diff options
-rw-r--r-- | lib/arel/visitors/oracle.rb | 6 | ||||
-rw-r--r-- | spec/crud_spec.rb | 2 | ||||
-rw-r--r-- | spec/visitors/oracle_spec.rb | 10 |
3 files changed, 16 insertions, 2 deletions
diff --git a/lib/arel/visitors/oracle.rb b/lib/arel/visitors/oracle.rb index 659b75f16d..c691ce294e 100644 --- a/lib/arel/visitors/oracle.rb +++ b/lib/arel/visitors/oracle.rb @@ -6,7 +6,9 @@ module Arel def visit_Arel_Nodes_SelectStatement o o = order_hacks(o) - if o.limit && o.orders.empty? && !o.offset + # 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 / o.cores.last.wheres.push Nodes::LessThanOrEqual.new( Nodes::SqlLiteral.new('ROWNUM'), o.limit ) @@ -31,7 +33,7 @@ module Arel eosql end - if o.limit && !o.orders.empty? + if o.limit o = o.dup limit = o.limit o.limit = nil diff --git a/spec/crud_spec.rb b/spec/crud_spec.rb index 3485df6685..36b2a0b4e4 100644 --- a/spec/crud_spec.rb +++ b/spec/crud_spec.rb @@ -1,3 +1,5 @@ +require 'spec_helper' + module Arel class FakeCrudder < SelectManager class FakeEngine diff --git a/spec/visitors/oracle_spec.rb b/spec/visitors/oracle_spec.rb index cdf0e3427f..93ade3ef3c 100644 --- a/spec/visitors/oracle_spec.rb +++ b/spec/visitors/oracle_spec.rb @@ -71,6 +71,16 @@ module Arel } end + it 'creates a subquery when there is DISTINCT' do + stmt = Nodes::SelectStatement.new + stmt.cores.first.projections << Nodes::SqlLiteral.new('DISTINCT id') + stmt.limit = 10 + sql = @visitor.accept stmt + sql.should be_like %{ + SELECT * FROM (SELECT DISTINCT id) WHERE ROWNUM <= 10 + } + end + it 'creates a different subquery when there is an offset' do stmt = Nodes::SelectStatement.new stmt.limit = 10 |