) || has_join_sources?(o)) + stmt = o.clone + stmt.limit = nil + stmt.offset = nil + stmt.orders = [] + stmt.wheres = [Nodes::In.new(o.key, [build_subselect(o.key, o)])] + stmt.relation = o.relation.left if has_join_sources?(o) + stmt + else + o + end + end + alias :prepare_delete_statement :prepare_update_statement + + # FIXME: we should probably have a 2-pass visitor for this + def build_subselect(key, o) + stmt = Nodes::SelectStatement.new + core = stmt.cores.first + core.froms = o.relation + core.wheres = o.wheres + core.projections = [key] + stmt.limit = o.limit + stmt.offset = o.offset + stmt.orders = o.orders + stmt + end + def infix_value(o, collector, value) collector = visit o.left, collector collector << value |