code: func (kv *keyValue) SchemaVersion() (version int, err error) {
  	err = kv.db.QueryRow("SELECT value FROM " + kv.KeyValue.TablePrefix + "meta WHERE metakey='version'").Scan(&version)
  	if err == sql.ErrNoRows {
  		return 0, nil
  	}
  	return
  }
docs: // SchemaVersion returns the schema version found in the meta table. If no
  // version is found it returns (0, nil), as the table should be considered empty.