Made schema dumper recognize partial indices' where statements

7 files changed, 27 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
index 132ca10f79..ad2e8634eb 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -6,7 +6,7 @@ require 'bigdecimal/util'
 
 module ActiveRecord
   module ConnectionAdapters #:nodoc:
-    class IndexDefinition < Struct.new(:table, :name, :unique, :columns, :lengths, :orders) #:nodoc:
+    class IndexDefinition < Struct.new(:table, :name, :unique, :columns, :lengths, :orders, :where) #:nodoc:
     end
 
     # Abstract representation of a column definition. Instances of this type
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index da5d6fcf3c..f1940ea15f 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -889,8 +889,9 @@ module ActiveRecord
           # add info on sort order for columns (only desc order is explicitly specified, asc is the default)
           desc_order_columns = inddef.scan(/(\w+) DESC/).flatten
           orders = desc_order_columns.any? ? Hash[desc_order_columns.map {|order_column| [order_column, :desc]}] : {}
+          where = inddef.scan(/WHERE (.+)$/).flatten[0]
 
-          column_names.empty? ? nil : IndexDefinition.new(table_name, index_name, unique, column_names, [], orders)
+          column_names.empty? ? nil : IndexDefinition.new(table_name, index_name, unique, column_names, [], orders, where)
         end.compact
       end
 
diff --git a/activerecord/lib/active_record/schema_dumper.rb b/activerecord/lib/active_record/schema_dumper.rb
index 2a565b51c6..dcbd165e58 100644
--- a/activerecord/lib/active_record/schema_dumper.rb
+++ b/activerecord/lib/active_record/schema_dumper.rb
@@ -197,6 +197,8 @@ HEADER
             index_orders = (index.orders || {})
             statement_parts << (':order => ' + index.orders.inspect) unless index_orders.empty?
 
+            statement_parts << (':where => ' + index.where.inspect) if index.where
+
             '  ' + statement_parts.join(', ')
           end
 
diff --git a/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb b/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb
index d57794daf8..898d28456b 100644
--- a/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb
@@ -179,6 +179,12 @@ module ActiveRecord
         assert_equal Arel.sql('$2'), bind
       end
 
+      def test_partial_index
+        @connection.add_index 'ex', %w{ id number }, :name => 'partial', :where => "number > 100"
+        index = @connection.indexes('ex').find { |idx| idx.name == 'partial' }
+        assert_equal "(number > 100)", index.where
+      end
+
       private
       def insert(ctx, data)
         binds   = data.map { |name, value|
diff --git a/activerecord/test/cases/migration/index_test.rb b/activerecord/test/cases/migration/index_test.rb
index 89cf0f5e93..c5a479fcdb 100644
--- a/activerecord/test/cases/migration/index_test.rb
+++ b/activerecord/test/cases/migration/index_test.rb
@@ -169,6 +169,12 @@ module ActiveRecord
           connection.add_index("testings", ["last_name", "first_name"], :order => :desc)
           connection.remove_index("testings", ["last_name", "first_name"])
         end
+
+        # Selected adapters support partial indices
+        if current_adapter?(:PostgreSQLAdapter)
+          connection.add_index("testings", ["last_name"], :where => "first_name = 'john doe'")
+          connection.remove_index("testings", ["last_name"])
+        end
       end
 
     end
diff --git a/activerecord/test/cases/schema_dumper_test.rb b/activerecord/test/cases/schema_dumper_test.rb
index abeb56fd3f..c79382a984 100644
--- a/activerecord/test/cases/schema_dumper_test.rb
+++ b/activerecord/test/cases/schema_dumper_test.rb
@@ -185,6 +185,15 @@ class SchemaDumperTest < ActiveRecord::TestCase
     assert_equal 'add_index "companies", ["firm_id", "type", "rating", "ruby_type"], :name => "company_index"', index_definition
   end
 
+  def test_schema_dumps_partial_indices
+    index_definition = standard_dump.split(/\n/).grep(/add_index.*company_partial_index/).first.strip
+    if current_adapter?(:PostgreSQLAdapter)
+      assert_equal 'add_index "companies", ["firm_id", "type"], :name => "company_partial_index", :where => "(rating > 10)"', index_definition
+    else
+      assert_equal 'add_index "companies", ["firm_id", "type"], :name => "company_partial_index"', index_definition
+    end
+  end
+
   def test_schema_dump_should_honor_nonstandard_primary_keys
     output = standard_dump
     match = output.match(%r{create_table "movies"(.*)do})
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index da0c4cecdd..d473680fdc 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -175,6 +175,7 @@ ActiveRecord::Schema.define do
   end
 
   add_index :companies, [:firm_id, :type, :rating, :ruby_type], :name => "company_index"
+  add_index :companies, [:firm_id, :type], :name => "company_partial_index", :where => "rating > 10"
 
   create_table :computers, :force => true do |t|
     t.integer :developer, :null => false