diff --git a/lib/pg_searchable_regex.rb b/lib/pg_searchable_regex.rb
index 8c7374b..f6bce45 100644
--- a/lib/pg_searchable_regex.rb
+++ b/lib/pg_searchable_regex.rb
@@ -26,7 +26,7 @@ module PgSearchable
       wildcard: true,
       external_cache_data: nil,
       joins: [],
-      default_field: ""
+      default_fields: []
     )
       @ts_search_fields = fields
       @ts_search_fields_mappings = fields_mappings
@@ -36,14 +36,18 @@ module PgSearchable
       @ts_skip_cache_update = skip_callback
       @ts_wildcard = wildcard
       @ts_joins = joins
-      @default_field = default_field.to_s.empty? ? fields.first : default_field.to_sym
+      @default_fields = if default_fields.is_a? Array
+                          default_fields.empty? ? [fields.first] : default_fields
+                        else
+                          default_fields.to_s.empty? ? [fields.first] : [default_fields.to_sym]
+                        end
       ts_add_scope
     end
 
     def ts_add_scope
       class_eval do
         scope ts_scope_method, ->(value) do
-          resulting_ids = ts_search(value).map(&:id)
+          resulting_ids = ts_search(value).rows.map { |row| row[0] }
           where(id: resulting_ids)
         end
       end
@@ -51,8 +55,16 @@ module PgSearchable
 
     def ts_search(value)
       return if @ts_search_fields.blank? || value.blank?
-      includes(@ts_joins).references(:all).where(
-        TextToSqlQuery.new(value, @ts_search_fields, @default_field, @ts_search_fields_mappings).where_clause).distinct
+      sql_query_object = TextToSqlQuery.new(
+        value,
+        @ts_search_fields,
+        @default_fields,
+        @ts_search_fields_mappings,
+        @ts_joins
+      )
+      sql_query = select(:id).distinct.joins(sql_query_object.join_clause).group(:id).having(sql_query_object.where_clause)
+      modified_sql_query = sql_query.to_sql.gsub('INNER', 'LEFT OUTER')
+      ActiveRecord::Base.connection.exec_query(modified_sql_query)
     end
 
     def should_update_cache_field?
diff --git a/lib/text_to_sql_query.rb b/lib/text_to_sql_query.rb
index c464349..cd63baf 100644
--- a/lib/text_to_sql_query.rb
+++ b/lib/text_to_sql_query.rb
@@ -1,10 +1,17 @@
 require_relative 'parser'
 
 class TextToSqlQuery
-  def initialize(text, fields, default_field, fields_mappings = {})
+  def initialize(text, fields, default_fields, fields_mappings = {}, joins = [])
     @text = text.to_s.strip
     @fields = fields.map(&:to_sym)
-    @default_field = default_field.to_sym
+
+    # Keep compatibility with previous version where default_field(s) was string/symbol
+    @default_fields = if default_fields.is_a? Array
+                        default_fields.map(&:to_sym)
+                      else
+                        [default_fields.to_sym]
+                      end
+
     @fields_mappings = fields_mappings.merge(@fields.reduce({}) do |mappings, field|
       _table_name, field_name = field.to_s.split('.')
       mappings[field_name.to_sym] = field
@@ -13,6 +20,7 @@ class TextToSqlQuery
     fields_mappings.each do |field, value|
       @fields_mappings[field] = value if @fields_mappings[field]
     end
+    @joins = joins
   end
 
   def where_clause
@@ -21,7 +29,12 @@ class TextToSqlQuery
     generate_sql @parsed_tree
   end
 
-  private
+  def join_clause
+    return nil if @joins.empty?
+    return *@joins
+  end
+
+private
 
   def generate_sql(tree)
     first_key = tree.keys.first
@@ -29,7 +42,14 @@ class TextToSqlQuery
     case first_key
     when :DEFAULT_COLUMN
       escaped_node_value = handle_special_chars node_value
-      ["CAST(#{@default_field.to_s} AS TEXT) ILIKE ?", "%#{escaped_node_value}%"]
+      query_part = '('
+      params_part = []
+      @default_fields.each do |default_field|
+        query_part += "CAST(#{default_field.to_s} AS TEXT) ILIKE ? OR "
+        params_part << "%#{escaped_node_value}%"
+      end
+      query_part = query_part[0...-4] + ')'
+      [query_part, *params_part]
     when :OPERATOR_OR
       generate_expression_for_logical_operator(:OR, node_value)
     when :OPERATOR_AND
@@ -53,7 +73,7 @@ class TextToSqlQuery
       if mapping.nil?
         raise "Unknown field '#{first_key.to_s}'"
       else
-        ["CAST(#{mapping.to_s} AS TEXT) ILIKE ?", "%#{escaped_node_value}%"]
+        ["STRING_AGG(CAST(#{mapping.to_s} AS TEXT), '') ILIKE ?", "%#{escaped_node_value}%"]
       end
     end
   end
@@ -88,6 +108,7 @@ class TextToSqlQuery
     result.gsub!(/\_/, '\_')
     result.tr!('\\', '\\')
     result.gsub!(/%/, '\%')
+    result.downcase!
     result
   end
 end
diff --git a/spec/lib/pg_searchable_new_spec.rb b/spec/lib/pg_searchable_new_spec.rb
index 2bf7fd6..01f9204 100644
--- a/spec/lib/pg_searchable_new_spec.rb
+++ b/spec/lib/pg_searchable_new_spec.rb
@@ -47,6 +47,20 @@ describe PgSearchable do
         expect(VectorModel.scope_search("#{record2.id}")).to contain_exactly(record2)
       end
 
+      it 'can search multiple default columns if no column name is used with single search term' do
+        records = VectorModelWithTwoDefaultColumns.create [{ name: 'hamo', value: '5' }, { name: 'meho', value: '20 hamo' }, { name: 'munja-5', value: '300' }]
+
+        expect(VectorModelWithTwoDefaultColumns.scope_search('name:hamo')).to contain_exactly(records[0])
+        expect(VectorModelWithTwoDefaultColumns.scope_search('hamo')).to contain_exactly(records[0], records[1])
+        expect(VectorModelWithTwoDefaultColumns.scope_search('5')).to contain_exactly(records[0], records[2])
+      end
+
+      it 'can search multiple default columns if no column name is used in query containing multiple search terms' do
+        records = VectorModelWithTwoDefaultColumns.create [{ name: 'hamo', value: '9' }, { name: 'meho', value: '5' }, { name: 'oko-9', value: '100' }]
+
+        expect(VectorModelWithTwoDefaultColumns.scope_search('(9 and not name:hamo) or meho')).to contain_exactly(records[2], records[1])
+      end
+
       it 'searches column declared in search term' do
         record1 = VectorModel.create name: 'hamo', value: '-45'
         record2 = VectorModel.create name: 'meho', value: '120'
@@ -144,37 +158,211 @@ describe PgSearchable do
         expect(DynamicModelWithTagValues.scope_search('tag:green or value:"not"')).to contain_exactly(record1, record2)
       end
 
+      it 'can search for search term containing INNER word' do
+        records = DynamicModelWithTagValues.create [{ name: 'inner', value: 'amazing' },
+                                                    { name: 'new record', value: 'INNER' }]
 
+        Tag.create [{ taggable: records[0], value: 'red', custom_attribute: 'rose' },
+                    { taggable: records[1], value: 'INNER', custom_attribute: 'garden' }]
 
-      it 'can search in referenced column and in model columns with multiple search terms connected with logical operators' do
-        record1 = DynamicModelWithTagValues.create name: 'something', value: 'amazing'
-        record2 = DynamicModelWithTagValues.create name: 'new record', value: 'not so amazing'
-        record3 = DynamicModelWithTagValues.create name: 'last one', value: 'no value'
-        record4 = DynamicModelWithTagValues.create name: 'really last one', value: 'no value'
-        Tag.create(taggable: record1, value: 'red')
-        Tag.create(taggable: record1, value: 'green')
-        Tag.create(taggable: record2, value: 'black')
-        Tag.create(taggable: record3, value: '-12')
-        Tag.create(taggable: record4, value: '-')
-
-        expect(DynamicModelWithTagValues.scope_search('tag:red or tag:black')).to contain_exactly(record1, record2)
-        expect(DynamicModelWithTagValues.scope_search('tag:red and tag:black')).to be_empty
-        expect(DynamicModelWithTagValues.scope_search('tag:red or tag:green')).to contain_exactly(record1)
-        expect(DynamicModelWithTagValues.scope_search('not tag:-12 and not value:amazing')).to contain_exactly(record4)
+        expect(DynamicModelWithTagValues.scope_search('name:inner')).to contain_exactly(records[0])
+        expect(DynamicModelWithTagValues.scope_search('value:INNER')).to contain_exactly(records[1])
+        expect(DynamicModelWithTagValues.scope_search('tag:inner')).to contain_exactly(records[1])
+        expect(DynamicModelWithTagValues.scope_search('tag:INNER')).to contain_exactly(records[1])
       end
 
-      it 'can search in referenced column and in model columns with multiple search terms connected with logical operators and with brackets' do
-        record1 = DynamicModelWithTagValues.create name: 'something', value: 'amazing'
-        record2 = DynamicModelWithTagValues.create name: 'new record', value: 'not so amazing'
-        record3 = DynamicModelWithTagValues.create name: 'last one', value: 'no value'
-        record4 = DynamicModelWithTagValues.create name: 'really last one', value: 'no value'
-        Tag.create(taggable: record1, value: 'red')
-        Tag.create(taggable: record1, value: 'green')
-        Tag.create(taggable: record2, value: 'black')
-        Tag.create(taggable: record3, value: '-12')
-        Tag.create(taggable: record4, value: '-')
+      describe 'searching in model with has_many association' do
+        before do
+          records = DynamicModelWithTagValues.create [{ name: 'something', value: 'amazing' },
+                                                      { name: 'new record', value: 'not so amazing' },
+                                                      { name: 'last one', value: 'no value' },
+                                                      { name: 'really last one', value: 'no value' }]
 
-        expect(DynamicModelWithTagValues.scope_search('(tag:- and not tag:12) or (value:"amazing" and not value:"not")')).to contain_exactly(record1, record4)
+          Tag.create [{ taggable: records[0], value: 'red', custom_attribute: 'rose' },
+                      { taggable: records[0], value: 'green', custom_attribute: 'garden' },
+                      { taggable: records[1], value: 'black', custom_attribute: 'sky' },
+                      { taggable: records[2], value: '-1/12', custom_attribute: 'gold nugget' },
+                      { taggable: records[3], value: '-', custom_attribute: 'unknown' },
+                      { taggable: records[3], value: 'red-green', custom_attribute: 'unicorn' }]
+        end
+
+        it 'can search with multiple search terms connected with OR operator' do
+          records = DynamicModelWithTagValues.all
+
+          expect(DynamicModelWithTagValues.scope_search('tag:red or tag:black')).to contain_exactly(records[0], records[1], records[3])
+          expect(DynamicModelWithTagValues.scope_search('tag:red or tag:green')).to contain_exactly(records[0], records[3])
+        end
+
+        it 'can search with multiple search terms connected with AND operator' do
+          records = DynamicModelWithTagValues.all
+
+          expect(DynamicModelWithTagValues.scope_search('tag:red and tag:black')).to be_empty
+          expect(DynamicModelWithTagValues.scope_search('tag:red and tag:green')).to contain_exactly(records[0], records[3])
+        end
+
+        it 'can search with multiple search terms and containing NOT' do
+          records = DynamicModelWithTagValues.all
+
+          expect(DynamicModelWithTagValues.scope_search('not tag:"-1/12" and not value:amazing')).to contain_exactly(records[3])
+        end
+
+        it 'can search in referenced column and in model columns with multiple search terms connected with logical operators and with brackets' do
+          records = DynamicModelWithTagValues.all
+
+          expect(DynamicModelWithTagValues.scope_search('(tag:- and not tag:12) or (value:"amazing" and not value:"not")')).to contain_exactly(records[0], records[3])
+        end
+      end
+
+      describe 'searching through multiple referenced columns in model with has_many association' do
+        before do
+          records = DynamicModelWithTagValuesAndCustomAttribute.create [{ name: 'something', value: 'amazing' },
+                                                                        { name: 'new record', value: 'not so amazing' },
+                                                                        { name: 'last one', value: 'no value' },
+                                                                        { name: 'really last one', value: 'no value' }]
+
+          Tag.create [{ taggable: records[0], value: 'red', custom_attribute: 'rose' },
+                      { taggable: records[0], value: 'green', custom_attribute: 'garden' },
+                      { taggable: records[1], value: 'black', custom_attribute: 'sky' },
+                      { taggable: records[2], value: '-1/12', custom_attribute: 'gold nugget' },
+                      { taggable: records[3], value: '-', custom_attribute: 'unknown' },
+                      { taggable: records[3], value: 'red-green', custom_attribute: 'unicorn' }]
+        end
+
+        it 'can search with multiple search terms connected with OR operator' do
+          records = DynamicModelWithTagValuesAndCustomAttribute.all
+
+          expect(DynamicModelWithTagValuesAndCustomAttribute.scope_search('tag:red or custom:sky')).to contain_exactly(records[0], records[1], records[3])
+        end
+
+        it 'can search with multiple search terms connected with AND operator' do
+          records = DynamicModelWithTagValuesAndCustomAttribute.all
+
+          expect(DynamicModelWithTagValuesAndCustomAttribute.scope_search('custom:unicorn and tag:black')).to be_empty
+          expect(DynamicModelWithTagValuesAndCustomAttribute.scope_search('tag:"-1/12" and custom:gold')).to contain_exactly(records[2])
+        end
+
+        it 'can search with multiple search terms and containing NOT' do
+          expect(DynamicModelWithTagValuesAndCustomAttribute.scope_search('not tag:"-1/12" and not value:amazing and not custom:unknown')).to be_empty
+        end
+
+        it 'can search with multiple search terms connected with logical operators and with brackets' do
+          records = DynamicModelWithTagValuesAndCustomAttribute.all
+
+          expect(DynamicModelWithTagValuesAndCustomAttribute.scope_search('(tag:- and not tag:12) or (value:"amazing" and not value:"not") or (custom:unknown or custom:rose)')).to contain_exactly(records[0], records[3])
+        end
+      end
+
+      describe 'searching in model with multiple has_many associations' do
+        before do
+          records = DynamicModelWithTagAndCategories.create [{ name: 'something', value: 'amazing' },
+                                                             { name: 'new record', value: 'not so amazing' },
+                                                             { name: 'last one', value: 'no value' },
+                                                             { name: 'really last one', value: 'no value' }]
+
+          Tag.create [{ taggable: records[0], value: 'red', custom_attribute: 'rose' },
+                      { taggable: records[0], value: 'green', custom_attribute: 'garden' },
+                      { taggable: records[1], value: 'black', custom_attribute: 'sky' },
+                      { taggable: records[2], value: '-1/12', custom_attribute: 'gold nugget' },
+                      { taggable: records[3], value: '-', custom_attribute: 'unknown' },
+                      { taggable: records[3], value: 'red-green', custom_attribute: 'unicorn' }]
+
+          Category.create [{ categoriable: records[0], name: 'home' },
+                           { categoriable: records[0], name: 'home' },
+                           { categoriable: records[1], name: 'world' },
+                           { categoriable: records[2], name: 'math' },
+                           { categoriable: records[3], name: 'unknown' },
+                           { categoriable: records[3], name: 'myth' }]
+
+        end
+
+        it 'can search with multiple search terms connected with OR operator' do
+          records = DynamicModelWithTagAndCategories.all
+
+          expect(DynamicModelWithTagAndCategories.scope_search('tag:red or category:math')).to contain_exactly(records[0], records[2], records[3])
+        end
+
+        it 'can search with multiple search terms connected with AND operator' do
+          records = DynamicModelWithTagAndCategories.all
+
+          expect(DynamicModelWithTagAndCategories.scope_search('category:home and tag:-')).to be_empty
+          expect(DynamicModelWithTagAndCategories.scope_search('tag:"-1/12" and category:math')).to contain_exactly(records[2])
+        end
+
+        it 'can search with multiple search terms and containing NOT' do
+          expect(DynamicModelWithTagAndCategories.scope_search('not tag:"-1/12" and not value:amazing and not category:unknown')).to be_empty
+        end
+
+        it 'can search with multiple search terms connected with logical operators and with brackets' do
+          records = DynamicModelWithTagAndCategories.all
+
+          expect(DynamicModelWithTagAndCategories.scope_search('(tag:- and not tag:12) or (value:"amazing" and not value:"not") or (category:unknown or category:math)')).to contain_exactly(records[0], records[2], records[3])
+        end
+      end
+
+      describe 'joins with through association' do
+        let(:players) { Player.all }
+
+        before do
+          players = Player.create([{ name: 'first', value: 'downtown' },
+                                   { name: 'redliner', value: 'uptown' },
+                                   { name: 'flying', value: 'eagle' },
+                                   { name: 'blue', value: 'marine' }])
+
+
+          ptags = Ptag.create [{ value: 'e-ink' },
+                               { value: 'black&white' },
+                               { value: 'rich' },
+                               { value: 'grayscale' },
+                               { value: 'LED' }]
+
+          players[0].ptags << ptags[0..1]
+          players[1].ptags << ptags[0..2]
+          players[2].ptags << ptags[2..3]
+          players[3].ptags << ptags[4]
+        end
+
+        it 'can search in default column of model with through association' do
+          expect(Player.scope_search('l and not y and not blue')).to contain_exactly(players[1])
+        end
+
+        it 'can search in referenced column associated with through relation - simple search' do
+          expect(Player.scope_search('tag:e-ink')).to contain_exactly(players[0], players[1])
+        end
+
+        it 'can search in referenced column associated with through relaction - simple search with OR operator' do
+          expect(Player.scope_search('tag:e-ink OR tag:rich')).to contain_exactly(players[0], players[1], players[2])
+        end
+
+        it 'can search in referenced column associated with through relaction - simple search with AND operator' do
+          expect(Player.scope_search('tag:e-ink AND tag:rich')).to contain_exactly(players[1])
+        end
+
+        it 'can search in referenced column associated with through relaction - simple search with NOT operator' do
+          expect(Player.scope_search('NOT tag:e-ink')).to contain_exactly(players[2], players[3])
+        end
+
+        it 'can search in referenced column associated with through relaction - mixed search terms with OR' do
+          expect(Player.scope_search('tag:e-ink OR blue')).to contain_exactly(players[0], players[1], players[3])
+        end
+
+        it 'can search in referenced column associated with through relaction - mixed search terms with AND' do
+          expect(Player.scope_search('tag:e-ink AND first')).to contain_exactly(players[0])
+        end
+
+        it 'can search in referenced column associated with through relaction - mixed search terms with OR NOT' do
+          expect(Player.scope_search('tag:led OR NOT first')).to contain_exactly(players[1], players[2], players[3])
+        end
+
+        it 'can search in referenced column associated with through relaction - mixed search terms with AND NOT' do
+          expect(Player.scope_search('tag:e-ink AND NOT first')).to contain_exactly(players[1])
+        end
+
+        it 'can search in referenced column and in model columns - complex search' do
+          expect(Player.scope_search('(tag:e-ink AND tag:rich) OR (blue or value:eagle)')).to contain_exactly(players[1], players[2], players[3])
+          expect(Player.scope_search('tag:e-ink AND tag:rich AND NOT tag:black')).to be_empty
+          expect(Player.scope_search('name:l AND (value:uptown or value:marine) AND (tag:e-ink and tag:rich)')).to contain_exactly(players[1])
+          expect(Player.scope_search('name:l AND (value:uptown or value:marine) AND (tag:e-ink and tag:led)')).to be_empty
+        end
       end
     end
   end
diff --git a/spec/lib/text_to_sql_query_spec.rb b/spec/lib/text_to_sql_query_spec.rb
index aed9c6b..5a1016d 100644
--- a/spec/lib/text_to_sql_query_spec.rb
+++ b/spec/lib/text_to_sql_query_spec.rb
@@ -4,63 +4,75 @@ require_relative '../../lib/text_to_sql_query'
 describe TextToSqlQuery do
   describe '.new' do
     # tests simple search term without column name and without quotes
-    it { expect(described_class.new('some-default-value', [:"players.name"], :"players.name").where_clause).to eq(['CAST(players.name AS TEXT) ILIKE ?', '%some-default-value%']) }
+    it { expect(described_class.new('some-default-value', [:"players.name"], :"players.name").where_clause).to eq(['(CAST(players.name AS TEXT) ILIKE ?)', '%some-default-value%']) }
+
+    # tests simple search with two default columns without quotes
+    it { expect(described_class.new('search-term', [:'players.name', :'players.tags', 'players.id'], [:'players.name', :'players.tags']).where_clause).to eq(['(CAST(players.name AS TEXT) ILIKE ? OR CAST(players.tags AS TEXT) ILIKE ?)', '%search-term%', '%search-term%']) }
+
+    # tests simple search with two default columns with quotes
+    it { expect(described_class.new('"search-term"', [:'players.name', :'players.tags', 'players.id'], [:'players.name', :'players.tags']).where_clause).to eq(['(CAST(players.name AS TEXT) ILIKE ? OR CAST(players.tags AS TEXT) ILIKE ?)', '%search-term%', '%search-term%']) }
+
+    # tests simple search with three default columns without quotes
+    it { expect(described_class.new('search-term', [:'players.name', :'players.tags', 'players.id'], [:'players.name', :'players.tags', :'players.id']).where_clause).to eq(['(CAST(players.name AS TEXT) ILIKE ? OR CAST(players.tags AS TEXT) ILIKE ? OR CAST(players.id AS TEXT) ILIKE ?)', '%search-term%', '%search-term%', '%search-term%']) }
 
     # tests simple search term with column name and without quotes
-    it { expect(described_class.new('name:ab', [:"players.name"], :"players.name").where_clause).to eq(['CAST(players.name AS TEXT) ILIKE ?', '%ab%']) }
+    it { expect(described_class.new('name:ab', [:"players.name"], :"players.name").where_clause).to eq(["STRING_AGG(CAST(players.name AS TEXT), '') ILIKE ?", '%ab%']) }
 
     # tests simple search term with unknown column name and without quotes
     it { expect{described_class.new('unknown:ab', [:"players.name"], :"players.name").where_clause}.to raise_error(RuntimeError, "Unknown field 'unknown'") }
 
     # tests simple search term without column name and with quotes
-    it { expect(described_class.new('"ab"', [:"players.name", :"players.device_id"],  :"players.device_id").where_clause).to eq(["CAST(players.device_id AS TEXT) ILIKE ?", "%ab%"]) }
+    it { expect(described_class.new('"ab"', [:"players.name", :"players.device_id"],  :"players.device_id").where_clause).to eq(["(CAST(players.device_id AS TEXT) ILIKE ?)", "%ab%"]) }
 
     # tests simple search term with column name and with quotes
-    it { expect(described_class.new('tags:"ab"', [:"players.name", :"players.tags"],  :"players.device_id").where_clause).to eq(["CAST(players.tags AS TEXT) ILIKE ?", "%ab%"]) }
+    it { expect(described_class.new('tags:"ab"', [:"players.name", :"players.tags"],  :"players.device_id").where_clause).to eq(["STRING_AGG(CAST(players.tags AS TEXT), '') ILIKE ?", "%ab%"]) }
 
     # tests search without operators
-    it { expect(described_class.new('123 456', [:"players.name", :"players.device_id"],  :"players.device_id").where_clause).to eq(["(CAST(players.device_id AS TEXT) ILIKE ? OR CAST(players.device_id AS TEXT) ILIKE ?)", "%123%", "%456%"]) }
+    it { expect(described_class.new('123 456', [:"players.name", :"players.device_id"],  :"players.device_id").where_clause).to eq(["((CAST(players.device_id AS TEXT) ILIKE ?) OR (CAST(players.device_id AS TEXT) ILIKE ?))", "%123%", "%456%"]) }
 
     # tests search with OR operator
-    it { expect(described_class.new('123 or 456', [:"players.name", :"players.device_id"],  :"players.device_id").where_clause).to eq(["(CAST(players.device_id AS TEXT) ILIKE ? OR CAST(players.device_id AS TEXT) ILIKE ?)", "%123%", "%456%"]) }
+    it { expect(described_class.new('123 or 456', [:"players.name", :"players.device_id"],  :"players.device_id").where_clause).to eq(["((CAST(players.device_id AS TEXT) ILIKE ?) OR (CAST(players.device_id AS TEXT) ILIKE ?))", "%123%", "%456%"]) }
 
     # tests search with AND operator
-    it { expect(described_class.new('123 and 456', [:"players.name", :"players.device_id"],  :"players.device_id").where_clause).to eq(["(CAST(players.device_id AS TEXT) ILIKE ? AND CAST(players.device_id AS TEXT) ILIKE ?)", "%123%", "%456%"]) }
+    it { expect(described_class.new('123 and 456', [:"players.name", :"players.device_id"],  :"players.device_id").where_clause).to eq(["((CAST(players.device_id AS TEXT) ILIKE ?) AND (CAST(players.device_id AS TEXT) ILIKE ?))", "%123%", "%456%"]) }
 
     # tests search with NOT operator on default column
-    it { expect(described_class.new('not 23', [:"players.name", :"players.device_id"],  :"players.device_id").where_clause).to eq(["NOT CAST(players.device_id AS TEXT) ILIKE ?", "%23%"]) }
+    it { expect(described_class.new('not 23', [:"players.name", :"players.device_id"],  :"players.device_id").where_clause).to eq(["NOT (CAST(players.device_id AS TEXT) ILIKE ?)", "%23%"]) }
 
     # tests search with NOT operator on non-default column
-    it { expect(described_class.new('not value:23', [:"players.name", :"players.value"],  :"players.device_id").where_clause).to eq(["NOT CAST(players.value AS TEXT) ILIKE ?", "%23%"]) }
+    it { expect(described_class.new('not value:23', [:"players.name", :"players.value"],  :"players.device_id").where_clause).to eq(["NOT STRING_AGG(CAST(players.value AS TEXT), '') ILIKE ?", "%23%"]) }
 
     # tests search with mixed logical operators
-    it { expect(described_class.new('name:ab and not value:hf-1', [:"players.name", :"players.value"],  :"players.device_id").where_clause).to eq(['(CAST(players.name AS TEXT) ILIKE ? AND NOT CAST(players.value AS TEXT) ILIKE ?)', '%ab%', '%hf-1%']) }
+    it { expect(described_class.new('name:ab and not value:hf-1', [:"players.name", :"players.value"],  :"players.device_id").where_clause).to eq(["(STRING_AGG(CAST(players.name AS TEXT), '') ILIKE ? AND NOT STRING_AGG(CAST(players.value AS TEXT), '') ILIKE ?)", '%ab%', '%hf-1%']) }
 
     # tests search with mixed logical operators without NOT'
-    it { expect(described_class.new('name:a and name:b or name:c', [:"players.name", :"players.value"],  :"players.device_id").where_clause).to eq(['((CAST(players.name AS TEXT) ILIKE ? AND CAST(players.name AS TEXT) ILIKE ?) OR CAST(players.name AS TEXT) ILIKE ?)', '%a%', '%b%', '%c%']) }
+    it { expect(described_class.new('name:a and name:b or name:c', [:"players.name", :"players.value"],  :"players.device_id").where_clause).to eq(["((STRING_AGG(CAST(players.name AS TEXT), '') ILIKE ? AND STRING_AGG(CAST(players.name AS TEXT), '') ILIKE ?) OR STRING_AGG(CAST(players.name AS TEXT), '') ILIKE ?)", '%a%', '%b%', '%c%']) }
 
     # tests search with brackets in expression
-    it { expect(described_class.new('name:a and (name:b or name:c)', [:"players.name", :"players.value"],  :"players.device_id").where_clause).to eq(['(CAST(players.name AS TEXT) ILIKE ? AND (CAST(players.name AS TEXT) ILIKE ? OR CAST(players.name AS TEXT) ILIKE ?))', '%a%', '%b%', '%c%']) }
+    it { expect(described_class.new('name:a and (name:b or name:c)', [:"players.name", :"players.value"],  :"players.device_id").where_clause).to eq(["(STRING_AGG(CAST(players.name AS TEXT), '') ILIKE ? AND (STRING_AGG(CAST(players.name AS TEXT), '') ILIKE ? OR STRING_AGG(CAST(players.name AS TEXT), '') ILIKE ?))", '%a%', '%b%', '%c%']) }
 
     # tests search with brackets in expression and with NOT operator
-    it { expect(described_class.new('name:a and not (name:b or name:c)', [:"players.name", :"players.value"],  :"players.device_id").where_clause).to eq(['(CAST(players.name AS TEXT) ILIKE ? AND NOT (CAST(players.name AS TEXT) ILIKE ? OR CAST(players.name AS TEXT) ILIKE ?))', '%a%', '%b%', '%c%']) }
+    it { expect(described_class.new('name:a and not (name:b or name:c)', [:"players.name", :"players.value"],  :"players.device_id").where_clause).to eq(["(STRING_AGG(CAST(players.name AS TEXT), '') ILIKE ? AND NOT (STRING_AGG(CAST(players.name AS TEXT), '') ILIKE ? OR STRING_AGG(CAST(players.name AS TEXT), '') ILIKE ?))", '%a%', '%b%', '%c%']) }
 
     # tests search with special characters in search term
-    it { expect(described_class.new('name:"%a_\"', [:"players.name", :"players.value"],  :"players.device_id").where_clause).to eq(['CAST(players.name AS TEXT) ILIKE ?', '%\%a\_\\%']) }
+    it { expect(described_class.new('name:"%a_\"', [:"players.name", :"players.value"],  :"players.device_id").where_clause).to eq(["STRING_AGG(CAST(players.name AS TEXT), '') ILIKE ?", '%\%a\_\\%']) }
 
     # tests search with field mappings
-    it { expect(described_class.new('tags:h1-r', [:'players.name', :'players.value', :'players.device_id'],  :"players.device_id", { tags: "tags.value" }).where_clause).to eq(['CAST(tags.value AS TEXT) ILIKE ?', '%h1-r%']) }
+    it { expect(described_class.new('tags:h1-r', [:'players.name', :'players.value', :'players.device_id'],  :"players.device_id", { tags: "tags.value" }).where_clause).to eq(["STRING_AGG(CAST(tags.value AS TEXT), '') ILIKE ?", '%h1-r%']) }
 
     # tests search with field mappings when fields array has same mapping
-    it { expect(described_class.new('tags:h1-r', [:'players.name', :'players.tags', :'players.device_id'],  :"players.device_id", { tags: "tags.value" }).where_clause).to eq(["CAST(tags.value AS TEXT) ILIKE ?", "%h1-r%"]) }
+    it { expect(described_class.new('tags:h1-r', [:'players.name', :'players.tags', :'players.device_id'],  :"players.device_id", { tags: "tags.value" }).where_clause).to eq(["STRING_AGG(CAST(tags.value AS TEXT), '') ILIKE ?", "%h1-r%"]) }
 
     # tests complex query
-    it { expect(described_class.new('(device_id:"with space" tags:mta no-quotes-id-123) or "id with quotes-5"  and   ( ("id with q 10" or "id with q 20") and ("id with Q 30" "id with Q 40") and not id-without-Q-50)', [:'players.name', :'players.value', :'players.device_id'],  :"players.device_id", { tags: 'tags.name' }).where_clause).to eq(['((CAST(players.device_id AS TEXT) ILIKE ? OR (CAST(tags.name AS TEXT) ILIKE ? OR CAST(players.device_id AS TEXT) ILIKE ?)) OR (CAST(players.device_id AS TEXT) ILIKE ? AND (((CAST(players.device_id AS TEXT) ILIKE ? OR CAST(players.device_id AS TEXT) ILIKE ?) AND (CAST(players.device_id AS TEXT) ILIKE ? OR CAST(players.device_id AS TEXT) ILIKE ?)) AND NOT CAST(players.device_id AS TEXT) ILIKE ?)))', '%with space%', '%mta%', '%no-quotes-id-123%', '%id with quotes-5%', '%id with q 10%', '%id with q 20%', '%id with Q 30%', '%id with Q 40%', '%id-without-Q-50%']) }
+    it { expect(described_class.new('(device_id:"with space" tags:mta no-quotes-id-123) or "id with quotes-5"  and   ( ("id with q 10" or "id with q 20") and ("id with Q 30" "id with Q 40") and not id-without-Q-50)', [:'players.name', :'players.value', :'players.device_id'],  :"players.device_id", { tags: 'tags.name' }).where_clause).to eq(["((STRING_AGG(CAST(players.device_id AS TEXT), '') ILIKE ? OR (STRING_AGG(CAST(tags.name AS TEXT), '') ILIKE ? OR (CAST(players.device_id AS TEXT) ILIKE ?))) OR ((CAST(players.device_id AS TEXT) ILIKE ?) AND ((((CAST(players.device_id AS TEXT) ILIKE ?) OR (CAST(players.device_id AS TEXT) ILIKE ?)) AND ((CAST(players.device_id AS TEXT) ILIKE ?) OR (CAST(players.device_id AS TEXT) ILIKE ?))) AND NOT (CAST(players.device_id AS TEXT) ILIKE ?))))", '%with space%', '%mta%', '%no-quotes-id-123%', '%id with quotes-5%', '%id with q 10%', '%id with q 20%', '%id with q 30%', '%id with q 40%', '%id-without-q-50%']) }
+
+    # tests mixed query with and without column names and with multiple default columns
+    it { expect(described_class.new('("green hunter" and device_id:100) or ("blue bird" and not device_id:200)', [:'players.name', :'players.value', :'players.device_id'],  [:"players.name", :"players.tags"]).where_clause).to eq(["(((CAST(players.name AS TEXT) ILIKE ? OR CAST(players.tags AS TEXT) ILIKE ?) AND STRING_AGG(CAST(players.device_id AS TEXT), '') ILIKE ?) OR ((CAST(players.name AS TEXT) ILIKE ? OR CAST(players.tags AS TEXT) ILIKE ?) AND NOT STRING_AGG(CAST(players.device_id AS TEXT), '') ILIKE ?))", '%green hunter%', '%green hunter%', '%100%', '%blue bird%', '%blue bird%', '%200%']) }
 
     # tests query with multiple search terms with mixed and-or-not after dash and underscore
-    it { expect(described_class.new('123-and-456 -or-2 -not_not_1', [:'players.title', :'players.tag', :'players.device_id'], :'players.device_id').where_clause).to eq(['(CAST(players.device_id AS TEXT) ILIKE ? OR (CAST(players.device_id AS TEXT) ILIKE ? OR CAST(players.device_id AS TEXT) ILIKE ?))', '%123-and-456%', '%-or-2%', '%-not\_not\_1%'])}
+    it { expect(described_class.new('123-and-456 -or-2 -not_not_1', [:'players.title', :'players.tag', :'players.device_id'], :'players.device_id').where_clause).to eq(['((CAST(players.device_id AS TEXT) ILIKE ?) OR ((CAST(players.device_id AS TEXT) ILIKE ?) OR (CAST(players.device_id AS TEXT) ILIKE ?)))', '%123-and-456%', '%-or-2%', '%-not\_not\_1%'])}
 
     # tests query with multiple search terms with mixed and-or-not after dash and underscore
-    it { expect(described_class.new('andrew or ornela', [:'players.title', :'players.tag', :'players.device_id'], :'players.device_id').where_clause).to eq(['(CAST(players.device_id AS TEXT) ILIKE ? OR CAST(players.device_id AS TEXT) ILIKE ?)', '%andrew%', '%ornela%'])}
+    it { expect(described_class.new('andrew or ornela', [:'players.title', :'players.tag', :'players.device_id'], :'players.device_id').where_clause).to eq(['((CAST(players.device_id AS TEXT) ILIKE ?) OR (CAST(players.device_id AS TEXT) ILIKE ?))', '%andrew%', '%ornela%'])}
   end
 end
diff --git a/spec/schema.rb b/spec/schema.rb
index 0ddb2b9..8c20819 100644
--- a/spec/schema.rb
+++ b/spec/schema.rb
@@ -27,6 +27,7 @@ ActiveRecord::Schema.define do
 
   create_table :tags, force: true do |t|
     t.string :value
+    t.string :custom_attribute
     t.references :category, index: true
     t.references :taggable, polymorphic: true, index: true
     t.timestamps null: false
@@ -34,6 +35,7 @@ ActiveRecord::Schema.define do
 
   create_table :categories, force: true do |t|
     t.string :name
+    t.references :categoriable, polymorphic: true, index: true
     t.timestamps null: false
   end
 
@@ -42,4 +44,19 @@ ActiveRecord::Schema.define do
     t.string :name
     t.timestamps null: false
   end
+
+  create_table :players, force: true do |t|
+    t.string :name
+    t.string :value
+    t.timestamps null: false
+  end
+
+  create_table :ptags, force: true do |t|
+    t.string :value
+  end
+
+  create_table :taggings, force: true do |t|
+    t.belongs_to :player
+    t.belongs_to :ptag
+  end
 end
diff --git a/spec/support/models.rb b/spec/support/models.rb
index 58d632c..721b80f 100755
--- a/spec/support/models.rb
+++ b/spec/support/models.rb
@@ -5,6 +5,12 @@ class VectorModel < ActiveRecord::Base
   pg_search fields: %i[vector_models.id vector_models.name vector_models.value], cache: :search_cache
 end
 
+class VectorModelWithTwoDefaultColumns < ActiveRecord::Base
+  self.table_name = :vector_models
+  include PgSearchable
+  pg_search fields: %i[vector_models.id vector_models.name vector_models.value], default_fields: %i[vector_models.name vector_models.value], cache: :search_cache
+end
+
 class VectorModelWithMappings < ActiveRecord::Base
   self.table_name = :vector_models
   include PgSearchable
@@ -76,6 +82,21 @@ class DynamicModelWithTagValues < ActiveRecord::Base
   has_many :tags, as: :taggable
 end
 
+class DynamicModelWithTagAndCategories < ActiveRecord::Base
+  self.table_name = :dynamic_models
+  include PgSearchable
+  pg_search fields: %i[dynamic_models.id dynamic_models.name dynamic_models.value], fields_mappings: {tag: 'tags.value', category: 'categories.name'}, joins: [:tags, :categories]
+  has_many :tags, as: :taggable
+  has_many :categories, as: :categoriable
+end
+
+class DynamicModelWithTagValuesAndCustomAttribute < ActiveRecord::Base
+  self.table_name = :dynamic_models
+  include PgSearchable
+  pg_search fields: %i[dynamic_models.id dynamic_models.name dynamic_models.value], fields_mappings: {tag: 'tags.value', custom: 'tags.custom_attribute'}, joins: [:tags]
+  has_many :tags, as: :taggable
+end
+
 class DynamicModelWithCategory < ActiveRecord::Base
   self.table_name = :dynamic_models
   include PgSearchable
@@ -106,4 +127,23 @@ end
 
 class Category < ActiveRecord::Base
   has_many :tags
+  belongs_to :categoriable, polymorphic: true
 end
+
+class Player < ActiveRecord::Base
+  include PgSearchable
+  pg_search fields: %i[players.id players.name players.value], default_fields: [:name], fields_mappings: { tag: 'ptags.value' }, joins: [:ptags]
+  has_many :taggings
+  has_many :ptags, through: :taggings
+end
+
+class Ptag < ActiveRecord::Base
+  self.table_name = :ptags
+  has_many :taggings
+  has_many :players, through: :taggings
+end
+
+class Tagging < ActiveRecord::Base
+  belongs_to :player
+  belongs_to :ptag
+end
\ No newline at end of file