Hi guys,

I'm new to Hibernate and I'm trying out a one-to-many design mapping, but I'm stuck in between. Can someone please help me?

Storyline,
Table 1 consists of 3 column where visit_id is the primary key
Table 2 consist of 3 column where crane_id and visit_id is the composite primary key, visit id is the foreign key of table 1.
In some how, I need to manually assign the visit id, and crane id.
1 trx_visit can have many trx_visit_crane
I trx_visit_crane can only belongs to 1 trx_visit.

Here is the case, 2 tables
- table 1, straight forward
TrxVisit consists of visit_id, visit_type, and visit_carrier

<class name="TrxVisit" table="trx_visit">
<id name="visitId" column="visit_id" type="java.lang.String">
<generator class="assigned"/>
</id>
<property name="visitType" column="visit_type" type="java.lang.String" length="2" not-null="true"/>
<property name="visitCarrier" column="visit_carrier" type="java.lang.String" length="255" not-null="true"/>
<set name="visitId" table="trx_visit_crane">
<key>
<column name="visitId" not-null="true"/>
</key>
<one-to-many class="berth.hibernate.entity.TrxVisitCrane"/>
</set>
</class>

-table 2
<class name="TrxVisitCrane" table="trx_visit_crane">
<composite-id>
<key-property name="craneId" column="crane_id" type="java.lang.String" length="5"/>
<key-property name="visitId" column="visit_id" type="java.lang.String" length="12"/>
</composite-id>
<property name="craneMph" column="crane_mph" type="java.lang.Integer" length="3" not-null="true"/>
<many-to-one name="visitId" column="visit_id" not-null="true" class="berth.hibernate.entity.TrxVisit" insert="false" update="false"/>
</class>

Did I define the mapping correctly?

Thanks in advance.

<key-many-to-one> tag is what you want.
Section 4.1.5 of the reference guide.

Hi,

Good advice, but where I trying to do something like below, it gives me error : No persisit for: java.lang.String error executing query for TrxVisit

<class name="berth.hibernate.entity.TrxCrane" table="trx_crane">
<composite-id>
<key-property name="craneId" column="crane_id" type="java.lang.String" length="5"/>
<key-many-to-one name="cvisitId" column="cvisit_id" type="java.lang.String" length="10"/>
</composite-id>
<property name="craneMph" column="crane_mph" type="java.lang.Integer" length="3" not-null="true"/>
</class>

<class name="berth.hibernate.entity.TrxVisit" table="trx_visit">
<id name="visitId" column="visit_id" type="java.lang.String">
<generator class="assigned"/>
</id>
<property name="visitType" column="visit_type" type="java.lang.String" length="2" not-null="true"/>
<property name="visitCarrier" column="visit_carrier" type="java.lang.String" length="255" not-null="true"/>
<set name="cranes">
<key column="cvisit_id"/>
<one-to-many class="berth.hibernate.entity.TrxCrane"/>
</set>
</class>

below are my class structure
public class TrxVisit implements Serializable {
private String visitId;
private String visitType;
private String visitCarrier;
private Set cranes;

/** full constructor */
/** default constructor */
/** all the getter and setter method */

public boolean equals(Object other) {
if ( !(other instanceof TrxVisit) ) return false;
TrxVisit castOther = (TrxVisit) other;
return new EqualsBuilder()
.append(this.getVisitId(), castOther.getVisitId())
.isEquals();
}

public int hashCode() {
return new HashCodeBuilder()
.append(getVisitId())
.toHashCode();
}
}

public class TrxCrane implements Serializable {
private String craneId;
private String cvisitId;
private Integer craneMph;
/** full constructor */
/** default constructor */
/** all getter and setter method */
public boolean equals(Object other) {
if ( !(other instanceof TrxCrane) ) return false;
TrxCrane castOther = (TrxCrane) other;
return new EqualsBuilder()
.append(this.getCraneId(), castOther.getCraneId())
.append(this.getCvisitId(), castOther.getCvisitId())
.isEquals();
}

public int hashCode() {
return new HashCodeBuilder()
.append(getCraneId())
.append(getCvisitId())
.toHashCode();
}
}

Sure, you map the many-to-one on a String.



There may be some samples on the forum you can search.

Let me try :)