code: String getQuery(String key)
      {
          String res = this.adapter.getSqlText(key);
          if (res == null)
          {
              throw new DatabaseException("Query " + key + " does not exist");
          }
          return res;
      }
docs: Gets the interpolated text of a query from cache. If key does not exist, an exception is thrown.
  
  @param key
  name of the query
  @return the query text