Add not feature with tests

README.md

@@ -174,6 +174,19 @@ You can apply an `OR` on associations as well or even nested ones, there isn't m
 I suggest you though to take a look on the [tests](spec/tests/or_filter_spec.rb), cause the syntax gets a bit complex after a while ;)
 
 
+### NOT Filter
+You can apply an SQL `NOT` (for ActiveRecord 4+) using the following syntax:
+`{not: {name: 'Filippos', email: {ends_with: '@gmail.com'}}}`
+
+It will generate: `WHERE (NOT (users.name = 'Filippos')) AND (NOT (users.email LIKE '%@gmail.com'))`
+
+You can apply an `NOT` on associations as well or even nested ones, there isn't much limitation on that.
+I suggest you to also take a look on the [tests](spec/tests/not_filter_spec.rb).
+
+Also I should note that you need to add specific (partial) queries if you don't want
+to have performance issues on tables with millions of rows.
+
+
 ### Scopes
 **Filtering on scopes is not enabled by default**.
 

lib/active_hash_relation/column_filters.rb

@@ -2,15 +2,23 @@ module ActiveHashRelation::ColumnFilters
   def filter_integer(resource, column, table_name, param)
     if param.is_a? Array
       n_param = param.to_s.gsub("\"","'").gsub("[","").gsub("]","") #fix this!
-      return resource.where("#{table_name}.#{column} IN (#{n_param})")
+      if @is_not
+        return resource.where.not("#{table_name}.#{column} IN (#{n_param})")
+      else
+        return resource.where("#{table_name}.#{column} IN (#{n_param})")
+      end
     elsif param.is_a? Hash
       if !param[:null].nil?
         return null_filters(resource, table_name, column, param)
       else
         return apply_leq_geq_le_ge_filters(resource, table_name, column, param)
       end
     else
-      return resource.where("#{table_name}.#{column} = ?", param)
+      if @is_not
+        return resource.where.not("#{table_name}.#{column} = ?", param)
+      else
+        return resource.where("#{table_name}.#{column} = ?", param)
+      end
     end
   end
 
@@ -25,15 +33,23 @@ def filter_decimal(resource, column, table_name, param)
   def filter_string(resource, column, table_name, param)
     if param.is_a? Array
       n_param = param.to_s.gsub("\"","'").gsub("[","").gsub("]","") #fix this!
-      return resource.where("#{table_name}.#{column} IN (#{n_param})")
+      if @is_not
+        return resource.where.not("#{table_name}.#{column} IN (#{n_param})")
+      else
+        return resource.where("#{table_name}.#{column} IN (#{n_param})")
+      end
     elsif param.is_a? Hash
       if !param[:null].nil?
         return null_filters(resource, table_name, column, param)
       else
         return apply_like_filters(resource, table_name, column, param)
       end
     else
-      return resource.where("#{table_name}.#{column} = ?", param)
+      if @is_not
+        return resource.where.not("#{table_name}.#{column} = ?", param)
+      else
+        return resource.where("#{table_name}.#{column} = ?", param)
+      end
     end
   end
 
@@ -44,15 +60,23 @@ def filter_text(resource, column, param)
   def filter_date(resource, column, table_name, param)
     if param.is_a? Array
       n_param = param.to_s.gsub("\"","'").gsub("[","").gsub("]","") #fix this!
-      return resource.where("#{table_name}.#{column} IN (#{n_param})")
+      if @is_not
+        return resource.where.not("#{table_name}.#{column} IN (#{n_param})")
+      else
+        return resource.where("#{table_name}.#{column} IN (#{n_param})")
+      end
     elsif param.is_a? Hash
       if !param[:null].nil?
         return null_filters(resource, table_name, column, param)
       else
         return apply_leq_geq_le_ge_filters(resource, table_name, column, param)
       end
     else
-      resource = resource.where(column => param)
+      if @is_not
+        resource = resource.where.not(column => param)
+      else
+        resource = resource.where(column => param)
+      end
     end
 
     return resource
@@ -61,15 +85,23 @@ def filter_date(resource, column, table_name, param)
   def filter_datetime(resource, column, table_name, param)
     if param.is_a? Array
       n_param = param.to_s.gsub("\"","'").gsub("[","").gsub("]","") #fix this!
-      return resource = resource.where("#{table_name}.#{column} IN (#{n_param})")
+      if @is_not
+        return resource = resource.where.not("#{table_name}.#{column} IN (#{n_param})")
+      else
+        return resource = resource.where("#{table_name}.#{column} IN (#{n_param})")
+      end
     elsif param.is_a? Hash
       if !param[:null].nil?
         return null_filters(resource, table_name, column, param)
       else
         return apply_leq_geq_le_ge_filters(resource, table_name, column, param)
       end
     else
-      resource = resource.where(column => param)
+      if @is_not
+        resource = resource.where.not(column => param)
+      else
+        resource = resource.where(column => param)
+      end
     end
 
     return resource
@@ -85,7 +117,11 @@ def filter_boolean(resource, column, table_name, param)
         b_param = ActiveRecord::Type::Boolean.new.type_cast_from_database(param)
       end
 
-      resource = resource.where(column => b_param)
+      if @is_not
+        resource = resource.where.not(column => b_param)
+      else
+        resource = resource.where(column => b_param)
+      end
     end
   end
 
@@ -95,15 +131,31 @@ def apply_leq_geq_le_ge_filters(resource, table_name, column, param)
     return resource.where("#{table_name}.#{column} = ?", param[:eq]) if param[:eq]
 
     if !param[:leq].blank?
-      resource = resource.where("#{table_name}.#{column} <= ?", param[:leq])
+      if @is_not
+        resource = resource.where.not("#{table_name}.#{column} <= ?", param[:leq])
+      else
+        resource = resource.where("#{table_name}.#{column} <= ?", param[:leq])
+      end
     elsif !param[:le].blank?
-      resource = resource.where("#{table_name}.#{column} < ?", param[:le])
+      if @is_not
+        resource = resource.where.not("#{table_name}.#{column} < ?", param[:le])
+      else
+        resource = resource.where("#{table_name}.#{column} < ?", param[:le])
+      end
     end
 
     if !param[:geq].blank?
-      resource = resource.where("#{table_name}.#{column} >= ?", param[:geq])
+      if @is_not
+        resource = resource.where.not("#{table_name}.#{column} >= ?", param[:geq])
+      else
+        resource = resource.where("#{table_name}.#{column} >= ?", param[:geq])
+      end
     elsif !param[:ge].blank?
-      resource = resource.where("#{table_name}.#{column} > ?", param[:ge])
+      if @is_not
+        resource = resource.where.not("#{table_name}.#{column} > ?", param[:ge])
+      else
+        resource = resource.where("#{table_name}.#{column} > ?", param[:ge])
+      end
     end
 
     return resource
@@ -114,31 +166,55 @@ def apply_like_filters(resource, table_name, column, param)
     like_method = "ILIKE" if param[:with_ilike]
 
     if !param[:starts_with].blank?
-      resource = resource.where("#{table_name}.#{column} #{like_method} ?", "#{param[:starts_with]}%")
+      if @is_not
+        resource = resource.where.not("#{table_name}.#{column} #{like_method} ?", "#{param[:starts_with]}%")
+      else
+        resource = resource.where("#{table_name}.#{column} #{like_method} ?", "#{param[:starts_with]}%")
+      end
     end
 
     if !param[:ends_with].blank?
-      resource = resource.where("#{table_name}.#{column} #{like_method} ?", "%#{param[:ends_with]}")
+      if @is_not
+        resource = resource.where.not("#{table_name}.#{column} #{like_method} ?", "%#{param[:ends_with]}")
+      else
+        resource = resource.where("#{table_name}.#{column} #{like_method} ?", "%#{param[:ends_with]}")
+      end
     end
 
     if !param[:like].blank?
-      resource = resource.where("#{table_name}.#{column} #{like_method} ?", "%#{param[:like]}%")
+      if @is_not
+        resource = resource.where.not("#{table_name}.#{column} #{like_method} ?", "%#{param[:like]}%")
+      else
+        resource = resource.where("#{table_name}.#{column} #{like_method} ?", "%#{param[:like]}%")
+      end
     end
 
     if !param[:eq].blank?
-      resource = resource.where("#{table_name}.#{column} = ?", param[:eq])
+      if @is_not
+        resource = resource.where.not("#{table_name}.#{column} = ?", param[:eq])
+      else
+        resource = resource.where("#{table_name}.#{column} = ?", param[:eq])
+      end
     end
 
     return resource
   end
 
   def null_filters(resource, table_name, column, param)
     if param[:null] == true
-      resource = resource.where("#{table_name}.#{column} IS NULL")
+      if @is_not
+        resource = resource.where.not("#{table_name}.#{column} IS NULL")
+      else
+        resource = resource.where("#{table_name}.#{column} IS NULL")
+      end
     end
 
     if param[:null] == false
-      resource = resource.where("#{table_name}.#{column} IS NOT NULL")
+      if @is_not
+        resource = resource.where.not("#{table_name}.#{column} IS NOT NULL")
+      else
+        resource = resource.where("#{table_name}.#{column} IS NOT NULL")
+      end
     end
 
     return resource

lib/active_hash_relation/filter_applier.rb

@@ -9,7 +9,7 @@ class FilterApplier
 
     attr_reader :configuration
 
-    def initialize(resource, params, include_associations: false, model: nil)
+    def initialize(resource, params, include_associations: false, model: nil, is_not: false)
       @configuration = Module.nesting.last.configuration
       @resource = resource
       if params.respond_to?(:to_unsafe_h)
@@ -19,10 +19,12 @@ def initialize(resource, params, include_associations: false, model: nil)
       end
       @include_associations = include_associations
       @model = find_model(model)
+      is_not ? @is_not = true : @is_not = false
     end
 
     def apply_filters
       run_or_filters
+      run_not_filters
 
       table_name = @model.table_name
       @model.columns.each do |c|
@@ -68,7 +70,7 @@ def filter_class(resource_name)
     def run_or_filters
       if @params[:or].is_a?(Array)
         if ActiveRecord::VERSION::MAJOR < 5
-          return Rails.logger.warn("OR query is supported on ActiveRecord 5+") 
+          return Rails.logger.warn("OR query is supported on ActiveRecord 5+")
         end
 
         if @params[:or].length >= 2
@@ -83,5 +85,16 @@ def run_or_filters
         end
       end
     end
+
+    def run_not_filters
+      if @params[:not].is_a?(Hash) && !@params[:not].blank?
+        @resource = self.class.new(
+          @resource,
+          @params[:not],
+          include_associations: @include_associations,
+          is_not: true
+        ).apply_filters
+      end
+    end
   end
 end

lib/active_hash_relation/version.rb

@@ -1,3 +1,3 @@
 module ActiveHashRelation
-  VERSION = "1.2.0"
+  VERSION = "1.3.0"
 end

spec/tests/not_filter_spec.rb

@@ -0,0 +1,105 @@
+describe ActiveHashRelation do
+  include Helpers
+
+  context 'NOT filter' do
+    it "one NOT clause" do
+      hash = {not: {name: 'Filippos'}}
+
+      query = HelperClass.new.apply_filters(User.all, hash).to_sql
+      expected_query = q(
+        "SELECT users.* FROM users WHERE (NOT (users.name = 'Filippos'))"
+      )
+
+      expect(strip(query)).to eq expected_query.to_s
+    end
+
+    it "multiple NOT clauses" do
+      hash = {not: {name: 'Filippos', email: '[email protected]'}}
+
+      query = HelperClass.new.apply_filters(User.all, hash).to_sql
+      expected_query = q(
+        "SELECT users.* FROM users WHERE",
+        "(NOT (users.name = 'Filippos'))",
+        "AND",
+        "(NOT (users.email = '[email protected]'))"
+      )
+
+      expect(strip(query)).to eq expected_query.to_s
+    end
+
+    if ActiveRecord::VERSION::MAJOR >= 5
+      it "NOT clause inside OR clause" do
+        hash = {or: [{not: {name: 'Filippos', token: '123'}}, {not: {name: 'Vasilis'}}]}
+
+        query = HelperClass.new.apply_filters(User.all, hash).to_sql
+        expected_query = q(
+          "SELECT users.* FROM users",
+          "WHERE",
+          "(",
+            "(NOT (users.name = 'Filippos')) AND (NOT (users.token = '123'))",
+            "OR",
+            "(NOT (users.name = 'Vasilis'))",
+          ")"
+        )
+
+        expect(strip(query)).to eq expected_query.to_s
+      end
+    end
+
+    it "complex NOT clause" do
+      hash = {not: {name: 'Filippos', email: {ends_with: '@gmail.com'}}}
+
+      query = HelperClass.new.apply_filters(User.all, hash).to_sql
+      expected_query = q(
+        "SELECT users.* FROM users",
+        "WHERE",
+        "(NOT (users.name = 'Filippos'))",
+        "AND",
+        "(NOT (users.email LIKE '%@gmail.com'))",
+      )
+
+      expect(strip(query)).to eq expected_query.to_s
+    end
+
+    context "on NULL" do
+      it "NOT clause on null" do
+        hash = {not: {name: {null: true}}}
+
+        query = HelperClass.new.apply_filters(User.all, hash).to_sql
+        expected_query = q(
+          "SELECT users.* FROM users WHERE (NOT (users.name IS NULL))"
+        )
+
+        expect(strip(query)).to eq expected_query.to_s
+      end
+
+      it "NOT clause on not null" do
+        hash = {not: {name: {null: false}}}
+
+        query = HelperClass.new.apply_filters(User.all, hash).to_sql
+        expected_query = q(
+          "SELECT users.* FROM users WHERE (NOT (users.name IS NOT NULL))"
+        )
+
+        expect(strip(query)).to eq expected_query.to_s
+      end
+    end
+
+    it "NOT clause on associations" do
+        hash = {microposts: {not: {content: 'Sveavägen 4', id: 1}}}
+
+        query = HelperClass.new.apply_filters(User.all, hash, include_associations: true).to_sql
+        expected_query = q(
+          "SELECT users.* FROM users",
+          "INNER JOIN microposts ON microposts.user_id = users.id",
+          "WHERE",
+          "(NOT (microposts.id = 1))",
+          "AND",
+          "(NOT (microposts.content = 'Sveavägen 4'))"
+        )
+
+        expect(strip(query)).to eq expected_query.to_s
+    end
+
+  end
+end