package io.ebean;

import java.sql.ResultSet;
import java.sql.SQLException;

Used with SqlQuery to map raw JDBC ResultSet to objects.

This provides a low level mapping option with direct use of JDBC ResultSet
with the option of having logic in the mapping. For example, only map some
columns depending on the values read from other columns.


For straight mapping into beans then DtoQuery would be the first choice as
it can automatically map the ResultSet into beans.


   //
   // A mapper from ResultSet into our CustomerDto bean
   //
   class CustomerMapper implements RowMapper<CustomerDto> {
    @Override
    public CustomerDto map(ResultSet rset, int rowNum) throws SQLException {
      long id = rset.getLong(1);
      String name = rset.getString(2);
      String status = rset.getString(3);
      return new CustomerDto(id, name, status);
    }
  }
  //
  // Then use the mapper
  //
  String sql = "select id, name, status from o_customer where name = ?";
 CustomerDto rob = DB.sqlQuery(sql)
   .setParameter(1, "Rob")
   .findOne(CUSTOMER_MAPPER);

Type parameters:
<T> – The type the row data is mapped into./**
 * Used with SqlQuery to map raw JDBC ResultSet to objects.
 * <p>
 * This provides a low level mapping option with direct use of JDBC ResultSet
 * with the option of having logic in the mapping. For example, only map some
 * columns depending on the values read from other columns.
 * </p>
 * <p>
 * For straight mapping into beans then DtoQuery would be the first choice as
 * it can automatically map the ResultSet into beans.
 * </p>
 *
 * <pre>{@code
 *
 *    //
 *    // A mapper from ResultSet into our CustomerDto bean
 *    //
 *    class CustomerMapper implements RowMapper<CustomerDto> {
 *
 *     @Override
 *     public CustomerDto map(ResultSet rset, int rowNum) throws SQLException {
 *
 *       long id = rset.getLong(1);
 *       String name = rset.getString(2);
 *       String status = rset.getString(3);
 *
 *       return new CustomerDto(id, name, status);
 *     }
 *   }
 *
 *
 *   //
 *   // Then use the mapper
 *   //
 *
 *   String sql = "select id, name, status from o_customer where name = ?";
 *
 *  CustomerDto rob = DB.sqlQuery(sql)
 *    .setParameter(1, "Rob")
 *    .findOne(CUSTOMER_MAPPER);
 *
 *
 * }</pre>
 *
 * @param <T> The type the row data is mapped into.
 */
@FunctionalInterface
public interface RowMapper<T> {

  
Read the data from the ResultSet and map to the return type.
Params:
resultSet – The JDBC ResultSet positioned to the current row
rowNum –    The number of the current row being mapped./**
   * Read the data from the ResultSet and map to the return type.
   *
   * @param resultSet The JDBC ResultSet positioned to the current row
   * @param rowNum    The number of the current row being mapped.
   */
  T map(ResultSet resultSet, int rowNum) throws SQLException;
}