code: func (m *Meta) CreateDatabase(dbInfo *model.DBInfo) error {
  	dbKey := m.dbKey(dbInfo.ID)
  
  	if err := m.checkDBNotExists(dbKey); err != nil {
  		return errors.Trace(err)
  	}
  
  	data, err := json.Marshal(dbInfo)
  	if err != nil {
  		return errors.Trace(err)
  	}
  
  	return m.txn.HSet(mDBs, dbKey, data)
  }
docs: // CreateDatabase creates a database with db info.