CREATE TABLE gallet
(
  nom_gallet character varying(20) NOT NULL,
  img_gallet bytea,
  CONSTRAINT pk_gallet PRIMARY KEY (nom_gallet)
)

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
   "-//Hibernate/Hibernate Mapping DTD//EN"
   "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<hibernate-mapping package="hibernateClass">
   <class
      name="Gallet"
      table="gallet"
   >
      <meta attribute="sync-DAO">false</meta>
      <id
         name="nom_gallet"
         type="string"
         column="nom_gallet"
      >
     </id>
      <property
         name="ImgGallet"
         column="img_gallet"
         type="java.sql.Blob"
         not-null="false"
      />
         <set name="InfoModeleAvions" inverse="true">
         <key column="nom_gallet"/>
         <one-to-many class="InfoModeleAvion"/>
      </set>
   </class>   
</hibernate-mapping>

Session s=HibernateUtil.currentSession();
      Transaction tx = s.beginTransaction();
      Gallet g=new Gallet();
      File fd = new File("c:\\img.jpg");
      FileInputStream fis;
      try {
         fis = new FileInputStream(fd);
         byte[] b = new byte[512];
      fis.read(b);
           g.setNom_gallet("petit gallet de test");
      g.setImgGallet(Hibernate.createBlob(b));
      s.save(g);
      tx.commit();
      HibernateUtil.closeSession();

   
org.postgresql.util.PSQLException: ERROR: column "img_gallet" is a bytea but the expression is a bigint
.....
Caused by: java.sql.BatchUpdateException: The batch of 0 insert into Gallet (img_gallet, nom_gallet) values (17,027 small Gallet test) was canceled. GetNextException call to find out the cause.