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Support columns_for_distinct

This commit is contained in:
Yasuo Honda 2013-06-06 21:33:20 +09:00
parent bd6adc877a
commit 51f5bece08
2 changed files with 4 additions and 3 deletions

View file

@ -8,7 +8,7 @@ module Arel
# 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.offset && o.cores.first.projections.first !~ /^DISTINCT /
if o.limit && o.orders.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
)
@ -83,7 +83,7 @@ module Arel
return o if o.orders.empty?
return o unless o.cores.any? do |core|
core.projections.any? do |projection|
/DISTINCT.*FIRST_VALUE/ === projection
/FIRST_VALUE/ === projection
end
end
# Previous version with join and split broke ORDER BY clause

View file

@ -85,7 +85,8 @@ module Arel
it 'creates a subquery when there is DISTINCT' do
stmt = Nodes::SelectStatement.new
stmt.cores.first.projections << Nodes::SqlLiteral.new('DISTINCT id')
stmt.cores.first.set_quantifier = Arel::Nodes::Distinct.new
stmt.cores.first.projections << Nodes::SqlLiteral.new('id')
stmt.limit = Arel::Nodes::Limit.new(10)
sql = @visitor.accept stmt
sql.must_be_like %{