Mybatis resultmap ​only outputs one of three records - mybatis

Question

I have 3 records to be populated from a medication table​:​
select * from ccda_medication where client_id = 100009;
client_id | rxcui | drug | medicationtime | status | directions |pharmacynote
-----------+--------+---------------------------------------+----------------+--------+------------------------------------+
100009 | 573621 | Albuterol 0.09 MG/ACTUAT [Proventil] | 20120806 | ACTIVE | 2 puffs every 6 hours PRN wheezing |
100009 | 866924 | Metoprolol Tartrate 25 MG Oral Tablet | 20120806 | ACTIVE | by mouth once daily|
100009 | 197517 | Clarithromycin 500 MG Oral Tablet | 20120806 | ACTIVE | by mouth twice daily for 7 days|
(3 rows)
The debug also shows that 3 records were retrieved from database.
==> Preparing: select * from ccda_medication where client_id = ?
==> Parameters: 100009(Integer)
<==Columns: client_id, rxcui, drug, medicationtime, status, directions, pharmacynote
<==Row: 100009, 573621, Albuterol 0.09 MG/ACTUAT [Proventil], 20120806, ACTIVE, 2 puffs every 6 hours PRN wheezing,
<==Row: 100009, 866924, Metoprolol Tartrate 25 MG Oral Tablet, 20120806, ACTIVE, by mouth once daily,
<==Row: 100009, 197517, Clarithromycin 500 MG Oral Tablet, 20120806, ACTIVE, by mouth twice daily for 7 days,
<== Total: 3
but I only g​e​t one record ​when I call selectMedications- the last one: Row: 100009, 197517
​Interestingly, if I ​flatten out Substance to contain all fields directly (no inner class), I get all 3 records, so the column names are correct.
The Mapper file is as the following:
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="ccda.mapper.interfaces.MedicationMapper">
<select id="**selectMedications**"
resultMap="MedicationsResultMap"
parameterType="Integer">
select * from ccda_medication where client_id = #{id}
</select>
<resultMap id="MedicationsResultMap" type="ccda.model.Substance">
<result property="status" column="status"/>
<association property="substanceTime" javaType="ccda.model.EffectiveTime">
<result property="low" column="medicationtime"/>
<result property="high" column="medicationtime"/>
</association>
<association property="medication" javaType="ccda.model.Medication">
<result property="rxcui" column="rxcui"/>
<result property="drug" column="drug"/>
<result property="directions" column="directions"/>
<result property="fillInstructions" column="pharmacynote"/>
</association>
</mapper>
The Substance, Medication and MedicationMapper are as the following:
package ccda.model;
public class Substance
{
public String status;
public EffectiveTime substanceTime;
public Medication medication;
}
package ccda.model;
public class Medication
{
public int rxcui;
public String drug;
public String directions;
public String fillInstructions;
}
package ccda.mapper.interfaces;
import java.util.List;
import ccda.model.Medication;
import ccda.model.Substance;
public interface MedicationMapper
{
List<Substance> selectMedications( int id );
}
​Can you please help me figure out why is that? Thanks A LOT!

Answer 1

The problem is that identifier field for substance is not specified. Because of this mybatis doesn't know what is the identity of returned entities and in this case it thinks that all records refer to the same entity.
So specify id in the resultMap and use unique field from ccda_medication for it.