# frozen_string_literal: true
module Arel # :nodoc: all
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, collector = Arel::Collectors::SQLString.new, &block)
accept(node, collector, &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? || 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