select h1.fornecedor
from historico_es_equip_prod h1
where h1.equip_prod_fk=11 and h1.data_saida = (
               select max(h2.data_saida)
               from historico_es_equip_prod h2
               where h2.equip_prod_fk=h1.equip_prod_fk and h2.data_entrada is null)

( ... )
List res = session.find("select hep1.fornecedor from vo.HistoricoEsEquipProd hep1 " +
"where hep1.equipProd = ? and hep1.dataSaida = (select max(hep2.dataSaida) from vo.HistoricoEsEquipProd hep2 where hep2.equipProd = hep1.equipProd and hep2.dataEntrada is null)"
,equip_prod_id, Hibernate.LONG);
( ... )

( ... )
List res = session.find("select hep1.fornecedor from vo.HistoricoEsEquipProd hep1 join hep1.equipProd ep1 " +
"where ep1 = ? and hep1.dataSaida = (select max(hep2.dataSaida) from vo.HistoricoEsEquipProd hep2 join hep2.equipProd ep2 where ep2 = ep1 and hep2.dataEntrada is null)"
,equip_prod_id, Hibernate.LONG);
( ... )

select historicoe0_.fornecedor as x0_0_

from historico_es_equip_prod historicoe0_

where (historicoe0_.equip_prod_fk=? )
and(historicoe0_.data_saida=(
            select max(historicoe1_.data_saida)
            from historico_es_equip_prod historicoe1_
            where (historicoe1_.equip_prod_fk=historicoe0_.equip_prod_fk )and(historicoe1_.data_entrada is null )))

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >
   
<hibernate-mapping>
<!--
    Created by Middlegen Hibernate plugin

    http://boss.bekk.no/boss/middlegen/
    http://hibernate.sourceforge.net/
-->

<class
    name="vo.HistoricoEsEquipProd"
    table="historico_es_equip_prod"
>

    <id
        name="id"
        type="long"
        column="id"
    >
        <generator class="sequence">
           <param name="sequence">historico_es_equip_prod_seq</param>
        </generator>
    </id>

    <property
        name="dataEntrada"
        type="java.sql.Timestamp"
        column="data_entrada"
        length="8"
    />
    <property
        name="dataSaida"
        type="java.sql.Timestamp"
        column="data_saida"
        not-null="true"
        length="8"
    />
    <property
        name="fornecedor"
        type="java.lang.String"
        column="fornecedor"
        not-null="true"
        length="-1"
    />

    <!-- associations -->
    <!-- bi-directional many-to-one association to EquipProd -->
    <many-to-one
        name="equipProd"
        class="vo.EquipProd"
        not-null="true"
    >
        <column name="equip_prod_fk" />
    </many-to-one>

</class>
</hibernate-mapping>

select historicoe0_.fornecedor as x0_0_

from historico_es_equip_prod historicoe0_

where (historicoe0_.equip_prod_fk=? )
and(historicoe0_.data_saida=(
            select max(historicoe1_.data_saida)
            from historico_es_equip_prod historicoe1_
            where (historicoe1_.equip_prod_fk=historicoe0_.equip_prod_fk )and(historicoe1_.data_entrada is null )))

ERROR:  operator does not exist: bigint =?
HINT:  No operator matches the given name and argument type(s). You may need to add explicit type casts.

CREATE TABLE HISTORICO_ES_EQUIP_PROD (
       id INT8 NOT NULL
     , equip_prod_fk INT8 NOT NULL
     , data_entrada TIMESTAMP
     , data_saida TIMESTAMP NOT NULL
     , fornecedor TEXT NOT NULL
     , PRIMARY KEY (id)
     , CONSTRAINT hist_es_equip_prod_fk FOREIGN KEY (equip_prod_fk)
                  REFERENCES EQUIP_PROD (id)
);