Some records are missing in result

[avackova]

MyBatis version

3.3.0

Database vendor and version

DB2 for AS400

Test case or example project

Steps to reproduce

Result map:

    <resultMap type="cz.pse.agata.commons.dto.Security" id="detailed_security">
    <result property="id" column="VAID"/>
    <result property="issueId" column="VAIDVA"/>
    <result property="effectiveDate" column="VAEFDT"/>
    <result property="bic" column="VABIC"/>
    .
    .
    .
    <association property="isin" column="VACVAL" javaType="cz.pse.agata.commons.dto.ISIN">
        <result property="isin" column="VACVAL"/>
    </association>
    <association property="legalPerson" javaType="cz.pse.agata.commons.dto.LegalPerson"
            resultMap="legalPerson" columnPrefix="specialist_person_"/>
    </association>  
    <association property="emitent" column="VAEMIT" javaType="cz.pse.agata.commons.dto.LegalPerson"
        resultMap="cz.pse.agata.commons.dto.mapper.LegalPersonMapper.legalPerson"/>
    <association property="administrator" column="VAIDAD" javaType="cz.pse.agata.commons.dto.LegalPerson" 
        resultMap="legalPerson"/>
    <association property="changeReason" column="VAIDCD" javaType="cz.pse.agata.commons.dto.ChangeReason">
        <result property="id" column="CDID"/>
        <result property="reason" column="CDTEXT"/>
    </association>
    <association property="tail" javaType="Object">
         <discriminator javaType="String" column="VATVAL">
            <case value="000" resultType="cz.pse.agata.commons.dto.SecurityTailImpl">
                <result property="issueId" column="VAIDVA"/>
            </case>
            <case value="520" resultType="cz.pse.agata.commons.dto.SecurityTailImpl">
                <result property="issueId" column="VAIDVA"/>
            </case>
            <case value="100" resultMap="cz.pse.cp.dto.mapper.BondMapper.Bond"/>
            <case value="150" resultMap="cz.pse.cp.dto.mapper.BondMapper.Bond"/>
            <case value="200" resultMap="cz.pse.cp.dto.mapper.BondMapper.Bond"/>
            <case value="500" resultType="cz.pse.agata.commons.dto.SecurityTailImpl">
                <result property="issueId" column="VAIDVA"/>
            </case>
            <case value="510" resultType="cz.pse.agata.commons.dto.SecurityTailImpl">
                <result property="issueId" column="VAIDVA"/>
            </case>
            <case value="610" resultMap="cz.pse.cp.dto.mapper.WarrantMapper.Warrant"/>
            <case value="660" resultMap="cz.pse.cp.dto.mapper.WarrantMapper.Warrant">
                <result property="id" column="WAID"/>
            </case>
            <case value="600" resultMap="cz.pse.cp.dto.mapper.InvestementCertificateMapper.InvestementCertificate"/>
            <case value="650" resultMap="cz.pse.cp.dto.mapper.InvestementCertificateMapper.InvestementCertificate"/>
            <case value="300" resultType="cz.pse.agata.commons.dto.SecurityTailImpl">
                <result property="issueId" column="VAIDVA"/>
            </case>
            <case value="305" resultType="cz.pse.agata.commons.dto.SecurityTailImpl">
                <result property="issueId" column="VAIDVA"/>
            </case>
            <case value="400" resultType="cz.pse.agata.commons.dto.SecurityTailImpl">
                <result property="issueId" column="VAIDVA"/>
            </case>
        </discriminator>
    </association>
  </resultMap>

Expected result

List of four items:

==>  Preparing: with dates as ( select vaefdt as dat from ....
 ==> Parameters: 109735(Long), 109735(Long), ....
<==      Total: 4

Actual result

List of three items.

After some debugging I realized, that it happens (probably) because 2 of the 4 rows have all data the same except tail values (method org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleRowValuesForNestedResultMap(ResultSetWrapper, ResultMap, ResultHandler, RowBounds, ResultMapping)):

 private void handleRowValuesForNestedResultMap(ResultSetWrapper rsw, ResultMap resultMap, ResultHandler resultHandler, RowBounds rowBounds, ResultMapping parentMapping) throws SQLException {
    final DefaultResultContext resultContext = new DefaultResultContext();
    skipRows(rsw.getResultSet(), rowBounds);
    Object rowValue = null;
    while (shouldProcessMoreRows(resultContext, rowBounds) && rsw.getResultSet().next()) {
      final ResultMap discriminatedResultMap = resolveDiscriminatedResultMap(rsw.getResultSet(), resultMap, null);
      final CacheKey rowKey = createRowKey(discriminatedResultMap, rsw, null);
==>      Object partialObject = nestedResultObjects.get(rowKey);             <==
      // issue #577 && #542
      if (mappedStatement.isResultOrdered()) {
==>      if (partialObject == null && rowValue != null) {
          nestedResultObjects.clear();
          storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
        }     <==
        rowValue = getRowValue(rsw, discriminatedResultMap, rowKey, rowKey, null, partialObject);
      } else {
        rowValue = getRowValue(rsw, discriminatedResultMap, rowKey, rowKey, null, partialObject);
        if (partialObject == null) {
          storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
        }
      }
    }
    if (rowValue != null && mappedStatement.isResultOrdered() && shouldProcessMoreRows(resultContext, rowBounds)) {
      storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
    }
  }

Note marked (==> <==) text above: for the 2nd iteration proper rowValue is created, but it is not added to the result, because partialObject is not null.

[emacarron]

Hi! Can you plese check 3.3.1? (just in case)

[avackova]

The same behavior with 3.3.1.

[avackova]

The problem is not only for discriminator. The issue occurs for following simple mapping also:

  <resultMap type="cz.pse.cp.dto.Invoice" id="invoice">
    <result property="active" column="P0PLAT" typeHandler="cz.pse.commons.mybatis.handler.BooleanCZShort"/>
    <result property="calculatedPrice" column="P0MTMV"/>
    <association property="invoice" resultMap="cz.pse.dto.mapper.InvoiceDataMapper.invoiceData"/>
  </resultMap>

Resulting list contains only records, which are different on fields P0PLAT and P0MTMV!!!!!
(Record, that has both fields of the same value as any of the previous records is not added to resulting list).

[harawata]

I think what you are seeing is the expected behavior.
Please see the comments in these similar reports ( #512 , #522 )

[avackova]

I'm not sure if it is not a bug for discriminator. Without discriminator I can avoid using association by using dot notation. But it is impossible with discriminator. Is there a way to obtain all records in this case?

[h7io]

Hi,
bug should be fixed in #682

[harawata]

I should have mentioned that you can define 'id' elements without mapping it to the Java object.
As your result map only contains 'association' elements, it could be a row number.
Please see the test case here.

[kazuki43zoo]

Hi @avackova , How is it ?

[harawata]

I'll close. This is not a bug and there is a workaround.