code: protected void onWhereClause(EntityMetadata metadata, Object key, CQLTranslator translator,
          StringBuilder queryBuilder, MetamodelImpl metaModel, SingularAttribute attribute) {
          // SingularAttribute idAttribute = metadata.getIdAttribute();
          if (metaModel.isEmbeddable(attribute.getBindableJavaType())) {
              Field[] fields = attribute.getBindableJavaType().getDeclaredFields();
              EmbeddableType compoundKey = metaModel.embeddable(attribute.getBindableJavaType());
  
              for (Field field : fields) {
                  if (field != null && !Modifier.isStatic(field.getModifiers())
                      && !Modifier.isTransient(field.getModifiers()) && !field.isAnnotationPresent(Transient.class)) {
                      attribute = (SingularAttribute) compoundKey.getAttribute(field.getName());
                      Object valueObject = PropertyAccessorHelper.getObject(key, field);
                      if (metaModel.isEmbeddable(((AbstractAttribute) attribute).getBindableJavaType())) {
                          onWhereClause(metadata, valueObject, translator, queryBuilder, metaModel, attribute);
                      } else {
                          String columnName = ((AbstractAttribute) attribute).getJPAColumnName();
                          translator.buildWhereClause(queryBuilder, field.getType(), columnName, valueObject,
                              CQLTranslator.EQ_CLAUSE, false);
                      }
                  }
              }
          } else {
              translator.buildWhereClause(
                  queryBuilder, ((AbstractAttribute) attribute).getBindableJavaType(), CassandraUtilities
                      .getIdColumnName(kunderaMetadata, metadata, getExternalProperties(), isCql3Enabled(metadata)),
                  key, translator.EQ_CLAUSE, false);
          }
      }
docs: On where clause.
  
  @param metadata
  the metadata
  @param key
  the compound key object
  @param translator
  the translator
  @param queryBuilder
  the query builder
  @param metaModel
  the meta model
  @param attribute
  the attribute