require 'bigdecimal'
require 'date'
require 'arel/visitors/reduce'
module Arel
module Visitors
class ToSql < Arel::Visitors::Reduce
##
# 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
@connection = connection
@schema_cache = connection.schema_cache
@quoted_tables = {}
@quoted_columns = {}
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 "
inject_join o.wheres, collector, AND
else
collector
end
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 table_exists? name
@schema_cache.table_exists? name
end
def column_for attr
return unless attr
name = attr.name.to_s
table = attr.relation.table_name
return nil unless table_exists? table
column_cache(table)[name]
end
def column_cache(table)
@schema_cache.columns_hash(table)
end
def visit_Arel_Nodes_Values o, collector
collector << "VALUES ("
len = o.expressions.length - 1
o.expressions.zip(o.columns).each_with_index { |(value, attr), i|
if Nodes::SqlLiteral === value
collector = visit value, collector
else
collector << quote(value, attr && column_for(attr)).to_s
end
unless i == len
collector << ', '
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 << SPACE
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
collector = maybe_visit o.limit, collector
collector = maybe_visit o.offset, collector
collector = maybe_visit o.lock, collector
collector
end
def visit_Arel_Nodes_SelectCore o, collector
collector << "SELECT"
if o.top
collector << " "
collector = visit o.top, collector
end
if o.set_quantifier
collector << " "
collector = visit o.set_quantifier, collector
end
unless o.projections.empty?
collector << SPACE
len = o.projections.length - 1
o.projections.each_with_index do |x, i|
collector = visit(x, collector)
collector << COMMA unless len == i
end
end
if o.source && !o.source.empty?
collector << " FROM "
collector = visit o.source, collector
end
unless o.wheres.empty?
collector << WHERE
len = o.wheres.length - 1
o.wheres.each_with_index do |x, i|
collector = visit(x, collector)
collector << AND unless len == i
end
end
unless o.groups.empty?
collector << GROUP_BY
len = o.groups.length - 1
o.groups.each_with_index do |x, i|
collector = visit(x, collector)
collector << COMMA unless len == i
end
end
if o.having
collector << " "
collector = visit(o.having, collector)
end
unless o.windows.empty?
collector << WINDOW
len = o.windows.length - 1
o.windows.each_with_index do |x, i|
collector = visit(x, collector)
collector << COMMA unless len == i
end
end
collector
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, ', '
end
def visit_Arel_Nodes_WithRecursive o, collector
collector << "WITH RECURSIVE "
inject_join o.children, collector, ', '
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 << ' ' if o.partitions.any?
collector << "ORDER BY "
collector = inject_join o.orders, collector, ", "
end
if o.framing
collector << ' ' 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_Having o, collector
collector << "HAVING "
visit o.expr, collector
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 << "(#{o.to_sql.rstrip})"
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 "
visit o.right, collector
end
def visit_Arel_Nodes_DoesNotMatch o, collector
collector = visit o.left, collector
collector << " NOT LIKE "
visit o.right, collector
end
def visit_Arel_Nodes_JoinSource o, collector
if o.left
collector = visit o.left, collector
end
if o.right.any?
collector << " " if o.left
collector = inject_join o.right, collector, ' '
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
"FULL OUTER JOIN #{visit o.left} #{visit o.right}"
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
"RIGHT OUTER JOIN #{visit o.left} #{visit o.right}"
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, column_for(o.left)).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_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
end
alias :visit_Arel_Nodes_SqlLiteral :literal
alias :visit_Bignum :literal
alias :visit_Fixnum :literal
def quoted o, a
quote(o, column_for(a))
end
def unsupported o, collector
raise "unsupported: #{o.class.name}"
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_Array o, collector
inject_join o, collector, ", "
end
alias :visit_Set :visit_Array
def quote value, column = nil
return value if Arel::Nodes::SqlLiteral === value
@connection.quote value, column
end
def quote_table_name name
return name if Arel::Nodes::SqlLiteral === name
@quoted_tables[name] ||= @connection.quote_table_name(name)
end
def quote_column_name name
@quoted_columns[name] ||= Arel::Nodes::SqlLiteral === name ? 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