diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index e70ef9723d898..b853d87a9208f 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -155,7 +155,6 @@ def inherited(child_class) # :nodoc:
       end
 
       def find(*ids) # :nodoc:
-        # byebug
         # We don't have cache keys for this stuff yet
         return super unless ids.length == 1
         return super if block_given? ||
@@ -169,7 +168,6 @@ def find(*ids) # :nodoc:
 
         key = primary_key
 
-        # byebug
         statement = cached_find_by_statement(key) { |params|
           where(key => params.bind).limit(1)
         }
@@ -186,6 +184,7 @@ def find(*ids) # :nodoc:
       end
 
       def find_by(*args) # :nodoc:
+        # byebug
         return super if scope_attributes? || reflect_on_all_aggregations.any?
 
         hash = args.first
@@ -283,9 +282,7 @@ def cached_find_by_statement(key, &block)
         end
 
         def relation
-          # byebug
           relation = Relation.create(self)
-          # byebug
 
           if finder_needs_type_condition? && !ignore_default_scope?
             relation.where!(type_condition)
diff --git a/activerecord/lib/active_record/querying.rb b/activerecord/lib/active_record/querying.rb
index 60a55c3e25ba4..566785955549a 100644
--- a/activerecord/lib/active_record/querying.rb
+++ b/activerecord/lib/active_record/querying.rb
@@ -49,6 +49,14 @@ def find_by_sql(sql, binds = [], preparable: nil, &block)
         class_name: name
       }
 
+      # binds.each do 
+      #   column = ""
+      #   column = binds.first.name unless not binds.first.name
+      #   if self.attribute_names.include? column += "_aip"
+      #     # in this case the query was based on a column that has an _aip column and therefore purposes attached
+      #   end
+      # end
+
       message_bus.instrument("instantiation.active_record", payload) do
         result_set.map { |record| instantiate(record, column_types, &block) }
       end
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index 770d4cf48c663..23fb436e459d5 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -26,14 +26,13 @@ class Relation
     attr_reader :table, :klass, :loaded, :predicate_builder
     # ====================================
     # !!! Altered by prails
-    attr_accessor :skip_preloading_value, :purpose_fields, :for_purpose
+    attr_accessor :skip_preloading_value, :purpose_fields, :for_purpose, :query_columns
     # ====================================
     alias :model :klass
     alias :loaded? :loaded
     alias :locked? :lock_value
 
     def initialize(klass, table: klass.arel_table, predicate_builder: klass.predicate_builder, values: {})
-      # byebug
       @klass  = klass
       @table  = table
       @values = values
@@ -41,18 +40,18 @@ def initialize(klass, table: klass.arel_table, predicate_builder: klass.predicat
       @loaded = false
       @predicate_builder = predicate_builder
       @delegate_to_klass = false
-      @for_purpose = -1
 
       # ======================================================
       # !!! Added by prails
       # 
+      @for_purpose = -1
+      @query_columns = {}
       @purpose_fields = []
       @klass.attribute_names.each do |attribute|
         if attribute[-4..-1] == "_aip"
           @purpose_fields << attribute[0..-5]
         end
       end
-      # byebug
       # ======================================================
     end
 
@@ -246,15 +245,12 @@ def explain
 
     # Converts relation objects to Array.
     def to_ary
-      # byebug
       records.dup
     end
     alias to_a to_ary
 
     def records # :nodoc:
-      # byebug
       load
-      # byebug
 
       # ======================================================
       # !!! Added by prails
@@ -273,8 +269,12 @@ def records # :nodoc:
         end
       end
 
+
+
       # this sanitizes the attributs of the records themselves. This counts for normal relations and also for associations, if there are records left
       # checks each attribute's "_aip" field if the purpose is contained
+      records_to_delete = []
+
       if self.for_purpose and not self.purpose_fields.empty?
         @records.each do |record|
           record.attributes.each do |k,v|
@@ -290,13 +290,30 @@ def records # :nodoc:
               if not purposes.include? self.for_purpose
                 record[k] = nil
               end
+
+              if not self.query_columns.blank?
+                if self.query_columns.include? k.to_sym
+                  # in this case there was a query condition based on the columns present in @query_columns
+                  # find_by e.g. also uses this as well as .where() queries. 
+                  # If records where found based on this but the column was not allowed for the given purpose, we have to delete the whole record
+                  if not purposes.include? self.for_purpose
+                    records_to_delete << record
+                  end
+                end
+              end
+
             end
           end
         end
       end
-      # byebug
+      @records_dup = @records.dup
+      records_to_delete.each do |record|
+        @records_dup.delete(record)
+      end
 
-      @records
+      # byebug
+      # @records
+      @records_dup
     end
 
     # Serializes the relation objects Array.
diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index 32784452f44a2..f7613a187d25e 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -65,7 +65,6 @@ module FinderMethods
     #   Person.where(name: 'Spartacus', rating: 4).pluck(:field1, :field2)
     #   # returns an Array of the required fields.
     def find(*args)
-        # byebug
       return super if block_given?
       find_with_ids(*args)
     end
diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb
index 64e1c05cc22e7..3c77ceb442339 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -124,7 +124,11 @@ def for(*args)
       # byebug
       if args.size == 1
         # und gott sprach: es darf nur einen purpose geben
-        self.for_purpose = args.first
+        if args.first.is_a? Integer
+          self.for_purpose = args.first
+        else
+          raise ArgumentError, "purpose-ID must be of type Integer."
+        end
       else
         # hier unterschiedliche exceptions raisen, je nachdem ob keiner oder zu viele purposes angegeben wurden
         if args.size < 1
@@ -606,6 +610,17 @@ def left_outer_joins!(*args) # :nodoc:
     # If the condition is any blank-ish object, then #where is a no-op and returns
     # the current relation.
     def where(opts = :chain, *rest)
+      # byebug
+      # ===============================================================
+      # Added by Prails
+      # 
+      # ===============================================================
+      if not opts.blank?
+        self.query_columns = opts
+      end
+
+      # ===============================================================
+
       if :chain == opts
         WhereChain.new(spawn)
       elsif opts.blank?