Re: N Plus 1 Mapping Always getting a null pointer

Jeff Butler Tue, 18 Apr 2006 14:01:15 -0700

I think you should have this:

groupBy is used to specify the fields in the current object that are used to identify unique objects. I think you want two unique BasicStakeholder objects with different lists contained. Your configuration is failing because requiremnentId is not a property of BasicStakehoder.

Jeff Butler

On 4/18/06, Eric Bauld <[EMAIL PROTECTED]> wrote:

I have been trying to get this to work for 2 days, every time iBATIS
loads the setVotes(List votes) method in BasicStakeholder the list that
is pass in is ALWAYS null no matter what changes I make.

It may be worth noting I get the same result if I put <result
property="votes" resultMap="Stakeholder.votes"/>
to <result property="votes" resultMap="I can put anything here"/> And
get the same result.

I have the following data from this query, there are votes so they
should be getting returned ????
I debuged with a breakpoint on the setVotes() method and the
BasicStakeholder object was loaded with the user id and the weight, but
the list passed in was null, for the user with id of "3" and he has 4 votes.

       SELECT v.user_id AS databaseId,
           uw.weight AS weight,
           v.user_id AS userId,
           i.instance_id AS instanceId,
           v.requirement_id AS requirementId,
           v.criteria_id AS criteriaId,
           v.value AS voteValue
       FROM vote v, user_weight uw, instance i
       WHERE i.instance_id = 1
       AND i.instance_id = uw.instance_id
       AND i.instance_id = v.instance_id
       AND uw.user_id = v.user_id

Returns
+------------+--------+--------+------------+---------------+------------+-----------+
| databaseId | weight | userId | instanceId | requirementId | criteriaId
| voteValue |
+------------+--------+--------+------------+---------------+------------+-----------+
|          3 |      5 |      3 |          1 |             1 |          1
|         9 |
|          3 |      5 |      3 |          1 |             2 |          1
|         3 |
|          3 |      5 |      3 |          1 |             3 |          1
|         1 |
|          3 |      5 |      3 |          1 |             4 |          1
|         4 |
|          4 |      9 |      4 |          1 |             1 |          1
|         9 |
|          4 |      9 |      4 |          1 |             2 |          1
|         3 |
+------------+--------+--------+------------+---------------+------------+-----------+

--------------------SQL MAP---------------------------------
<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE sqlMap
PUBLIC "-//iBATIS.com//DTD SQL Map 2.0//EN"
"http://www.ibatis.com/dtd/sql-map-2.dtd">

<sqlMap namespace="Stakeholder">

   <resultMap id="stakeMap" class=" rp.object.baseImpl.BasicStakeholder"
groupBy="requirementId">
       <result property="databaseId" column="databaseId"/>
       <result property="weight" column="weight"/>
       <result property="votes" resultMap="Stakeholder.votes"/>
   </resultMap>

   <resultMap id="votes" class="rp.object.baseImpl.BasicVote">
       <result property="userId" column="userId"/>
       <result property="instanceId" column="instanceId"/>
       <result property="requirementId" column="requirementId"/>
       <result property="criteriaId" column="criteriaId"/>
       <result property="voteValue" column="voteValue"/>
   </resultMap>

   <select id="getStakeholders" resultMap="stakeMap">
       SELECT v.user_id AS databaseId,
           uw.weight AS weight,
           v.user_id AS userId,
           i.instance_id AS instanceId,
           v.requirement_id AS requirementId,
           v.criteria_id AS criteriaId,
           v.value AS voteValue
       FROM vote v, user_weight uw, instance i
       WHERE i.instance_id = #value#
       AND i.instance_id = uw.instance_id
       AND i.instance_id = v.instance_id
       AND uw.user_id = v.user_id
   </select>

</sqlMap>

Re: N Plus 1 Mapping Always getting a null pointer

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