require 'bigdecimal'
require 'date'
module Arel
module Visitors
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.
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
private
def visit_Arel_Nodes_DeleteStatement o, a
[
"DELETE FROM #{visit o.relation}",
("WHERE #{o.wheres.map { |x| visit x }.join AND}" unless o.wheres.empty?)
].compact.join ' '
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, a
if o.orders.empty? && o.limit.nil?
wheres = o.wheres
else
wheres = [Nodes::In.new(o.key, [build_subselect(o.key, o)])]
end
[
"UPDATE #{visit o.relation, a}",
("SET #{o.values.map { |value| visit value, a }.join ', '}" unless o.values.empty?),
("WHERE #{wheres.map { |x| visit x, a }.join ' AND '}" unless wheres.empty?),
].compact.join ' '
end
def visit_Arel_Nodes_InsertStatement o, a
[
"INSERT INTO #{visit o.relation, a}",
("(#{o.columns.map { |x|
quote_column_name x.name
}.join ', '})" unless o.columns.empty?),
(visit o.values, a if o.values),
].compact.join ' '
end
def visit_Arel_Nodes_Exists o, a
"EXISTS (#{visit o.expressions, a})#{
o.alias ? " AS #{visit o.alias, a}" : ''}"
end
def visit_Arel_Nodes_True o, a
"TRUE"
end
def visit_Arel_Nodes_False o, a
"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, a
"VALUES (#{o.expressions.zip(o.columns).map { |value, attr|
if Nodes::SqlLiteral === value
visit value, a
else
quote(value, attr && column_for(attr))
end
}.join ', '})"
end
def visit_Arel_Nodes_SelectStatement o, a
str = ''
if o.with
str << visit(o.with, a)
str << SPACE
end
o.cores.each { |x| str << visit_Arel_Nodes_SelectCore(x, a) }
unless o.orders.empty?
str << SPACE
str << ORDER_BY
len = o.orders.length - 1
o.orders.each_with_index { |x, i|
str << visit(x, a)
str << COMMA unless len == i
}
end
str << " #{visit(o.limit, a)}" if o.limit
str << " #{visit(o.offset, a)}" if o.offset
str << " #{visit(o.lock, a)}" if o.lock
str.strip!
str
end
def visit_Arel_Nodes_SelectCore o, a
str = "SELECT"
str << " #{visit(o.top, a)}" if o.top
str << " #{visit(o.set_quantifier, a)}" if o.set_quantifier
unless o.projections.empty?
str << SPACE
len = o.projections.length - 1
o.projections.each_with_index do |x, i|
str << visit(x, a)
str << COMMA unless len == i
end
end
str << " FROM #{visit(o.source, a)}" if o.source && !o.source.empty?
unless o.wheres.empty?
str << WHERE
len = o.wheres.length - 1
o.wheres.each_with_index do |x, i|
str << visit(x, a)
str << AND unless len == i
end
end
unless o.groups.empty?
str << GROUP_BY
len = o.groups.length - 1
o.groups.each_with_index do |x, i|
str << visit(x, a)
str << COMMA unless len == i
end
end
str << " #{visit(o.having, a)}" if o.having
unless o.windows.empty?
str << WINDOW
len = o.windows.length - 1
o.windows.each_with_index do |x, i|
str << visit(x, a)
str << COMMA unless len == i
end
end
str
end
def visit_Arel_Nodes_Bin o, a
visit o.expr, a
end
def visit_Arel_Nodes_Distinct o, a
DISTINCT
end
def visit_Arel_Nodes_DistinctOn o, a
raise NotImplementedError, 'DISTINCT ON not implemented for this db'
end
def visit_Arel_Nodes_With o, a
"WITH #{o.children.map { |x| visit x, a }.join(', ')}"
end
def visit_Arel_Nodes_WithRecursive o, a
"WITH RECURSIVE #{o.children.map { |x| visit x, a }.join(', ')}"
end
def visit_Arel_Nodes_Union o, a
"( #{visit o.left, a} UNION #{visit o.right, a} )"
end
def visit_Arel_Nodes_UnionAll o, a
"( #{visit o.left, a} UNION ALL #{visit o.right, a} )"
end
def visit_Arel_Nodes_Intersect o, a
"( #{visit o.left, a} INTERSECT #{visit o.right, a} )"
end
def visit_Arel_Nodes_Except o, a
"( #{visit o.left, a} EXCEPT #{visit o.right, a} )"
end
def visit_Arel_Nodes_NamedWindow o, a
"#{quote_column_name o.name} AS #{visit_Arel_Nodes_Window o, a}"
end
def visit_Arel_Nodes_Window o, a
s = [
("ORDER BY #{o.orders.map { |x| visit(x, a) }.join(', ')}" unless o.orders.empty?),
(visit o.framing, a if o.framing)
].compact.join ' '
"(#{s})"
end
def visit_Arel_Nodes_Rows o, a
if o.expr
"ROWS #{visit o.expr, a}"
else
"ROWS"
end
end
def visit_Arel_Nodes_Range o, a
if o.expr
"RANGE #{visit o.expr, a}"
else
"RANGE"
end
end
def visit_Arel_Nodes_Preceding o, a
"#{o.expr ? visit(o.expr, a) : 'UNBOUNDED'} PRECEDING"
end
def visit_Arel_Nodes_Following o, a
"#{o.expr ? visit(o.expr, a) : 'UNBOUNDED'} FOLLOWING"
end
def visit_Arel_Nodes_CurrentRow o, a
"CURRENT ROW"
end
def visit_Arel_Nodes_Over o, a
case o.right
when nil
"#{visit o.left, a} OVER ()"
when Arel::Nodes::SqlLiteral
"#{visit o.left, a} OVER #{visit o.right, a}"
when String, Symbol
"#{visit o.left, a} OVER #{quote_column_name o.right.to_s}"
else
"#{visit o.left, a} OVER #{visit o.right, a}"
end
end
def visit_Arel_Nodes_Having o, a
"HAVING #{visit o.expr, a}"
end
def visit_Arel_Nodes_Offset o, a
"OFFSET #{visit o.expr, a}"
end
def visit_Arel_Nodes_Limit o, a
"LIMIT #{visit o.expr, a}"
end
# FIXME: this does nothing on most databases, but does on MSSQL
def visit_Arel_Nodes_Top o, a
""
end
def visit_Arel_Nodes_Lock o, a
visit o.expr, a
end
def visit_Arel_Nodes_Grouping o, a
"(#{visit o.expr, a})"
end
def visit_Arel_SelectManager o, a
"(#{o.to_sql.rstrip})"
end
def visit_Arel_Nodes_Ascending o, a
"#{visit o.expr, a} ASC"
end
def visit_Arel_Nodes_Descending o, a
"#{visit o.expr, a} DESC"
end
def visit_Arel_Nodes_Group o, a
visit o.expr, a
end
def visit_Arel_Nodes_NamedFunction o, a
"#{o.name}(#{o.distinct ? 'DISTINCT ' : ''}#{o.expressions.map { |x|
visit x, a
}.join(', ')})#{o.alias ? " AS #{visit o.alias, a}" : ''}"
end
def visit_Arel_Nodes_Extract o, a
"EXTRACT(#{o.field.to_s.upcase} FROM #{visit o.expr, a})#{o.alias ? " AS #{visit o.alias, a}" : ''}"
end
def visit_Arel_Nodes_Count o, a
"COUNT(#{o.distinct ? 'DISTINCT ' : ''}#{o.expressions.map { |x|
visit x, a
}.join(', ')})#{o.alias ? " AS #{visit o.alias, a}" : ''}"
end
def visit_Arel_Nodes_Sum o, a
"SUM(#{o.distinct ? 'DISTINCT ' : ''}#{o.expressions.map { |x|
visit x, a }.join(', ')})#{o.alias ? " AS #{visit o.alias, a}" : ''}"
end
def visit_Arel_Nodes_Max o, a
"MAX(#{o.distinct ? 'DISTINCT ' : ''}#{o.expressions.map { |x|
visit x, a }.join(', ')})#{o.alias ? " AS #{visit o.alias, a}" : ''}"
end
def visit_Arel_Nodes_Min o, a
"MIN(#{o.distinct ? 'DISTINCT ' : ''}#{o.expressions.map { |x|
visit x, a }.join(', ')})#{o.alias ? " AS #{visit o.alias, a}" : ''}"
end
def visit_Arel_Nodes_Avg o, a
"AVG(#{o.distinct ? 'DISTINCT ' : ''}#{o.expressions.map { |x|
visit x, a }.join(', ')})#{o.alias ? " AS #{visit o.alias, a}" : ''}"
end
def visit_Arel_Nodes_TableAlias o, a
"#{visit o.relation, a} #{quote_table_name o.name}"
end
def visit_Arel_Nodes_Between o, a
a = o.left if Arel::Attributes::Attribute === o.left
"#{visit o.left, a} BETWEEN #{visit o.right, a}"
end
def visit_Arel_Nodes_GreaterThanOrEqual o, a
a = o.left if Arel::Attributes::Attribute === o.left
"#{visit o.left, a} >= #{visit o.right, a}"
end
def visit_Arel_Nodes_GreaterThan o, a
a = o.left if Arel::Attributes::Attribute === o.left
"#{visit o.left, a} > #{visit o.right, a}"
end
def visit_Arel_Nodes_LessThanOrEqual o, a
a = o.left if Arel::Attributes::Attribute === o.left
"#{visit o.left, a} <= #{visit o.right, a}"
end
def visit_Arel_Nodes_LessThan o, a
a = o.left if Arel::Attributes::Attribute === o.left
"#{visit o.left, a} < #{visit o.right, a}"
end
def visit_Arel_Nodes_Matches o, a
a = o.left if Arel::Attributes::Attribute === o.left
"#{visit o.left, a} LIKE #{visit o.right, a}"
end
def visit_Arel_Nodes_DoesNotMatch o, a
a = o.left if Arel::Attributes::Attribute === o.left
"#{visit o.left, a} NOT LIKE #{visit o.right, a}"
end
def visit_Arel_Nodes_JoinSource o, a
[
(visit(o.left, a) if o.left),
o.right.map { |j| visit j, a }.join(' ')
].compact.join ' '
end
def visit_Arel_Nodes_StringJoin o, a
visit o.left, a
end
def visit_Arel_Nodes_OuterJoin o, a
"LEFT OUTER JOIN #{visit o.left, a} #{visit o.right, a}"
end
def visit_Arel_Nodes_InnerJoin o, a
s = "INNER JOIN #{visit o.left, a}"
if o.right
s << SPACE
s << visit(o.right, a)
end
s
end
def visit_Arel_Nodes_On o, a
"ON #{visit o.expr, a}"
end
def visit_Arel_Nodes_Not o, a
"NOT (#{visit o.expr, a})"
end
def visit_Arel_Table o, a
if o.table_alias
"#{quote_table_name o.name} #{quote_table_name o.table_alias}"
else
quote_table_name o.name
end
end
def visit_Arel_Nodes_In o, a
if Array === o.right && o.right.empty?
'1=0'
else
a = o.left if Arel::Attributes::Attribute === o.left
"#{visit o.left, a} IN (#{visit o.right, a})"
end
end
def visit_Arel_Nodes_NotIn o, a
if Array === o.right && o.right.empty?
'1=1'
else
a = o.left if Arel::Attributes::Attribute === o.left
"#{visit o.left, a} NOT IN (#{visit o.right, a})"
end
end
def visit_Arel_Nodes_And o, a
o.children.map { |x| visit x, a }.join ' AND '
end
def visit_Arel_Nodes_Or o, a
"#{visit o.left, a} OR #{visit o.right, a}"
end
def visit_Arel_Nodes_Assignment o, a
right = quote(o.right, column_for(o.left))
"#{visit o.left, a} = #{right}"
end
def visit_Arel_Nodes_Equality o, a
right = o.right
a = o.left if Arel::Attributes::Attribute === o.left
if right.nil?
"#{visit o.left, a} IS NULL"
else
"#{visit o.left, a} = #{visit right, a}"
end
end
def visit_Arel_Nodes_NotEqual o, a
right = o.right
a = o.left if Arel::Attributes::Attribute === o.left
if right.nil?
"#{visit o.left, a} IS NOT NULL"
else
"#{visit o.left, a} != #{visit right, a}"
end
end
def visit_Arel_Nodes_As o, a
"#{visit o.left, a} AS #{visit o.right, a}"
end
def visit_Arel_Nodes_UnqualifiedColumn o, a
"#{quote_column_name o.name}"
end
def visit_Arel_Attributes_Attribute o, a
join_name = o.relation.table_alias || o.relation.name
"#{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, a; o end
alias :visit_Arel_Nodes_BindParam :literal
alias :visit_Arel_Nodes_SqlLiteral :literal
alias :visit_Arel_SqlLiteral :literal # This is deprecated
alias :visit_Bignum :literal
alias :visit_Fixnum :literal
def quoted o, a
quote(o, column_for(a))
end
alias :visit_ActiveSupport_Multibyte_Chars :quoted
alias :visit_ActiveSupport_StringInquirer :quoted
alias :visit_BigDecimal :quoted
alias :visit_Class :quoted
alias :visit_Date :quoted
alias :visit_DateTime :quoted
alias :visit_FalseClass :quoted
alias :visit_Float :quoted
alias :visit_Hash :quoted
alias :visit_NilClass :quoted
alias :visit_String :quoted
alias :visit_Symbol :quoted
alias :visit_Time :quoted
alias :visit_TrueClass :quoted
def visit_Arel_Nodes_InfixOperation o, a
"#{visit o.left, a} #{o.operator} #{visit o.right, a}"
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, a
o.map { |x| visit x, a }.join(', ')
end
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
end
end
end