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Presentation Manager
The Presentation Manager displays the first answer page just when the Builder and Distribu-
tor Module sends the query to the appropriate wrappers.This Web page presents the list of dig-
ital libraries where the query is going to be executed. For each digital library, the following
attributes (using unqualified Dublin Core fields)
are specified: the name or title of the database;
a description of the data stored in the database; a surface address, a telephone number or e-mail
contact; the date of the last update; the main URL of the digital library; and the query that is to
be executed in the database (it is possible that the database does not include some of the concepts
Dublin Core Metadata Initiative,
<attribute name="Title">
<required>and ob.titulo like '#value#'</required>
<optional end=""> and ob.titulo like '#value#'
Illustration 3: Fragment of Mapping Tree for the
Emblem Book Database.
(a) XML
(b) SQL
<concept= ,,Work">
<contains limit=»1»>
<value cons=»verdad»>
<contains limit=»1»>
<value cons=»juan»>
select cod_obra, cod_emblem
from obra ob, emblema em
where ob.cod_obra = em.cod_obra
and ob.titulo like "%verdad%"
and ob.autor like "%juan%"
Illustration 4:Table of XML query and the generated
SQL for the Emblem Literature database..
select tituloabre, cod_edic
from relacion rel, edicion ed
where rel.tituloabre = ed.tituloabre
and contains(rel.titulo, `verdad', 10) > 0
and contains(rel.autor, `juan', 20) > 0
Illustration 5: Query to Early Spanish Press database.
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