Hi,

I am new at this forum, and I have a question regarding HQL Lejt join.

I try to left join 2 tables, patient and provider, and keep getting "Path expected for join! " erroron the second table. Appreciate it if anybody can help on this issue!

Herer is the mapping of the 2 tables/classes:

patient.hbm.xmL:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.ccg.db.test">
<class name="patient" table="patient">
<id name="patientId" column="patientId" type="int">
<generator class="native"/>
</id>
<property name="patientName" type="string" >
<column name="patientName" />
</property>
<property name="providerId" type="string" >
<column name="provId" />
</property>
<many-to-one name="provider" column="providerId" class="provider" />
</class>
</hibernate-mapping>

-------------------

provider.hbm.xml:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.ccg.db.test">
<class name="provider" table="provider">
<id name="providerId" column="providerId">
<generator class="native" />
</id>
<property name="providerName" column="providerName" />
</class>
</hibernate-mapping>

-----------------

pojo:

patient.java

package com.ccg.db.test;

import java.io.Serializable;
import java.util.List;
import org.hibernate.Session;


public class patient
implements Serializable
{
private int patientId;
private String patientName;
private String providerId; // foreign key to provider

private static final long serialVersionUID = 81073;

public static void load(Session session, List<String> values){
patient PatientInfo = new patient();

PatientInfo.setPatientId(Integer.parseInt(values.get(0)));
PatientInfo.setPatientName( values.get(1));
PatientInfo.setProviderId( values.get(2) );

session.save( PatientInfo );
}


/**
* @return the PatientId
*/
public int getPatientId() {
return patientId;
}


/**
* @param PatientId the PatientId to set
*/
public void setPatientId(int PatientId) {
this.patientId = PatientId;
}


/**
* @return the PatientName
*/
public String getPatientName() {
return this.patientName;
}

/**
* @param PatientName the PatientName to set
*/
public void setPatientName(String PatientName) {
this.patientName = PatientName;
}



/**
* @return the ProvId
*/
public String getProviderId() {
return this.providerId;
}

/**
* @param id the ProviderId to set
*/
public void setProviderId( String id ) {
this.providerId = id;
}

/**
* @return the ProvId
*/
public String getProvider() {
return this.providerId;
}

/**
* @param id the ProviderId to set
*/
public void setProvider( String id ) {
this.providerId = id;
}


/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub

}

}

provider.java:

package com.ccg.db.test;

import java.io.Serializable;
import java.util.List;

import org.hibernate.Session;

public class provider
implements Serializable
{
private String providerId;
private String providerName;

//private int patientId;
//private int providerSpec;

private static final long serialVersionUID = 81073;

public static void load(Session session, List<String> values){
provider ProviderInfo = new provider();

ProviderInfo.setProviderId( values.get(0) );
ProviderInfo.setProviderName( values.get(1));
//ProviderInfo.setProviderSpec( Integer.parseInt(values.get(2)) );

session.save( ProviderInfo );
}


/**
* @return the ProviderName
*/
public String getProviderName() {
return providerName;
}

/**
* @param ProviderName the ProviderName to set
*/
public void setProviderName(String name) {
this.providerName = name;
}



/**
* @return the ProvId
*/
public String getProviderId() {
return this.providerId;
}

/**
* @param id the ProvId to set
*/
public void setProviderId( String id ) {
this.providerId = id;
}

/*
public int getPatientId() {
return this.patientId;
}

public void setPatientId( int id ) {
this.patientId = id;
}
*/

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub

}

}

-----------------------

Here is the left join query:

select
pat.patientId, pat.patientName
from
patient as pat
left join
provider as pro
where
pat.providerId = pro.providerId



------------------

and here is the result:


0:50:08,479 INFO query:156 - Query = outerJoin
10:50:08,479 INFO query:157 - select
pat.patientId, pat.patientName
from
patient as pat
left join
provider as pro
where
pat.providerId = pro.providerId

10:50:08,698 ERROR PARSER:33 - Path expected for join!
10:50:08,698 ERROR PARSER:33 - Invalid path: 'pro.providerId'
10:50:08,698 ERROR PARSER:33 - right-hand operand of a binary operator was null
10:50:08,698 ERROR query:184 - Problem generating query.
org.hibernate.hql.ast.QuerySyntaxException: Path expected for join! [select
pat.patientId, pat.patientName
from
com.ccg.db.test.patient as pat
left join
provider as pro
where
pat.providerId = pro.providerId
]
at org.hibernate.hql.ast.QuerySyntaxException.convert(QuerySyntaxException.java:31)
at org.hibernate.hql.ast.QuerySyntaxException.convert(QuerySyntaxException.java:24)
at org.hibernate.hql.ast.ErrorCounter.throwQueryException(ErrorCounter.java:59)
at org.hibernate.hql.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:235)
at org.hibernate.hql.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:160)
at org.hibernate.hql.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:111)
at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:77)
at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:56)
at org.hibernate.engine.query.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:72)
at org.hibernate.impl.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:133)
at org.hibernate.impl.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:112)
at org.hibernate.impl.SessionImpl.createQuery(SessionImpl.java:1623)
at com.ccg.db.query.QueryManager.query(QueryManager.java:163)
at com.ccg.db.query.QueryManager.query(QueryManager.java:139)
at com.ccg.db.query.QueryManager.main(QueryManager.java:80)

End

Hello! ANyone who can anwser?!

hi
i don't have any idea for this topic

If you just need to return a list of all Patients with their Provider fields initialised, try the following:



What "fetch" does, is that is creates a join with the provider table so that the right Provider is retrieved for each
Patient.

By the way, i don't see why you've got both the column "provId" and "providerId" in your "patient" table. Isn't that
just duplicate data?