Hibernate (n+1) select with non-PK join

Question

(n+1) select problem which I am not able to resolve. I am joining tables with non-PK column.

My schema

Records
Record_Id (PK)
Carrier_Number


Audit_Details
AuditId(PK)
Carrier_Number

There is a one-to-many relationship between Records and Audit_Details.

My records.hbm.xml

<set lazy="true" name="auditDetails" sort="unsorted"
        table="AUDIT_DETAILS" inverse="true">
        <key column="Carrier_Number" not-null="true" property-ref="carrierRefNumber"/>
        <one-to-many 
            class="com.package.AuditDtls" />
    </set>

My auditDetails.hbm.xml

<many-to-one
        class="com.package.Records" fetch="join"
        name="Records" column="Carrier_Number" not-null="true" property-ref="carrierNumber" lazy="false"/>

This produces a query like

select
    this_.CARRIER_NUMBER as CARRIER1_2_2_,
    abc1_.CARRIER_NUMBER as CARRIER8_3_0_,
    otm4_.CARRIER_NUMBER as CARRIER1_2_1_,
from
    RECORDS this_ 
inner join
    AUDIT_DETAILS abc1_ 
        on this_.CARRIER_NUMBER=abc_.CARRIER_NUMBER 
left outer join
    RECORDS otm4_ 
        on abc1_.CARRIER_NUMBER=otmp4_.CARRIER_NUMBER 
where
    this_.LOAD_ID=? 

select
    auditde0_.CARRIER_NUMBER as CARRIER8_1_        
from
    AUDIT_DTLS auditde0_ 
where
    auditde0_.CARRIER_NUMBER=?

I have tried changing to fetch="select" , changing lazy="false" and lazy="no-proxy" but nothing has worked so far. I am not sure if this problem is because of joining two tables with nonPK column. Would appreciate any suggestions.

Answer 1

The problem was with my Criteria and not mapping. Solved this problem by setting below for my criteria.

createAlias("auditDetails", "ad", CriteriaSpecification.LEFT_JOIN);

Also, updated Hibernate to 3.3 and moved to annotations and setting below solved additional selects problem.

@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name = "CARRIER_NUMBER")
public Records getRecord() {
    return record;
}