Method _prepare

lib/prepare-handler.js:103–117

* Prepares the query on a single host or on all hosts depending on the options. * Uses the info 'prepared' event to emit the result. * @param {Object} info * @param {String} query * @param {String} keyspace * @returns {Promise<{queryId, meta}>}

(info, query, keyspace)

   * @returns {Promise<{queryId, meta}>}
   */
  async _prepare(info, query, keyspace) {
    info.preparing = true;
    let iterator;

    try {
      iterator = await promiseUtils.newQueryPlan(this._loadBalancing, keyspace, null);
      return await this._prepareWithQueryPlan(info, iterator, query, keyspace);
    } catch (err) {
      info.preparing = false;
      err.query = query;
      info.emit('prepared', err);

      throw err;
    }
  }

  /**
   * Uses the query plan to prepare the query on the first host and optionally on the rest of the hosts.