Module: UuidV7::Patches::Mysql::FkHelper

Defined in:
lib/uuid_v7/patches/mysql/fk_helper.rb

Instance Method Summary collapse

Instance Method Details

#update_fk_uuid_between_table(parent_table_name:, child_table_name:) ⇒ Object

update_fk_uuid_between_table(parent_table_name: :engines, child_table_name: :pistons)



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# File 'lib/uuid_v7/patches/mysql/fk_helper.rb', line 8

def update_fk_uuid_between_table(parent_table_name:, child_table_name:)
  table_name_parent = parent_table_name.to_s.to_sym # :engines
  table_name_child  = child_table_name.to_s.to_sym  # :pistons
  foreign_key_id    = :"#{table_name_parent.to_s.singularize}_id"   # :engine_id
  foreign_key_uuid  = :"#{table_name_parent.to_s.singularize}_uuid" # :engine_uuid

  add_column table_name_child, foreign_key_uuid, :binary, limit: 16, null: true # :pistons, :engine_uuid

  # Update the foreign_key in child table
  connection.execute <<-SQL.squish
    UPDATE #{table_name_child} child
    JOIN #{table_name_parent} parent ON child.#{foreign_key_id} = parent.id
    SET child.#{foreign_key_uuid} = parent.uuid;
  SQL

  # change_column_null :pistons, :engine_uuid, false
  change_column_null table_name_child, foreign_key_uuid, false

  # add_index :pistons, :engine_uuid
  add_index table_name_child, foreign_key_uuid

  # add_foreign_key :pistons, :engines, column: :engine_uuid, primary_key: :uuid, type: :binary
  add_foreign_key table_name_child, table_name_parent, column: foreign_key_uuid, primary_key: :uuid, type: :binary

  # remove_column table_name_child, foreign_key_id
  # rename_column table_name_child, foreign_key_uuid, foreign_key_id
end