diff --git a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
index cce8883076..f0c0fbab6c 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
@@ -61,17 +61,6 @@ module ActiveRecord
         lookup_cast_type(column.sql_type)
       end
 
-      def fetch_type_metadata(sql_type)
-        cast_type = lookup_cast_type(sql_type)
-        SqlTypeMetadata.new(
-          sql_type: sql_type,
-          type: cast_type.type,
-          limit: cast_type.limit,
-          precision: cast_type.precision,
-          scale: cast_type.scale,
-        )
-      end
-
       # Quotes a string, escaping any ' (single quote) and \ (backslash)
       # characters.
       def quote_string(s)
@@ -161,6 +150,10 @@ module ActiveRecord
       end
 
       private
+        def lookup_cast_type(sql_type)
+          type_map.lookup(sql_type)
+        end
+
         def id_value_for_database(value)
           if primary_key = value.class.primary_key
             value.instance_variable_get(:@attributes)[primary_key].value_for_database
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb
index c48a4acff8..a4fecc4a8e 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_creation.rb
@@ -133,5 +133,6 @@ module ActiveRecord
           end
       end
     end
+    SchemaCreation = AbstractAdapter::SchemaCreation # :nodoc:
   end
 end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index 1cc10e3b93..13629dee7f 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -976,16 +976,6 @@ module ActiveRecord
         foreign_key_for(from_table, options_or_to_table).present?
       end
 
-      def foreign_key_for(from_table, options_or_to_table = {}) # :nodoc:
-        return unless supports_foreign_keys?
-        foreign_keys(from_table).detect { |fk| fk.defined_for? options_or_to_table }
-      end
-
-      def foreign_key_for!(from_table, options_or_to_table = {}) # :nodoc:
-        foreign_key_for(from_table, options_or_to_table) || \
-          raise(ArgumentError, "Table '#{from_table}' has no foreign key for #{options_or_to_table}")
-      end
-
       def foreign_key_column_for(table_name) # :nodoc:
         prefix = Base.table_name_prefix
         suffix = Base.table_name_suffix
@@ -1005,19 +995,6 @@ module ActiveRecord
         insert_versions_sql(versions)
       end
 
-      def insert_versions_sql(versions) # :nodoc:
-        sm_table = quote_table_name(ActiveRecord::SchemaMigration.table_name)
-
-        if versions.is_a?(Array)
-          sql = "INSERT INTO #{sm_table} (version) VALUES\n"
-          sql << versions.map { |v| "(#{quote(v)})" }.join(",\n")
-          sql << ";\n\n"
-          sql
-        else
-          "INSERT INTO #{sm_table} (version) VALUES (#{quote(versions)});"
-        end
-      end
-
       def initialize_schema_migrations_table # :nodoc:
         ActiveRecord::SchemaMigration.create_table
       end
@@ -1263,6 +1240,10 @@ module ActiveRecord
           end
         end
 
+        def schema_creation
+          SchemaCreation.new(self)
+        end
+
         def create_table_definition(*args)
           TableDefinition.new(*args)
         end
@@ -1271,6 +1252,17 @@ module ActiveRecord
           AlterTable.new create_table_definition(name)
         end
 
+        def fetch_type_metadata(sql_type)
+          cast_type = lookup_cast_type(sql_type)
+          SqlTypeMetadata.new(
+            sql_type: sql_type,
+            type: cast_type.type,
+            limit: cast_type.limit,
+            precision: cast_type.precision,
+            scale: cast_type.scale,
+          )
+        end
+
         def index_column_names(column_names)
           if column_names.is_a?(String) && /\W/.match?(column_names)
             column_names
@@ -1295,6 +1287,24 @@ module ActiveRecord
           end
         end
 
+        def foreign_key_for(from_table, options_or_to_table = {})
+          return unless supports_foreign_keys?
+          foreign_keys(from_table).detect { |fk| fk.defined_for? options_or_to_table }
+        end
+
+        def foreign_key_for!(from_table, options_or_to_table = {})
+          foreign_key_for(from_table, options_or_to_table) || \
+            raise(ArgumentError, "Table '#{from_table}' has no foreign key for #{options_or_to_table}")
+        end
+
+        def extract_foreign_key_action(specifier)
+          case specifier
+          when "CASCADE"; :cascade
+          when "SET NULL"; :nullify
+          when "RESTRICT"; :restrict
+          end
+        end
+
         def validate_index_length!(table_name, new_name, internal = false)
           max_index_length = internal ? index_name_length : allowed_index_name_length
 
@@ -1315,6 +1325,19 @@ module ActiveRecord
           options.is_a?(Hash) && options.key?(:name) && options.except(:name, :algorithm).empty?
         end
 
+        def insert_versions_sql(versions)
+          sm_table = quote_table_name(ActiveRecord::SchemaMigration.table_name)
+
+          if versions.is_a?(Array)
+            sql = "INSERT INTO #{sm_table} (version) VALUES\n"
+            sql << versions.map { |v| "(#{quote(v)})" }.join(",\n")
+            sql << ";\n\n"
+            sql
+          else
+            "INSERT INTO #{sm_table} (version) VALUES (#{quote(versions)});"
+          end
+        end
+
         def data_source_sql(name = nil, type: nil)
           raise NotImplementedError
         end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 550b4cc86b..96083e6519 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -74,7 +74,7 @@ module ActiveRecord
       SIMPLE_INT = /\A\d+\z/
 
       attr_accessor :visitor, :pool
-      attr_reader :schema_cache, :owner, :logger
+      attr_reader :schema_cache, :owner, :logger, :prepared_statements
       alias :in_use? :owner
 
       def self.type_cast_config_to_integer(config)
@@ -93,8 +93,6 @@ module ActiveRecord
         end
       end
 
-      attr_reader :prepared_statements
-
       def initialize(connection, logger = nil, config = {}) # :nodoc:
         super()
 
@@ -142,26 +140,10 @@ module ActiveRecord
         end
       end
 
-      def collector
-        if prepared_statements
-          SQLString.new
-        else
-          BindCollector.new
-        end
-      end
-
-      def arel_visitor # :nodoc:
-        Arel::Visitors::ToSql.new(self)
-      end
-
       def valid_type?(type) # :nodoc:
         !native_database_types[type].nil?
       end
 
-      def schema_creation
-        SchemaCreation.new self
-      end
-
       # this method must only be called while holding connection pool's mutex
       def lease
         if in_use?
@@ -475,14 +457,6 @@ module ActiveRecord
         end
       end
 
-      def new_column(name, default, sql_type_metadata, null, table_name, default_function = nil, collation = nil) # :nodoc:
-        Column.new(name, default, sql_type_metadata, null, table_name, default_function, collation)
-      end
-
-      def lookup_cast_type(sql_type) # :nodoc:
-        type_map.lookup(sql_type)
-      end
-
       def column_name_for_operation(operation, node) # :nodoc:
         visitor.accept(node, collector).value
       end
@@ -629,6 +603,18 @@ module ActiveRecord
           columns(table_name).detect { |c| c.name == column_name } ||
             raise(ActiveRecordError, "No such column: #{table_name}.#{column_name}")
         end
+
+        def collector
+          if prepared_statements
+            SQLString.new
+          else
+            BindCollector.new
+          end
+        end
+
+        def arel_visitor
+          Arel::Visitors::ToSql.new(self)
+        end
     end
   end
 end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index 55ec112c17..f118e086bb 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -22,14 +22,6 @@ module ActiveRecord
         MySQL::Table.new(table_name, base)
       end
 
-      def schema_creation # :nodoc:
-        MySQL::SchemaCreation.new(self)
-      end
-
-      def arel_visitor # :nodoc:
-        Arel::Visitors::MySQL.new(self)
-      end
-
       ##
       # :singleton-method:
       # By default, the Mysql2Adapter will consider all columns of type <tt>tinyint(1)</tt>
@@ -171,10 +163,6 @@ module ActiveRecord
         raise NotImplementedError
       end
 
-      def new_column(*args) #:nodoc:
-        MySQL::Column.new(*args)
-      end
-
       # Must return the MySQL error number from the exception, if the exception has an
       # error number.
       def error_number(exception) # :nodoc:
@@ -346,16 +334,6 @@ module ActiveRecord
         indexes
       end
 
-      def new_column_from_field(table_name, field) # :nodoc:
-        type_metadata = fetch_type_metadata(field[:Type], field[:Extra])
-        if type_metadata.type == :datetime && field[:Default] == "CURRENT_TIMESTAMP"
-          default, default_function = nil, field[:Default]
-        else
-          default, default_function = field[:Default], nil
-        end
-        new_column(field[:Field], default, type_metadata, field[:Null] == "YES", table_name, default_function, field[:Collation], comment: field[:Comment].presence)
-      end
-
       def table_comment(table_name) # :nodoc:
         scope = quoted_scope(table_name)
 
@@ -658,10 +636,6 @@ module ActiveRecord
           end
         end
 
-        def fetch_type_metadata(sql_type, extra = "")
-          MySQL::TypeMetadata.new(super(sql_type), extra: extra)
-        end
-
         def add_index_length(quoted_columns, **options)
           if length = options[:length]
             case length
@@ -864,19 +838,12 @@ module ActiveRecord
           end
         end
 
-        def extract_foreign_key_action(specifier) # :nodoc:
-          case specifier
-          when "CASCADE"; :cascade
-          when "SET NULL"; :nullify
-          end
-        end
-
         def create_table_info(table_name) # :nodoc:
           select_one("SHOW CREATE TABLE #{quote_table_name(table_name)}")["Create Table"]
         end
 
-        def create_table_definition(*args) # :nodoc:
-          MySQL::TableDefinition.new(*args)
+        def arel_visitor
+          Arel::Visitors::MySQL.new(self)
         end
 
         def mismatched_foreign_key(message)
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb
index 10c8bd179a..9e2d0fb5e7 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb
@@ -3,6 +3,42 @@ module ActiveRecord
     module MySQL
       module SchemaStatements # :nodoc:
         private
+          def schema_creation
+            MySQL::SchemaCreation.new(self)
+          end
+
+          def create_table_definition(*args)
+            MySQL::TableDefinition.new(*args)
+          end
+
+          def new_column_from_field(table_name, field)
+            type_metadata = fetch_type_metadata(field[:Type], field[:Extra])
+            if type_metadata.type == :datetime && field[:Default] == "CURRENT_TIMESTAMP"
+              default, default_function = nil, field[:Default]
+            else
+              default, default_function = field[:Default], nil
+            end
+
+            MySQL::Column.new(
+              field[:Field],
+              default,
+              type_metadata,
+              field[:Null] == "YES",
+              table_name,
+              default_function,
+              field[:Collation],
+              comment: field[:Comment].presence
+            )
+          end
+
+          def fetch_type_metadata(sql_type, extra = "")
+            MySQL::TypeMetadata.new(super(sql_type), extra: extra)
+          end
+
+          def extract_foreign_key_action(specifier)
+            super unless specifier == "RESTRICT"
+          end
+
           def data_source_sql(name = nil, type: nil)
             scope = quoted_scope(name, type: type)
 
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb b/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb
index e399b6e499..da8d0c6992 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb
@@ -77,6 +77,9 @@ module ActiveRecord
         end
 
         private
+          def lookup_cast_type(sql_type)
+            super(select_value("SELECT #{quote(sql_type)}::regtype::oid", "SCHEMA").to_i)
+          end
 
           def _quote(value)
             case value
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index a332375b78..ea62302988 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -144,25 +144,6 @@ module ActiveRecord
           end.compact
         end
 
-        def new_column_from_field(table_name, field) # :nondoc:
-          column_name, type, default, notnull, oid, fmod, collation, comment = field
-          oid = oid.to_i
-          fmod = fmod.to_i
-          type_metadata = fetch_type_metadata(column_name, type, oid, fmod)
-          default_value = extract_value_from_default(default)
-          default_function = extract_default_function(default_value, default)
-          PostgreSQLColumn.new(
-            column_name,
-            default_value,
-            type_metadata,
-            !notnull,
-            table_name,
-            default_function,
-            collation,
-            comment: comment.presence
-          )
-        end
-
         def table_options(table_name) # :nodoc:
           if comment = table_comment(table_name)
             { comment: comment }
@@ -538,14 +519,6 @@ module ActiveRecord
           end
         end
 
-        def extract_foreign_key_action(specifier) # :nodoc:
-          case specifier
-          when "c"; :cascade
-          when "n"; :nullify
-          when "r"; :restrict
-          end
-        end
-
         # Maps logical Rails types to PostgreSQL-specific data types.
         def type_to_sql(type, limit: nil, precision: nil, scale: nil, array: nil, **) # :nodoc:
           sql = \
@@ -593,19 +566,53 @@ module ActiveRecord
           [super, *order_columns].join(", ")
         end
 
-        def fetch_type_metadata(column_name, sql_type, oid, fmod)
-          cast_type = get_oid_type(oid, fmod, column_name, sql_type)
-          simple_type = SqlTypeMetadata.new(
-            sql_type: sql_type,
-            type: cast_type.type,
-            limit: cast_type.limit,
-            precision: cast_type.precision,
-            scale: cast_type.scale,
-          )
-          PostgreSQLTypeMetadata.new(simple_type, oid: oid, fmod: fmod)
-        end
-
         private
+          def schema_creation
+            PostgreSQL::SchemaCreation.new(self)
+          end
+
+          def create_table_definition(*args)
+            PostgreSQL::TableDefinition.new(*args)
+          end
+
+          def new_column_from_field(table_name, field)
+            column_name, type, default, notnull, oid, fmod, collation, comment = field
+            type_metadata = fetch_type_metadata(column_name, type, oid.to_i, fmod.to_i)
+            default_value = extract_value_from_default(default)
+            default_function = extract_default_function(default_value, default)
+
+            PostgreSQLColumn.new(
+              column_name,
+              default_value,
+              type_metadata,
+              !notnull,
+              table_name,
+              default_function,
+              collation,
+              comment: comment.presence
+            )
+          end
+
+          def fetch_type_metadata(column_name, sql_type, oid, fmod)
+            cast_type = get_oid_type(oid, fmod, column_name, sql_type)
+            simple_type = SqlTypeMetadata.new(
+              sql_type: sql_type,
+              type: cast_type.type,
+              limit: cast_type.limit,
+              precision: cast_type.precision,
+              scale: cast_type.scale,
+            )
+            PostgreSQLTypeMetadata.new(simple_type, oid: oid, fmod: fmod)
+          end
+
+          def extract_foreign_key_action(specifier)
+            case specifier
+            when "c"; :cascade
+            when "n"; :nullify
+            when "r"; :restrict
+            end
+          end
+
           def data_source_sql(name = nil, type: nil)
             scope = quoted_scope(name, type: type)
             scope[:type] ||= "'r','v','m'" # (r)elation/table, (v)iew, (m)aterialized view
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 73cf3ac862..93c6fad039 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -121,14 +121,6 @@ module ActiveRecord
       include PostgreSQL::DatabaseStatements
       include PostgreSQL::ColumnDumper
 
-      def schema_creation # :nodoc:
-        PostgreSQL::SchemaCreation.new self
-      end
-
-      def arel_visitor # :nodoc:
-        Arel::Visitors::PostgreSQL.new(self)
-      end
-
       # Returns true, since this connection adapter supports prepared statement
       # caching.
       def supports_statement_cache?
@@ -376,11 +368,6 @@ module ActiveRecord
         PostgreSQL::Table.new(table_name, base)
       end
 
-      def lookup_cast_type(sql_type) # :nodoc:
-        oid = execute("SELECT #{quote(sql_type)}::regtype::oid", "SCHEMA").first["oid"].to_i
-        super(oid)
-      end
-
       def column_name_for_operation(operation, node) # :nodoc:
         OPERATION_ALIASES.fetch(operation) { operation.downcase }
       end
@@ -777,8 +764,8 @@ module ActiveRecord
           $1.strip if $1
         end
 
-        def create_table_definition(*args)
-          PostgreSQL::TableDefinition.new(*args)
+        def arel_visitor
+          Arel::Visitors::PostgreSQL.new(self)
         end
 
         def can_perform_case_insensitive_comparison_for?(column)
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/sqlite3/schema_statements.rb
index 4ba245a0d8..8066a05c5e 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3/schema_statements.rb
@@ -3,6 +3,31 @@ module ActiveRecord
     module SQLite3
       module SchemaStatements # :nodoc:
         private
+          def schema_creation
+            SQLite3::SchemaCreation.new(self)
+          end
+
+          def create_table_definition(*args)
+            SQLite3::TableDefinition.new(*args)
+          end
+
+          def new_column_from_field(table_name, field)
+            default = \
+              case field["dflt_value"]
+              when /^null$/i
+                nil
+              when /^'(.*)'$/m
+                $1.gsub("''", "'")
+              when /^"(.*)"$/m
+                $1.gsub('""', '"')
+              else
+                field["dflt_value"]
+              end
+
+            type_metadata = fetch_type_metadata(field["type"])
+            Column.new(field["name"], default, type_metadata, field["notnull"].to_i == 0, table_name, nil, field["collation"])
+          end
+
           def data_source_sql(name = nil, type: nil)
             scope = quoted_scope(name, type: type)
             scope[:type] ||= "'table','view'"
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index d24bfc0c93..c54b88f7d1 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -84,14 +84,6 @@ module ActiveRecord
         SQLite3::Table.new(table_name, base)
       end
 
-      def schema_creation # :nodoc:
-        SQLite3::SchemaCreation.new self
-      end
-
-      def arel_visitor # :nodoc:
-        Arel::Visitors::SQLite.new(self)
-      end
-
       def initialize(connection, logger, connection_options, config)
         super(connection, logger, config)
 
@@ -267,22 +259,6 @@ module ActiveRecord
 
       # SCHEMA STATEMENTS ========================================
 
-      def new_column_from_field(table_name, field) # :nondoc:
-        case field["dflt_value"]
-        when /^null$/i
-          field["dflt_value"] = nil
-        when /^'(.*)'$/m
-          field["dflt_value"] = $1.gsub("''", "'")
-        when /^"(.*)"$/m
-          field["dflt_value"] = $1.gsub('""', '"')
-        end
-
-        collation = field["collation"]
-        sql_type = field["type"]
-        type_metadata = fetch_type_metadata(sql_type)
-        new_column(field["name"], field["dflt_value"], type_metadata, field["notnull"].to_i == 0, table_name, nil, collation)
-      end
-
       # Returns an array of indexes for the given table.
       def indexes(table_name, name = nil) #:nodoc:
         if name
@@ -559,16 +535,8 @@ module ActiveRecord
           end
         end
 
-        def create_table_definition(*args)
-          SQLite3::TableDefinition.new(*args)
-        end
-
-        def extract_foreign_key_action(specifier)
-          case specifier
-          when "CASCADE"; :cascade
-          when "SET NULL"; :nullify
-          when "RESTRICT"; :restrict
-          end
+        def arel_visitor
+          Arel::Visitors::SQLite.new(self)
         end
 
         def configure_connection
diff --git a/activerecord/test/cases/column_definition_test.rb b/activerecord/test/cases/column_definition_test.rb
index d230700119..90c8d21c43 100644
--- a/activerecord/test/cases/column_definition_test.rb
+++ b/activerecord/test/cases/column_definition_test.rb
@@ -8,7 +8,7 @@ module ActiveRecord
         def @adapter.native_database_types
           { string: "varchar" }
         end
-        @viz = @adapter.schema_creation
+        @viz = @adapter.send(:schema_creation)
       end
 
       # Avoid column definitions in create table statements like: