Package org.apache.storm.jdbc.mapper

# Interface JdbcLookupMapper

All Superinterfaces:
  `JdbcMapper`, `Serializable`

All Known Implementing Classes:
  `SimpleJdbcLookupMapper`

public interface JdbcLookupMapper extends JdbcMapper

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `declareOutputFields(OutputFieldsDeclarer declarer)`
  declare what are the fields that this code will output.
  `List<Values>`
  `toTuple(ITuple input, List<Column> columns)`
  Converts a DB row to a list of storm values that can be emitted.

  ### Methods inherited from interface org.apache.storm.jdbc.mapper.JdbcMapper

  `getColumns`

- ## Method Details

  - ### toTuple

    List<Values> toTuple(ITuple input, List<Column> columns)
    Converts a DB row to a list of storm values that can be emitted. This is done to allow a single storm input tuple and a single DB row to result in multiple output values.
    Parameters:
      `input` - the input tuple.
      `columns` - list of columns that represents a row
    Returns:
      a List of storm values that can be emitted. Each item in list is emitted as an output tuple.

  - ### declareOutputFields

    void declareOutputFields(OutputFieldsDeclarer declarer)
    declare what are the fields that this code will output.