diff options
Diffstat (limited to 'activerecord/lib/active_record/internal_metadata.rb')
-rw-r--r-- | activerecord/lib/active_record/internal_metadata.rb | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/internal_metadata.rb b/activerecord/lib/active_record/internal_metadata.rb new file mode 100644 index 0000000000..17a5dc1d1b --- /dev/null +++ b/activerecord/lib/active_record/internal_metadata.rb @@ -0,0 +1,56 @@ +require 'active_record/scoping/default' +require 'active_record/scoping/named' + +module ActiveRecord + # This class is used to create a table that keeps track of values and keys such + # as which environment migrations were run in. + class InternalMetadata < ActiveRecord::Base # :nodoc: + class << self + def primary_key + "key" + end + + def table_name + "#{table_name_prefix}#{ActiveRecord::Base.internal_metadata_table_name}#{table_name_suffix}" + end + + def original_table_name + "#{table_name_prefix}active_record_internal_metadatas#{table_name_suffix}" + end + + def []=(key, value) + find_or_initialize_by(key: key).update_attributes!(value: value) + end + + def [](key) + where(key: key).pluck(:value).first + end + + def table_exists? + ActiveSupport::Deprecation.silence { connection.table_exists?(table_name) } + end + + def original_table_exists? + # This method will be removed in Rails 5.1 + # Since it is only necessary when `active_record_internal_metadatas` could exist + ActiveSupport::Deprecation.silence { connection.table_exists?(original_table_name) } + end + + # Creates an internal metadata table with columns +key+ and +value+ + def create_table + if original_table_exists? + connection.rename_table(original_table_name, table_name) + end + unless table_exists? + key_options = connection.internal_string_options_for_primary_key + + connection.create_table(table_name, id: false) do |t| + t.string :key, key_options + t.string :value + t.timestamps + end + end + end + end + end +end |