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-rw-r--r--activerecord/lib/arel/visitors/depth_first.rb199
-rw-r--r--activerecord/lib/arel/visitors/dot.rb291
-rw-r--r--activerecord/lib/arel/visitors/ibm_db.rb15
-rw-r--r--activerecord/lib/arel/visitors/informix.rb55
-rw-r--r--activerecord/lib/arel/visitors/mssql.rb124
-rw-r--r--activerecord/lib/arel/visitors/mysql.rb86
-rw-r--r--activerecord/lib/arel/visitors/oracle.rb153
-rw-r--r--activerecord/lib/arel/visitors/oracle12.rb60
-rw-r--r--activerecord/lib/arel/visitors/postgresql.rb103
-rw-r--r--activerecord/lib/arel/visitors/sqlite.rb27
-rw-r--r--activerecord/lib/arel/visitors/to_sql.rb846
-rw-r--r--activerecord/lib/arel/visitors/visitor.rb41
-rw-r--r--activerecord/lib/arel/visitors/where_sql.rb22
13 files changed, 2022 insertions, 0 deletions
diff --git a/activerecord/lib/arel/visitors/depth_first.rb b/activerecord/lib/arel/visitors/depth_first.rb
new file mode 100644
index 0000000000..b3bbc9bd40
--- /dev/null
+++ b/activerecord/lib/arel/visitors/depth_first.rb
@@ -0,0 +1,199 @@
+# frozen_string_literal: true
+module Arel
+ module Visitors
+ class DepthFirst < Arel::Visitors::Visitor
+ def initialize block = nil
+ @block = block || Proc.new
+ super()
+ end
+
+ private
+
+ def visit o
+ super
+ @block.call o
+ end
+
+ def unary o
+ visit o.expr
+ end
+ alias :visit_Arel_Nodes_Else :unary
+ alias :visit_Arel_Nodes_Group :unary
+ alias :visit_Arel_Nodes_Cube :unary
+ alias :visit_Arel_Nodes_RollUp :unary
+ alias :visit_Arel_Nodes_GroupingSet :unary
+ alias :visit_Arel_Nodes_GroupingElement :unary
+ alias :visit_Arel_Nodes_Grouping :unary
+ alias :visit_Arel_Nodes_Having :unary
+ alias :visit_Arel_Nodes_Lateral :unary
+ alias :visit_Arel_Nodes_Limit :unary
+ alias :visit_Arel_Nodes_Not :unary
+ alias :visit_Arel_Nodes_Offset :unary
+ alias :visit_Arel_Nodes_On :unary
+ 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
+ visit o.expressions
+ visit o.alias
+ visit o.distinct
+ end
+ alias :visit_Arel_Nodes_Avg :function
+ alias :visit_Arel_Nodes_Exists :function
+ alias :visit_Arel_Nodes_Max :function
+ alias :visit_Arel_Nodes_Min :function
+ alias :visit_Arel_Nodes_Sum :function
+
+ def visit_Arel_Nodes_NamedFunction o
+ visit o.name
+ visit o.expressions
+ visit o.distinct
+ visit o.alias
+ end
+
+ def visit_Arel_Nodes_Count o
+ visit o.expressions
+ visit o.alias
+ visit o.distinct
+ end
+
+ def visit_Arel_Nodes_Case o
+ visit o.case
+ visit o.conditions
+ visit o.default
+ end
+
+ def nary o
+ o.children.each { |child| visit child}
+ end
+ alias :visit_Arel_Nodes_And :nary
+
+ def binary o
+ visit o.left
+ visit o.right
+ end
+ alias :visit_Arel_Nodes_As :binary
+ alias :visit_Arel_Nodes_Assignment :binary
+ alias :visit_Arel_Nodes_Between :binary
+ alias :visit_Arel_Nodes_Concat :binary
+ alias :visit_Arel_Nodes_DeleteStatement :binary
+ alias :visit_Arel_Nodes_DoesNotMatch :binary
+ alias :visit_Arel_Nodes_Equality :binary
+ alias :visit_Arel_Nodes_FullOuterJoin :binary
+ alias :visit_Arel_Nodes_GreaterThan :binary
+ alias :visit_Arel_Nodes_GreaterThanOrEqual :binary
+ alias :visit_Arel_Nodes_In :binary
+ alias :visit_Arel_Nodes_InfixOperation :binary
+ alias :visit_Arel_Nodes_JoinSource :binary
+ alias :visit_Arel_Nodes_InnerJoin :binary
+ alias :visit_Arel_Nodes_LessThan :binary
+ alias :visit_Arel_Nodes_LessThanOrEqual :binary
+ alias :visit_Arel_Nodes_Matches :binary
+ alias :visit_Arel_Nodes_NotEqual :binary
+ alias :visit_Arel_Nodes_NotIn :binary
+ alias :visit_Arel_Nodes_NotRegexp :binary
+ alias :visit_Arel_Nodes_Or :binary
+ alias :visit_Arel_Nodes_OuterJoin :binary
+ alias :visit_Arel_Nodes_Regexp :binary
+ alias :visit_Arel_Nodes_RightOuterJoin :binary
+ alias :visit_Arel_Nodes_TableAlias :binary
+ alias :visit_Arel_Nodes_Values :binary
+ alias :visit_Arel_Nodes_When :binary
+
+ def visit_Arel_Nodes_StringJoin o
+ visit o.left
+ end
+
+ def visit_Arel_Attribute o
+ visit o.relation
+ visit o.name
+ end
+ alias :visit_Arel_Attributes_Integer :visit_Arel_Attribute
+ alias :visit_Arel_Attributes_Float :visit_Arel_Attribute
+ alias :visit_Arel_Attributes_String :visit_Arel_Attribute
+ alias :visit_Arel_Attributes_Time :visit_Arel_Attribute
+ alias :visit_Arel_Attributes_Boolean :visit_Arel_Attribute
+ alias :visit_Arel_Attributes_Attribute :visit_Arel_Attribute
+ alias :visit_Arel_Attributes_Decimal :visit_Arel_Attribute
+
+ def visit_Arel_Table o
+ visit o.name
+ end
+
+ def terminal o
+ end
+ alias :visit_ActiveSupport_Multibyte_Chars :terminal
+ alias :visit_ActiveSupport_StringInquirer :terminal
+ alias :visit_Arel_Nodes_Lock :terminal
+ alias :visit_Arel_Nodes_Node :terminal
+ alias :visit_Arel_Nodes_SqlLiteral :terminal
+ alias :visit_Arel_Nodes_BindParam :terminal
+ alias :visit_Arel_Nodes_Window :terminal
+ 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
+ alias :visit_String :terminal
+ alias :visit_Symbol :terminal
+ alias :visit_Time :terminal
+ alias :visit_TrueClass :terminal
+
+ def visit_Arel_Nodes_InsertStatement o
+ visit o.relation
+ visit o.columns
+ visit o.values
+ end
+
+ def visit_Arel_Nodes_SelectCore o
+ visit o.projections
+ visit o.source
+ visit o.wheres
+ visit o.groups
+ visit o.windows
+ visit o.havings
+ end
+
+ def visit_Arel_Nodes_SelectStatement o
+ visit o.cores
+ visit o.orders
+ visit o.limit
+ visit o.lock
+ visit o.offset
+ end
+
+ def visit_Arel_Nodes_UpdateStatement o
+ visit o.relation
+ visit o.values
+ visit o.wheres
+ visit o.orders
+ visit o.limit
+ end
+
+ def visit_Array o
+ o.each { |i| visit i }
+ end
+ alias :visit_Set :visit_Array
+
+ def visit_Hash o
+ o.each { |k,v| visit(k); visit(v) }
+ end
+
+ DISPATCH = dispatch_cache
+
+ def get_dispatch_cache
+ DISPATCH
+ end
+ end
+ end
+end
diff --git a/activerecord/lib/arel/visitors/dot.rb b/activerecord/lib/arel/visitors/dot.rb
new file mode 100644
index 0000000000..9aa22d33f6
--- /dev/null
+++ b/activerecord/lib/arel/visitors/dot.rb
@@ -0,0 +1,291 @@
+# frozen_string_literal: true
+module Arel
+ module Visitors
+ class Dot < Arel::Visitors::Visitor
+ class Node # :nodoc:
+ attr_accessor :name, :id, :fields
+
+ def initialize name, id, fields = []
+ @name = name
+ @id = id
+ @fields = fields
+ end
+ end
+
+ class Edge < Struct.new :name, :from, :to # :nodoc:
+ end
+
+ def initialize
+ super()
+ @nodes = []
+ @edges = []
+ @node_stack = []
+ @edge_stack = []
+ @seen = {}
+ end
+
+ def accept object, collector
+ visit object
+ collector << to_dot
+ end
+
+ private
+
+ def visit_Arel_Nodes_Ordering o
+ visit_edge o, "expr"
+ end
+
+ def visit_Arel_Nodes_TableAlias o
+ visit_edge o, "name"
+ visit_edge o, "relation"
+ end
+
+ def visit_Arel_Nodes_Count o
+ visit_edge o, "expressions"
+ visit_edge o, "distinct"
+ end
+
+ def visit_Arel_Nodes_Values o
+ visit_edge o, "expressions"
+ end
+
+ def visit_Arel_Nodes_StringJoin o
+ visit_edge o, "left"
+ end
+
+ def visit_Arel_Nodes_InnerJoin o
+ visit_edge o, "left"
+ visit_edge o, "right"
+ end
+ alias :visit_Arel_Nodes_FullOuterJoin :visit_Arel_Nodes_InnerJoin
+ alias :visit_Arel_Nodes_OuterJoin :visit_Arel_Nodes_InnerJoin
+ alias :visit_Arel_Nodes_RightOuterJoin :visit_Arel_Nodes_InnerJoin
+
+ def visit_Arel_Nodes_DeleteStatement o
+ visit_edge o, "relation"
+ visit_edge o, "wheres"
+ end
+
+ def unary o
+ visit_edge o, "expr"
+ end
+ alias :visit_Arel_Nodes_Group :unary
+ alias :visit_Arel_Nodes_Cube :unary
+ alias :visit_Arel_Nodes_RollUp :unary
+ alias :visit_Arel_Nodes_GroupingSet :unary
+ alias :visit_Arel_Nodes_GroupingElement :unary
+ alias :visit_Arel_Nodes_Grouping :unary
+ alias :visit_Arel_Nodes_Having :unary
+ alias :visit_Arel_Nodes_Limit :unary
+ 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
+ alias :visit_Arel_Nodes_Rows :unary
+ alias :visit_Arel_Nodes_Range :unary
+
+ def window o
+ visit_edge o, "partitions"
+ visit_edge o, "orders"
+ visit_edge o, "framing"
+ end
+ alias :visit_Arel_Nodes_Window :window
+
+ def named_window o
+ visit_edge o, "partitions"
+ visit_edge o, "orders"
+ visit_edge o, "framing"
+ visit_edge o, "name"
+ end
+ alias :visit_Arel_Nodes_NamedWindow :named_window
+
+ def function o
+ visit_edge o, "expressions"
+ visit_edge o, "distinct"
+ visit_edge o, "alias"
+ end
+ alias :visit_Arel_Nodes_Exists :function
+ alias :visit_Arel_Nodes_Min :function
+ alias :visit_Arel_Nodes_Max :function
+ alias :visit_Arel_Nodes_Avg :function
+ alias :visit_Arel_Nodes_Sum :function
+
+ def extract o
+ visit_edge o, "expressions"
+ visit_edge o, "alias"
+ end
+ alias :visit_Arel_Nodes_Extract :extract
+
+ def visit_Arel_Nodes_NamedFunction o
+ visit_edge o, "name"
+ visit_edge o, "expressions"
+ visit_edge o, "distinct"
+ visit_edge o, "alias"
+ end
+
+ def visit_Arel_Nodes_InsertStatement o
+ visit_edge o, "relation"
+ visit_edge o, "columns"
+ visit_edge o, "values"
+ end
+
+ def visit_Arel_Nodes_SelectCore o
+ visit_edge o, "source"
+ visit_edge o, "projections"
+ visit_edge o, "wheres"
+ visit_edge o, "windows"
+ end
+
+ def visit_Arel_Nodes_SelectStatement o
+ visit_edge o, "cores"
+ visit_edge o, "limit"
+ visit_edge o, "orders"
+ visit_edge o, "offset"
+ end
+
+ def visit_Arel_Nodes_UpdateStatement o
+ visit_edge o, "relation"
+ visit_edge o, "wheres"
+ visit_edge o, "values"
+ end
+
+ def visit_Arel_Table o
+ visit_edge o, "name"
+ end
+
+ def visit_Arel_Nodes_Casted o
+ visit_edge o, 'val'
+ visit_edge o, 'attribute'
+ end
+
+ def visit_Arel_Attribute o
+ visit_edge o, "relation"
+ visit_edge o, "name"
+ end
+ alias :visit_Arel_Attributes_Integer :visit_Arel_Attribute
+ alias :visit_Arel_Attributes_Float :visit_Arel_Attribute
+ alias :visit_Arel_Attributes_String :visit_Arel_Attribute
+ alias :visit_Arel_Attributes_Time :visit_Arel_Attribute
+ alias :visit_Arel_Attributes_Boolean :visit_Arel_Attribute
+ alias :visit_Arel_Attributes_Attribute :visit_Arel_Attribute
+
+ def nary o
+ o.children.each_with_index do |x,i|
+ edge(i) { visit x }
+ end
+ end
+ alias :visit_Arel_Nodes_And :nary
+
+ def binary o
+ visit_edge o, "left"
+ visit_edge o, "right"
+ end
+ alias :visit_Arel_Nodes_As :binary
+ alias :visit_Arel_Nodes_Assignment :binary
+ alias :visit_Arel_Nodes_Between :binary
+ alias :visit_Arel_Nodes_Concat :binary
+ alias :visit_Arel_Nodes_DoesNotMatch :binary
+ alias :visit_Arel_Nodes_Equality :binary
+ alias :visit_Arel_Nodes_GreaterThan :binary
+ alias :visit_Arel_Nodes_GreaterThanOrEqual :binary
+ alias :visit_Arel_Nodes_In :binary
+ alias :visit_Arel_Nodes_JoinSource :binary
+ alias :visit_Arel_Nodes_LessThan :binary
+ alias :visit_Arel_Nodes_LessThanOrEqual :binary
+ alias :visit_Arel_Nodes_Matches :binary
+ alias :visit_Arel_Nodes_NotEqual :binary
+ alias :visit_Arel_Nodes_NotIn :binary
+ alias :visit_Arel_Nodes_Or :binary
+ alias :visit_Arel_Nodes_Over :binary
+
+ def visit_String o
+ @node_stack.last.fields << o
+ end
+ alias :visit_Time :visit_String
+ alias :visit_Date :visit_String
+ alias :visit_DateTime :visit_String
+ alias :visit_NilClass :visit_String
+ 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
+ alias :visit_Arel_Nodes_SqlLiteral :visit_String
+
+ def visit_Arel_Nodes_BindParam o; end
+
+ def visit_Hash o
+ o.each_with_index do |pair, i|
+ edge("pair_#{i}") { visit pair }
+ end
+ end
+
+ def visit_Array o
+ o.each_with_index do |x,i|
+ edge(i) { visit x }
+ end
+ end
+ alias :visit_Set :visit_Array
+
+ def visit_edge o, method
+ edge(method) { visit o.send(method) }
+ end
+
+ def visit o
+ if node = @seen[o.object_id]
+ @edge_stack.last.to = node
+ return
+ end
+
+ node = Node.new(o.class.name, o.object_id)
+ @seen[node.id] = node
+ @nodes << node
+ with_node node do
+ super
+ end
+ end
+
+ def edge name
+ edge = Edge.new(name, @node_stack.last)
+ @edge_stack.push edge
+ @edges << edge
+ yield
+ @edge_stack.pop
+ end
+
+ def with_node node
+ if edge = @edge_stack.last
+ edge.to = node
+ end
+
+ @node_stack.push node
+ yield
+ @node_stack.pop
+ end
+
+ def quote string
+ string.to_s.gsub('"', '\"')
+ end
+
+ def to_dot
+ "digraph \"Arel\" {\nnode [width=0.375,height=0.25,shape=record];\n" +
+ @nodes.map { |node|
+ label = "<f0>#{node.name}"
+
+ node.fields.each_with_index do |field, i|
+ label += "|<f#{i + 1}>#{quote field}"
+ end
+
+ "#{node.id} [label=\"#{label}\"];"
+ }.join("\n") + "\n" + @edges.map { |edge|
+ "#{edge.from.id} -> #{edge.to.id} [label=\"#{edge.name}\"];"
+ }.join("\n") + "\n}"
+ end
+ end
+ end
+end
diff --git a/activerecord/lib/arel/visitors/ibm_db.rb b/activerecord/lib/arel/visitors/ibm_db.rb
new file mode 100644
index 0000000000..e85a5a08a7
--- /dev/null
+++ b/activerecord/lib/arel/visitors/ibm_db.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+module Arel
+ module Visitors
+ class IBM_DB < Arel::Visitors::ToSql
+ private
+
+ def visit_Arel_Nodes_Limit o, collector
+ collector << "FETCH FIRST "
+ collector = visit o.expr, collector
+ collector << " ROWS ONLY"
+ end
+
+ end
+ end
+end
diff --git a/activerecord/lib/arel/visitors/informix.rb b/activerecord/lib/arel/visitors/informix.rb
new file mode 100644
index 0000000000..44b18b550e
--- /dev/null
+++ b/activerecord/lib/arel/visitors/informix.rb
@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+module Arel
+ module Visitors
+ class Informix < Arel::Visitors::ToSql
+ private
+ def visit_Arel_Nodes_SelectStatement o, collector
+ collector << "SELECT "
+ collector = maybe_visit o.offset, collector
+ collector = maybe_visit o.limit, collector
+ collector = o.cores.inject(collector) { |c,x|
+ visit_Arel_Nodes_SelectCore x, c
+ }
+ if o.orders.any?
+ collector << "ORDER BY "
+ collector = inject_join o.orders, collector, ", "
+ end
+ collector = maybe_visit o.lock, collector
+ end
+ def visit_Arel_Nodes_SelectCore o, collector
+ collector = inject_join o.projections, collector, ", "
+ if o.source && !o.source.empty?
+ collector << " FROM "
+ collector = visit o.source, collector
+ end
+
+ if o.wheres.any?
+ collector << " WHERE "
+ collector = inject_join o.wheres, collector, " AND "
+ end
+
+ if o.groups.any?
+ collector << "GROUP BY "
+ collector = inject_join o.groups, collector, ", "
+ end
+
+ if o.havings.any?
+ collector << " HAVING "
+ collector = inject_join o.havings, collector, " AND "
+ end
+ collector
+ end
+
+ def visit_Arel_Nodes_Offset o, collector
+ collector << "SKIP "
+ visit o.expr, collector
+ end
+ def visit_Arel_Nodes_Limit o, collector
+ collector << "FIRST "
+ visit o.expr, collector
+ collector << " "
+ end
+ end
+ end
+end
+
diff --git a/activerecord/lib/arel/visitors/mssql.rb b/activerecord/lib/arel/visitors/mssql.rb
new file mode 100644
index 0000000000..8347d05d06
--- /dev/null
+++ b/activerecord/lib/arel/visitors/mssql.rb
@@ -0,0 +1,124 @@
+# frozen_string_literal: true
+module Arel
+ module Visitors
+ class MSSQL < Arel::Visitors::ToSql
+ RowNumber = Struct.new :children
+
+ def initialize(*)
+ @primary_keys = {}
+ super
+ end
+
+ 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"
+ end
+
+ def visit_Arel_Nodes_SelectStatement o, collector
+ if !o.limit && !o.offset
+ return super
+ end
+
+ is_select_count = false
+ o.cores.each { |x|
+ core_order_by = row_num_literal determine_order_by(o.orders, x)
+ if select_count? x
+ x.projections = [core_order_by]
+ is_select_count = true
+ else
+ x.projections << core_order_by
+ end
+ }
+
+ if is_select_count
+ # fixme count distinct wouldn't work with limit or offset
+ collector << "SELECT COUNT(1) as count_id FROM ("
+ end
+
+ collector << "SELECT _t.* FROM ("
+ collector = o.cores.inject(collector) { |c,x|
+ visit_Arel_Nodes_SelectCore x, c
+ }
+ collector << ") as _t WHERE #{get_offset_limit_clause(o)}"
+
+ if is_select_count
+ collector << ") AS subquery"
+ else
+ collector
+ end
+ end
+
+ def get_offset_limit_clause o
+ first_row = o.offset ? o.offset.expr.to_i + 1 : 1
+ last_row = o.limit ? o.limit.expr.to_i - 1 + first_row : nil
+ if last_row
+ " _row_num BETWEEN #{first_row} AND #{last_row}"
+ else
+ " _row_num >= #{first_row}"
+ end
+ end
+
+ def visit_Arel_Nodes_DeleteStatement o, collector
+ collector << 'DELETE '
+ if o.limit
+ collector << 'TOP ('
+ visit o.limit.expr, collector
+ collector << ') '
+ end
+ collector << 'FROM '
+ collector = visit o.relation, collector
+ if o.wheres.any?
+ collector << ' WHERE '
+ inject_join o.wheres, collector, AND
+ else
+ collector
+ end
+ end
+
+ def determine_order_by orders, x
+ if orders.any?
+ orders
+ elsif x.groups.any?
+ x.groups
+ else
+ pk = find_left_table_pk(x.froms)
+ pk ? [pk] : []
+ end
+ end
+
+ def row_num_literal order_by
+ RowNumber.new order_by
+ end
+
+ def select_count? x
+ x.projections.length == 1 && Arel::Nodes::Count === x.projections.first
+ end
+
+ # FIXME raise exception of there is no pk?
+ def find_left_table_pk o
+ if o.kind_of?(Arel::Nodes::Join)
+ find_left_table_pk(o.left)
+ elsif o.instance_of?(Arel::Table)
+ find_primary_key(o)
+ end
+ end
+
+ def find_primary_key(o)
+ @primary_keys[o.name] ||= begin
+ primary_key_name = @connection.primary_key(o.name)
+ # some tables might be without primary key
+ primary_key_name && o[primary_key_name]
+ end
+ end
+ end
+ end
+end
diff --git a/activerecord/lib/arel/visitors/mysql.rb b/activerecord/lib/arel/visitors/mysql.rb
new file mode 100644
index 0000000000..4c734f6292
--- /dev/null
+++ b/activerecord/lib/arel/visitors/mysql.rb
@@ -0,0 +1,86 @@
+# frozen_string_literal: true
+module Arel
+ module Visitors
+ class MySQL < Arel::Visitors::ToSql
+ private
+ def visit_Arel_Nodes_Union o, collector, suppress_parens = false
+ unless suppress_parens
+ collector << "( "
+ end
+
+ 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
+ end
+
+ if suppress_parens
+ collector
+ else
+ collector << " )"
+ end
+ end
+
+ def visit_Arel_Nodes_Bin o, collector
+ collector << "BINARY "
+ visit o.expr, collector
+ end
+
+ ###
+ # :'(
+ # http://dev.mysql.com/doc/refman/5.0/en/select.html#id3482214
+ def visit_Arel_Nodes_SelectStatement o, collector
+ if o.offset && !o.limit
+ o.limit = Arel::Nodes::Limit.new(18446744073709551615)
+ end
+ super
+ end
+
+ def visit_Arel_Nodes_SelectCore o, collector
+ o.froms ||= Arel.sql('DUAL')
+ 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
+ collector << ", "
+ visit o.right, collector
+ collector << ") "
+ collector
+ end
+ end
+ end
+end
diff --git a/activerecord/lib/arel/visitors/oracle.rb b/activerecord/lib/arel/visitors/oracle.rb
new file mode 100644
index 0000000000..d4749bbae3
--- /dev/null
+++ b/activerecord/lib/arel/visitors/oracle.rb
@@ -0,0 +1,153 @@
+# frozen_string_literal: true
+module Arel
+ module Visitors
+ class Oracle < Arel::Visitors::ToSql
+ private
+
+ def visit_Arel_Nodes_SelectStatement o, collector
+ o = order_hacks(o)
+
+ # if need to select first records without ORDER BY and GROUP BY and without DISTINCT
+ # then can use simple ROWNUM in WHERE clause
+ if o.limit && o.orders.empty? && o.cores.first.groups.empty? && !o.offset && o.cores.first.set_quantifier.class.to_s !~ /Distinct/
+ o.cores.last.wheres.push Nodes::LessThanOrEqual.new(
+ Nodes::SqlLiteral.new('ROWNUM'), o.limit.expr
+ )
+ return super
+ end
+
+ if o.limit && o.offset
+ o = o.dup
+ limit = o.limit.expr
+ offset = o.offset
+ o.offset = nil
+ collector << "
+ SELECT * FROM (
+ SELECT raw_sql_.*, rownum raw_rnum_
+ FROM ("
+
+ collector = super(o, collector)
+
+ if offset.expr.is_a? Nodes::BindParam
+ collector << ') raw_sql_ WHERE rownum <= ('
+ collector = visit offset.expr, collector
+ collector << ' + '
+ collector = visit limit, collector
+ collector << ") ) WHERE raw_rnum_ > "
+ collector = visit offset.expr, collector
+ return collector
+ else
+ collector << ") raw_sql_
+ WHERE rownum <= #{offset.expr.to_i + limit}
+ )
+ WHERE "
+ return visit(offset, collector)
+ end
+ end
+
+ if o.limit
+ o = o.dup
+ limit = o.limit.expr
+ collector << "SELECT * FROM ("
+ collector = super(o, collector)
+ collector << ") WHERE ROWNUM <= "
+ return visit limit, collector
+ end
+
+ if o.offset
+ o = o.dup
+ offset = o.offset
+ o.offset = nil
+ collector << "SELECT * FROM (
+ SELECT raw_sql_.*, rownum raw_rnum_
+ FROM ("
+ collector = super(o, collector)
+ collector << ") raw_sql_
+ )
+ WHERE "
+ return visit offset, collector
+ end
+
+ super
+ end
+
+ def visit_Arel_Nodes_Limit o, collector
+ collector
+ end
+
+ def visit_Arel_Nodes_Offset o, collector
+ collector << "raw_rnum_ > "
+ visit o.expr, collector
+ end
+
+ def visit_Arel_Nodes_Except o, collector
+ collector << "( "
+ collector = infix_value o, collector, " MINUS "
+ collector << " )"
+ end
+
+ def visit_Arel_Nodes_UpdateStatement o, collector
+ # Oracle does not allow ORDER BY/LIMIT in UPDATEs.
+ if o.orders.any? && o.limit.nil?
+ # However, there is no harm in silently eating the ORDER BY clause if no LIMIT has been provided,
+ # otherwise let the user deal with the error
+ o = o.dup
+ o.orders = []
+ end
+
+ super
+ end
+
+ ###
+ # Hacks for the order clauses specific to Oracle
+ def order_hacks o
+ return o if o.orders.empty?
+ return o unless o.cores.any? do |core|
+ core.projections.any? do |projection|
+ /FIRST_VALUE/ === projection
+ end
+ end
+ # Previous version with join and split broke ORDER BY clause
+ # if it contained functions with several arguments (separated by ',').
+ #
+ # orders = o.orders.map { |x| visit x }.join(', ').split(',')
+ orders = o.orders.map do |x|
+ string = visit(x, Arel::Collectors::SQLString.new).value
+ if string.include?(',')
+ split_order_string(string)
+ else
+ string
+ end
+ end.flatten
+ o.orders = []
+ orders.each_with_index do |order, i|
+ o.orders <<
+ Nodes::SqlLiteral.new("alias_#{i}__#{' DESC' if /\bdesc$/i === order}")
+ end
+ o
+ end
+
+ # Split string by commas but count opening and closing brackets
+ # and ignore commas inside brackets.
+ def split_order_string(string)
+ array = []
+ i = 0
+ string.split(',').each do |part|
+ if array[i]
+ array[i] << ',' << part
+ else
+ # to ensure that array[i] will be String and not Arel::Nodes::SqlLiteral
+ array[i] = part.to_s
+ end
+ i += 1 if array[i].count('(') == array[i].count(')')
+ end
+ array
+ end
+
+ def visit_Arel_Nodes_BindParam o, collector
+ collector.add_bind(o.value) { |i| ":a#{i}" }
+ end
+
+ end
+ end
+end
diff --git a/activerecord/lib/arel/visitors/oracle12.rb b/activerecord/lib/arel/visitors/oracle12.rb
new file mode 100644
index 0000000000..648047ae61
--- /dev/null
+++ b/activerecord/lib/arel/visitors/oracle12.rb
@@ -0,0 +1,60 @@
+# frozen_string_literal: true
+module Arel
+ module Visitors
+ class Oracle12 < Arel::Visitors::ToSql
+ private
+
+ def visit_Arel_Nodes_SelectStatement o, collector
+ # Oracle does not allow LIMIT clause with select for update
+ if o.limit && o.lock
+ raise ArgumentError, <<-MSG
+ 'Combination of limit and lock is not supported.
+ because generated SQL statements
+ `SELECT FOR UPDATE and FETCH FIRST n ROWS` generates ORA-02014.`
+ MSG
+ end
+ super
+ end
+
+ def visit_Arel_Nodes_SelectOptions o, collector
+ collector = maybe_visit o.offset, collector
+ collector = maybe_visit o.limit, collector
+ collector = maybe_visit o.lock, collector
+ end
+
+ def visit_Arel_Nodes_Limit o, collector
+ collector << "FETCH FIRST "
+ collector = visit o.expr, collector
+ collector << " ROWS ONLY"
+ end
+
+ def visit_Arel_Nodes_Offset o, collector
+ collector << "OFFSET "
+ visit o.expr, collector
+ collector << " ROWS"
+ end
+
+ def visit_Arel_Nodes_Except o, collector
+ collector << "( "
+ collector = infix_value o, collector, " MINUS "
+ collector << " )"
+ end
+
+ def visit_Arel_Nodes_UpdateStatement o, collector
+ # Oracle does not allow ORDER BY/LIMIT in UPDATEs.
+ if o.orders.any? && o.limit.nil?
+ # However, there is no harm in silently eating the ORDER BY clause if no LIMIT has been provided,
+ # otherwise let the user deal with the error
+ o = o.dup
+ o.orders = []
+ end
+
+ super
+ end
+
+ def visit_Arel_Nodes_BindParam o, collector
+ collector.add_bind(o.value) { |i| ":a#{i}" }
+ end
+ end
+ end
+end
diff --git a/activerecord/lib/arel/visitors/postgresql.rb b/activerecord/lib/arel/visitors/postgresql.rb
new file mode 100644
index 0000000000..047f71aaa6
--- /dev/null
+++ b/activerecord/lib/arel/visitors/postgresql.rb
@@ -0,0 +1,103 @@
+# frozen_string_literal: true
+module Arel
+ module Visitors
+ class PostgreSQL < Arel::Visitors::ToSql
+ CUBE = 'CUBE'
+ ROLLUP = 'ROLLUP'
+ GROUPING_SET = 'GROUPING SET'
+ LATERAL = 'LATERAL'
+
+ private
+
+ def visit_Arel_Nodes_Matches o, collector
+ op = o.case_sensitive ? ' LIKE ' : ' ILIKE '
+ collector = infix_value o, collector, op
+ if o.escape
+ collector << ' ESCAPE '
+ visit o.escape, collector
+ else
+ collector
+ end
+ end
+
+ def visit_Arel_Nodes_DoesNotMatch o, collector
+ op = o.case_sensitive ? ' NOT LIKE ' : ' NOT ILIKE '
+ collector = infix_value o, collector, op
+ if o.escape
+ collector << ' ESCAPE '
+ visit o.escape, collector
+ else
+ collector
+ end
+ end
+
+ def visit_Arel_Nodes_Regexp o, collector
+ op = o.case_sensitive ? ' ~ ' : ' ~* '
+ infix_value o, collector, op
+ end
+
+ def visit_Arel_Nodes_NotRegexp o, collector
+ op = o.case_sensitive ? ' !~ ' : ' !~* '
+ infix_value o, collector, op
+ end
+
+ def visit_Arel_Nodes_DistinctOn o, collector
+ collector << "DISTINCT ON ( "
+ visit(o.expr, collector) << " )"
+ end
+
+ def visit_Arel_Nodes_BindParam o, collector
+ collector.add_bind(o.value) { |i| "$#{i}" }
+ end
+
+ def visit_Arel_Nodes_GroupingElement o, collector
+ collector << "( "
+ visit(o.expr, collector) << " )"
+ end
+
+ def visit_Arel_Nodes_Cube o, collector
+ collector << CUBE
+ grouping_array_or_grouping_element o, collector
+ end
+
+ def visit_Arel_Nodes_RollUp o, collector
+ collector << ROLLUP
+ grouping_array_or_grouping_element o, collector
+ end
+
+ def visit_Arel_Nodes_GroupingSet o, collector
+ collector << GROUPING_SET
+ grouping_array_or_grouping_element o, collector
+ end
+
+ def visit_Arel_Nodes_Lateral o, collector
+ collector << LATERAL
+ collector << SPACE
+ grouping_parentheses o, collector
+ end
+
+ # Used by Lateral visitor to enclose select queries in parentheses
+ def grouping_parentheses o, collector
+ if o.expr.is_a? Nodes::SelectStatement
+ collector << "("
+ visit o.expr, collector
+ collector << ")"
+ else
+ visit o.expr, collector
+ end
+ end
+
+ # Utilized by GroupingSet, Cube & RollUp visitors to
+ # handle grouping aggregation semantics
+ def grouping_array_or_grouping_element o, collector
+ if o.expr.is_a? Array
+ collector << "( "
+ visit o.expr, collector
+ collector << " )"
+ else
+ visit o.expr, collector
+ end
+ end
+ end
+ end
+end
diff --git a/activerecord/lib/arel/visitors/sqlite.rb b/activerecord/lib/arel/visitors/sqlite.rb
new file mode 100644
index 0000000000..4ae093968b
--- /dev/null
+++ b/activerecord/lib/arel/visitors/sqlite.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+module Arel
+ module Visitors
+ class SQLite < Arel::Visitors::ToSql
+ private
+
+ # Locks are not supported in SQLite
+ def visit_Arel_Nodes_Lock o, collector
+ collector
+ end
+
+ def visit_Arel_Nodes_SelectStatement o, collector
+ o.limit = Arel::Nodes::Limit.new(-1) if o.offset && !o.limit
+ super
+ end
+
+ def visit_Arel_Nodes_True o, collector
+ collector << "1"
+ end
+
+ def visit_Arel_Nodes_False o, collector
+ collector << "0"
+ end
+
+ end
+ end
+end
diff --git a/activerecord/lib/arel/visitors/to_sql.rb b/activerecord/lib/arel/visitors/to_sql.rb
new file mode 100644
index 0000000000..2b5c43b173
--- /dev/null
+++ b/activerecord/lib/arel/visitors/to_sql.rb
@@ -0,0 +1,846 @@
+# frozen_string_literal: true
+module Arel
+ module Visitors
+ class UnsupportedVisitError < StandardError
+ def initialize(object)
+ super "Unsupported argument type: #{object.class.name}. Construct an Arel node instead."
+ end
+ end
+
+ class ToSql < Arel::Visitors::Visitor
+ ##
+ # This is some roflscale crazy stuff. I'm roflscaling this because
+ # building SQL queries is a hotspot. I will explain the roflscale so that
+ # others will not rm this code.
+ #
+ # In YARV, string literals in a method body will get duped when the byte
+ # code is executed. Let's take a look:
+ #
+ # > puts RubyVM::InstructionSequence.new('def foo; "bar"; end').disasm
+ #
+ # == disasm: <RubyVM::InstructionSequence:foo@<compiled>>=====
+ # 0000 trace 8
+ # 0002 trace 1
+ # 0004 putstring "bar"
+ # 0006 trace 16
+ # 0008 leave
+ #
+ # The `putstring` bytecode will dup the string and push it on the stack.
+ # In many cases in our SQL visitor, that string is never mutated, so there
+ # is no need to dup the literal.
+ #
+ # If we change to a constant lookup, the string will not be duped, and we
+ # can reduce the objects in our system:
+ #
+ # > puts RubyVM::InstructionSequence.new('BAR = "bar"; def foo; BAR; end').disasm
+ #
+ # == disasm: <RubyVM::InstructionSequence:foo@<compiled>>========
+ # 0000 trace 8
+ # 0002 trace 1
+ # 0004 getinlinecache 11, <ic:0>
+ # 0007 getconstant :BAR
+ # 0009 setinlinecache <ic:0>
+ # 0011 trace 16
+ # 0013 leave
+ #
+ # `getconstant` should be a hash lookup, and no object is duped when the
+ # value of the constant is pushed on the stack. Hence the crazy
+ # constants below.
+ #
+ # `matches` and `doesNotMatch` operate case-insensitively via Visitor subclasses
+ # specialized for specific databases when necessary.
+ #
+
+ WHERE = ' WHERE ' # :nodoc:
+ SPACE = ' ' # :nodoc:
+ COMMA = ', ' # :nodoc:
+ GROUP_BY = ' GROUP BY ' # :nodoc:
+ ORDER_BY = ' ORDER BY ' # :nodoc:
+ WINDOW = ' WINDOW ' # :nodoc:
+ AND = ' AND ' # :nodoc:
+
+ DISTINCT = 'DISTINCT' # :nodoc:
+
+ def initialize connection
+ super()
+ @connection = connection
+ end
+
+ def compile node, &block
+ accept(node, Arel::Collectors::SQLString.new, &block).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
+ end
+
+ 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
+
+ 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
+
+ collector
+ end
+
+ def visit_Arel_Nodes_InsertStatement o, collector
+ collector << "INSERT INTO "
+ collector = visit o.relation, collector
+ if o.columns.any?
+ collector << " (#{o.columns.map { |x|
+ quote_column_name x.name
+ }.join ', '})"
+ end
+
+ if o.values
+ maybe_visit o.values, collector
+ elsif o.select
+ maybe_visit o.select, collector
+ else
+ collector
+ end
+ end
+
+ def visit_Arel_Nodes_Exists o, collector
+ collector << "EXISTS ("
+ collector = visit(o.expressions, collector) << ")"
+ if o.alias
+ collector << " AS "
+ visit o.alias, collector
+ else
+ collector
+ end
+ end
+
+ def visit_Arel_Nodes_Casted o, collector
+ collector << quoted(o.val, o.attribute).to_s
+ end
+
+ def visit_Arel_Nodes_Quoted o, collector
+ collector << quoted(o.expr, nil).to_s
+ end
+
+ def visit_Arel_Nodes_True o, collector
+ collector << "TRUE"
+ end
+
+ def visit_Arel_Nodes_False o, collector
+ collector << "FALSE"
+ end
+
+ def visit_Arel_Nodes_ValuesList o, collector
+ collector << "VALUES "
+
+ len = o.rows.length - 1
+ o.rows.each_with_index { |row, i|
+ collector << '('
+ row_len = row.length - 1
+ row.each_with_index do |value, k|
+ case value
+ when Nodes::SqlLiteral, Nodes::BindParam
+ collector = visit(value, collector)
+ else
+ collector << quote(value)
+ end
+ collector << COMMA unless k == row_len
+ end
+ collector << ')'
+ collector << COMMA unless i == len
+ }
+ collector
+ end
+
+ def visit_Arel_Nodes_Values o, collector
+ collector << "VALUES ("
+
+ len = o.expressions.length - 1
+ o.expressions.each_with_index { |value, i|
+ case value
+ when Nodes::SqlLiteral, Nodes::BindParam
+ collector = visit value, collector
+ else
+ collector << quote(value).to_s
+ end
+ unless i == len
+ collector << COMMA
+ end
+ }
+
+ collector << ")"
+ end
+
+ def visit_Arel_Nodes_SelectStatement o, collector
+ if o.with
+ collector = visit o.with, collector
+ collector << SPACE
+ end
+
+ collector = o.cores.inject(collector) { |c,x|
+ visit_Arel_Nodes_SelectCore(x, c)
+ }
+
+ unless o.orders.empty?
+ collector << ORDER_BY
+ len = o.orders.length - 1
+ o.orders.each_with_index { |x, i|
+ collector = visit(x, collector)
+ collector << COMMA unless len == i
+ }
+ end
+
+ visit_Arel_Nodes_SelectOptions(o, collector)
+
+ collector
+ end
+
+ def visit_Arel_Nodes_SelectOptions o, collector
+ collector = maybe_visit o.limit, collector
+ collector = maybe_visit o.offset, collector
+ collector = maybe_visit o.lock, collector
+ end
+
+ 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
+
+ if o.source && !o.source.empty?
+ collector << " FROM "
+ collector = visit o.source, collector
+ end
+
+ 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.windows, collector, WINDOW
+
+ collector
+ end
+
+ 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
+ end
+ end
+
+ def visit_Arel_Nodes_Bin o, collector
+ visit o.expr, collector
+ end
+
+ def visit_Arel_Nodes_Distinct o, collector
+ collector << DISTINCT
+ end
+
+ def visit_Arel_Nodes_DistinctOn o, collector
+ raise NotImplementedError, 'DISTINCT ON not implemented for this db'
+ end
+
+ def visit_Arel_Nodes_With o, collector
+ collector << "WITH "
+ inject_join o.children, collector, COMMA
+ end
+
+ def visit_Arel_Nodes_WithRecursive o, collector
+ collector << "WITH RECURSIVE "
+ inject_join o.children, collector, COMMA
+ end
+
+ def visit_Arel_Nodes_Union o, collector
+ collector << "( "
+ infix_value(o, collector, " UNION ") << " )"
+ end
+
+ def visit_Arel_Nodes_UnionAll o, collector
+ collector << "( "
+ infix_value(o, collector, " UNION ALL ") << " )"
+ end
+
+ def visit_Arel_Nodes_Intersect o, collector
+ collector << "( "
+ infix_value(o, collector, " INTERSECT ") << " )"
+ end
+
+ def visit_Arel_Nodes_Except o, collector
+ collector << "( "
+ infix_value(o, collector, " EXCEPT ") << " )"
+ end
+
+ def visit_Arel_Nodes_NamedWindow o, collector
+ collector << quote_column_name(o.name)
+ collector << " AS "
+ visit_Arel_Nodes_Window o, collector
+ end
+
+ def visit_Arel_Nodes_Window o, collector
+ collector << "("
+
+ if o.partitions.any?
+ collector << "PARTITION BY "
+ collector = inject_join o.partitions, collector, ", "
+ end
+
+ if o.orders.any?
+ collector << SPACE if o.partitions.any?
+ collector << "ORDER BY "
+ collector = inject_join o.orders, collector, ", "
+ end
+
+ if o.framing
+ collector << SPACE if o.partitions.any? or o.orders.any?
+ collector = visit o.framing, collector
+ end
+
+ collector << ")"
+ end
+
+ def visit_Arel_Nodes_Rows o, collector
+ if o.expr
+ collector << "ROWS "
+ visit o.expr, collector
+ else
+ collector << "ROWS"
+ end
+ end
+
+ def visit_Arel_Nodes_Range o, collector
+ if o.expr
+ collector << "RANGE "
+ visit o.expr, collector
+ else
+ collector << "RANGE"
+ end
+ end
+
+ def visit_Arel_Nodes_Preceding o, collector
+ collector = if o.expr
+ visit o.expr, collector
+ else
+ collector << "UNBOUNDED"
+ end
+
+ collector << " PRECEDING"
+ end
+
+ def visit_Arel_Nodes_Following o, collector
+ collector = if o.expr
+ visit o.expr, collector
+ else
+ collector << "UNBOUNDED"
+ end
+
+ collector << " FOLLOWING"
+ end
+
+ def visit_Arel_Nodes_CurrentRow o, collector
+ collector << "CURRENT ROW"
+ end
+
+ def visit_Arel_Nodes_Over o, collector
+ case o.right
+ when nil
+ visit(o.left, collector) << " OVER ()"
+ when Arel::Nodes::SqlLiteral
+ infix_value o, collector, " OVER "
+ when String, Symbol
+ visit(o.left, collector) << " OVER #{quote_column_name o.right.to_s}"
+ else
+ infix_value o, collector, " OVER "
+ end
+ end
+
+ def visit_Arel_Nodes_Offset o, collector
+ collector << "OFFSET "
+ visit o.expr, collector
+ end
+
+ def visit_Arel_Nodes_Limit o, collector
+ collector << "LIMIT "
+ 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
+
+ def visit_Arel_Nodes_Grouping o, collector
+ if o.expr.is_a? Nodes::Grouping
+ visit(o.expr, collector)
+ else
+ collector << "("
+ visit(o.expr, collector) << ")"
+ end
+ end
+
+ def visit_Arel_SelectManager o, collector
+ collector << '('
+ visit(o.ast, collector) << ')'
+ end
+
+ def visit_Arel_Nodes_Ascending o, collector
+ visit(o.expr, collector) << " ASC"
+ end
+
+ def visit_Arel_Nodes_Descending o, collector
+ visit(o.expr, collector) << " DESC"
+ end
+
+ def visit_Arel_Nodes_Group o, collector
+ visit o.expr, collector
+ end
+
+ def visit_Arel_Nodes_NamedFunction o, collector
+ collector << o.name
+ collector << "("
+ collector << "DISTINCT " if o.distinct
+ collector = inject_join(o.expressions, collector, ", ") << ")"
+ if o.alias
+ collector << " AS "
+ visit o.alias, collector
+ else
+ collector
+ end
+ end
+
+ def visit_Arel_Nodes_Extract o, collector
+ collector << "EXTRACT(#{o.field.to_s.upcase} FROM "
+ visit(o.expr, collector) << ")"
+ end
+
+ def visit_Arel_Nodes_Count o, collector
+ aggregate "COUNT", o, collector
+ end
+
+ def visit_Arel_Nodes_Sum o, collector
+ aggregate "SUM", o, collector
+ end
+
+ def visit_Arel_Nodes_Max o, collector
+ aggregate "MAX", o, collector
+ end
+
+ def visit_Arel_Nodes_Min o, collector
+ aggregate "MIN", o, collector
+ end
+
+ def visit_Arel_Nodes_Avg o, collector
+ aggregate "AVG", o, collector
+ end
+
+ def visit_Arel_Nodes_TableAlias o, collector
+ collector = visit o.relation, collector
+ collector << " "
+ collector << quote_table_name(o.name)
+ end
+
+ def visit_Arel_Nodes_Between o, collector
+ collector = visit o.left, collector
+ collector << " BETWEEN "
+ visit o.right, collector
+ end
+
+ def visit_Arel_Nodes_GreaterThanOrEqual o, collector
+ collector = visit o.left, collector
+ collector << " >= "
+ visit o.right, collector
+ end
+
+ def visit_Arel_Nodes_GreaterThan o, collector
+ collector = visit o.left, collector
+ collector << " > "
+ visit o.right, collector
+ end
+
+ def visit_Arel_Nodes_LessThanOrEqual o, collector
+ collector = visit o.left, collector
+ collector << " <= "
+ visit o.right, collector
+ end
+
+ def visit_Arel_Nodes_LessThan o, collector
+ collector = visit o.left, collector
+ collector << " < "
+ visit o.right, collector
+ end
+
+ def visit_Arel_Nodes_Matches o, collector
+ collector = visit o.left, collector
+ collector << " LIKE "
+ collector = visit o.right, collector
+ if o.escape
+ collector << ' ESCAPE '
+ visit o.escape, collector
+ else
+ collector
+ end
+ end
+
+ def visit_Arel_Nodes_DoesNotMatch o, collector
+ collector = visit o.left, collector
+ collector << " NOT LIKE "
+ collector = visit o.right, collector
+ if o.escape
+ collector << ' ESCAPE '
+ visit o.escape, collector
+ else
+ collector
+ end
+ end
+
+ def visit_Arel_Nodes_JoinSource o, collector
+ if o.left
+ collector = visit o.left, collector
+ end
+ if o.right.any?
+ collector << SPACE if o.left
+ collector = inject_join o.right, collector, SPACE
+ end
+ collector
+ end
+
+ def visit_Arel_Nodes_Regexp o, collector
+ raise NotImplementedError, '~ not implemented for this db'
+ end
+
+ def visit_Arel_Nodes_NotRegexp o, collector
+ raise NotImplementedError, '!~ not implemented for this db'
+ end
+
+ def visit_Arel_Nodes_StringJoin o, collector
+ visit o.left, collector
+ end
+
+ def visit_Arel_Nodes_FullOuterJoin o, collector
+ collector << "FULL OUTER JOIN "
+ collector = visit o.left, collector
+ collector << SPACE
+ visit o.right, collector
+ end
+
+ def visit_Arel_Nodes_OuterJoin o, collector
+ collector << "LEFT OUTER JOIN "
+ collector = visit o.left, collector
+ collector << " "
+ visit o.right, collector
+ end
+
+ def visit_Arel_Nodes_RightOuterJoin o, collector
+ collector << "RIGHT OUTER JOIN "
+ collector = visit o.left, collector
+ collector << SPACE
+ visit o.right, collector
+ end
+
+ def visit_Arel_Nodes_InnerJoin o, collector
+ collector << "INNER JOIN "
+ collector = visit o.left, collector
+ if o.right
+ collector << SPACE
+ visit(o.right, collector)
+ else
+ collector
+ end
+ end
+
+ def visit_Arel_Nodes_On o, collector
+ collector << "ON "
+ visit o.expr, collector
+ end
+
+ def visit_Arel_Nodes_Not o, collector
+ collector << "NOT ("
+ visit(o.expr, collector) << ")"
+ end
+
+ def visit_Arel_Table o, collector
+ if o.table_alias
+ collector << "#{quote_table_name o.name} #{quote_table_name o.table_alias}"
+ else
+ collector << quote_table_name(o.name)
+ end
+ end
+
+ def visit_Arel_Nodes_In o, collector
+ if Array === o.right && o.right.empty?
+ collector << '1=0'
+ else
+ collector = visit o.left, collector
+ collector << " IN ("
+ visit(o.right, collector) << ")"
+ end
+ end
+
+ def visit_Arel_Nodes_NotIn o, collector
+ if Array === o.right && o.right.empty?
+ collector << '1=1'
+ else
+ collector = visit o.left, collector
+ collector << " NOT IN ("
+ collector = visit o.right, collector
+ collector << ")"
+ end
+ end
+
+ def visit_Arel_Nodes_And o, collector
+ inject_join o.children, collector, " AND "
+ end
+
+ def visit_Arel_Nodes_Or o, collector
+ collector = visit o.left, collector
+ collector << " OR "
+ visit o.right, collector
+ end
+
+ def visit_Arel_Nodes_Assignment o, collector
+ case o.right
+ when Arel::Nodes::UnqualifiedColumn, Arel::Attributes::Attribute, Arel::Nodes::BindParam
+ collector = visit o.left, collector
+ collector << " = "
+ visit o.right, collector
+ else
+ collector = visit o.left, collector
+ collector << " = "
+ collector << quote(o.right).to_s
+ end
+ end
+
+ def visit_Arel_Nodes_Equality o, collector
+ right = o.right
+
+ collector = visit o.left, collector
+
+ if right.nil?
+ collector << " IS NULL"
+ else
+ collector << " = "
+ visit right, collector
+ end
+ end
+
+ def visit_Arel_Nodes_NotEqual o, collector
+ right = o.right
+
+ collector = visit o.left, collector
+
+ if right.nil?
+ collector << " IS NOT NULL"
+ else
+ collector << " != "
+ visit right, collector
+ end
+ end
+
+ def visit_Arel_Nodes_As o, collector
+ collector = visit o.left, collector
+ collector << " AS "
+ visit o.right, collector
+ end
+
+ def visit_Arel_Nodes_Case o, collector
+ collector << "CASE "
+ if o.case
+ visit o.case, collector
+ collector << " "
+ end
+ o.conditions.each do |condition|
+ visit condition, collector
+ collector << " "
+ end
+ if o.default
+ visit o.default, collector
+ collector << " "
+ end
+ collector << "END"
+ end
+
+ def visit_Arel_Nodes_When o, collector
+ collector << "WHEN "
+ visit o.left, collector
+ collector << " THEN "
+ visit o.right, collector
+ end
+
+ def visit_Arel_Nodes_Else o, collector
+ collector << "ELSE "
+ visit o.expr, collector
+ end
+
+ def visit_Arel_Nodes_UnqualifiedColumn o, collector
+ collector << "#{quote_column_name o.name}"
+ collector
+ end
+
+ def visit_Arel_Attributes_Attribute o, collector
+ join_name = o.relation.table_alias || o.relation.name
+ collector << "#{quote_table_name join_name}.#{quote_column_name o.name}"
+ end
+ alias :visit_Arel_Attributes_Integer :visit_Arel_Attributes_Attribute
+ alias :visit_Arel_Attributes_Float :visit_Arel_Attributes_Attribute
+ alias :visit_Arel_Attributes_Decimal :visit_Arel_Attributes_Attribute
+ alias :visit_Arel_Attributes_String :visit_Arel_Attributes_Attribute
+ alias :visit_Arel_Attributes_Time :visit_Arel_Attributes_Attribute
+ alias :visit_Arel_Attributes_Boolean :visit_Arel_Attributes_Attribute
+
+ def literal o, collector; collector << o.to_s; end
+
+ def visit_Arel_Nodes_BindParam o, collector
+ collector.add_bind(o.value) { "?" }
+ end
+
+ alias :visit_Arel_Nodes_SqlLiteral :literal
+ alias :visit_Bignum :literal
+ alias :visit_Fixnum :literal
+ alias :visit_Integer :literal
+
+ def quoted o, a
+ if a && a.able_to_type_cast?
+ quote(a.type_cast_for_database(o))
+ else
+ quote(o)
+ end
+ end
+
+ def unsupported o, collector
+ raise UnsupportedVisitError.new(o)
+ end
+
+ alias :visit_ActiveSupport_Multibyte_Chars :unsupported
+ alias :visit_ActiveSupport_StringInquirer :unsupported
+ alias :visit_BigDecimal :unsupported
+ alias :visit_Class :unsupported
+ alias :visit_Date :unsupported
+ alias :visit_DateTime :unsupported
+ alias :visit_FalseClass :unsupported
+ alias :visit_Float :unsupported
+ alias :visit_Hash :unsupported
+ alias :visit_NilClass :unsupported
+ alias :visit_String :unsupported
+ alias :visit_Symbol :unsupported
+ alias :visit_Time :unsupported
+ alias :visit_TrueClass :unsupported
+
+ def visit_Arel_Nodes_InfixOperation o, collector
+ collector = visit o.left, collector
+ collector << " #{o.operator} "
+ visit o.right, collector
+ end
+
+ alias :visit_Arel_Nodes_Addition :visit_Arel_Nodes_InfixOperation
+ alias :visit_Arel_Nodes_Subtraction :visit_Arel_Nodes_InfixOperation
+ alias :visit_Arel_Nodes_Multiplication :visit_Arel_Nodes_InfixOperation
+ alias :visit_Arel_Nodes_Division :visit_Arel_Nodes_InfixOperation
+
+ def visit_Arel_Nodes_UnaryOperation o, collector
+ collector << " #{o.operator} "
+ visit o.expr, collector
+ end
+
+ def visit_Array o, collector
+ inject_join o, collector, ", "
+ end
+ alias :visit_Set :visit_Array
+
+ def quote value
+ return value if Arel::Nodes::SqlLiteral === value
+ @connection.quote value
+ end
+
+ def quote_table_name name
+ return name if Arel::Nodes::SqlLiteral === name
+ @connection.quote_table_name(name)
+ end
+
+ def quote_column_name name
+ return name if Arel::Nodes::SqlLiteral === name
+ @connection.quote_column_name(name)
+ end
+
+ def maybe_visit thing, collector
+ return collector unless thing
+ collector << " "
+ visit thing, collector
+ end
+
+ def inject_join list, collector, join_str
+ len = list.length - 1
+ list.each_with_index.inject(collector) { |c, (x,i)|
+ if i == len
+ visit x, c
+ else
+ visit(x, c) << join_str
+ end
+ }
+ end
+
+ def infix_value o, collector, value
+ collector = visit o.left, collector
+ collector << value
+ visit o.right, collector
+ end
+
+ def aggregate name, o, collector
+ collector << "#{name}("
+ if o.distinct
+ collector << "DISTINCT "
+ end
+ collector = inject_join(o.expressions, collector, ", ") << ")"
+ if o.alias
+ collector << " AS "
+ visit o.alias, collector
+ else
+ collector
+ end
+ end
+ end
+ end
+end
diff --git a/activerecord/lib/arel/visitors/visitor.rb b/activerecord/lib/arel/visitors/visitor.rb
new file mode 100644
index 0000000000..f156be9a0a
--- /dev/null
+++ b/activerecord/lib/arel/visitors/visitor.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+module Arel
+ module Visitors
+ class Visitor
+ def initialize
+ @dispatch = get_dispatch_cache
+ end
+
+ def accept object, *args
+ visit object, *args
+ end
+
+ private
+
+ attr_reader :dispatch
+
+ def self.dispatch_cache
+ Hash.new do |hash, klass|
+ hash[klass] = "visit_#{(klass.name || '').gsub('::', '_')}"
+ end
+ end
+
+ def get_dispatch_cache
+ self.class.dispatch_cache
+ end
+
+ def visit object, *args
+ dispatch_method = dispatch[object.class]
+ send dispatch_method, object, *args
+ rescue NoMethodError => e
+ raise e if respond_to?(dispatch_method, true)
+ superklass = object.class.ancestors.find { |klass|
+ respond_to?(dispatch[klass], true)
+ }
+ raise(TypeError, "Cannot visit #{object.class}") unless superklass
+ dispatch[object.class] = dispatch[superklass]
+ retry
+ end
+ end
+ end
+end
diff --git a/activerecord/lib/arel/visitors/where_sql.rb b/activerecord/lib/arel/visitors/where_sql.rb
new file mode 100644
index 0000000000..55e6ca9a21
--- /dev/null
+++ b/activerecord/lib/arel/visitors/where_sql.rb
@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+module Arel
+ module Visitors
+ class WhereSql < Arel::Visitors::ToSql
+ def initialize(inner_visitor, *args, &block)
+ @inner_visitor = inner_visitor
+ super(*args, &block)
+ end
+
+ private
+
+ def visit_Arel_Nodes_SelectCore o, collector
+ collector << "WHERE "
+ wheres = o.wheres.map do |where|
+ Nodes::SqlLiteral.new(@inner_visitor.accept(where, collector.class.new).value)
+ end
+
+ inject_join wheres, collector, ' AND '
+ end
+ end
+ end
+end