Information Technology Reference
In-Depth Information
while publications and conference proceedings are represented by a general PDF
icon or thumbnail of the front page. Based on this relational schema, Listing 1
now defines the necessary browser and viewer classes using an enhanced version
of SQL, which we will describe in more detail later.
CREATE VIEWER
VR AUTH
(
"Name"
(
SELECT
CONCAT
(
a
.
first name
,
""
,
a
.
last name
)
AS
tag
,
COUNT
(
ap
.
publication id
)
AS
count
,
a
.
id
,
ap
.
author id
FROM
Authors
AS
a
,
Authored
AS
ap
WHERE
a
.
id
=
ap
.
author id
GROUPBY
ap
.
publication id
RANGE
15)
LINE MULTISELECT
,
);
CREATE VIEWER
VR PUB
(
"Titles"
(
SELECT
title
AS
tag
FROM
Publications
LIMIT
30)
LIST
,
"Keywords"
(
SELECT
SPLIT
(
keywords
)
AS
tag
FROM
Publications
LIMIT
100
ORDERBY
tag
ASC
)
LINE
,
);
CREATE VIEWER
VR CONF
(
"Name"
(
SELECT
c
.
name
AS
tag
,
COUNT
(
p
.
id
)
AS
count
,
c
.
id
,
p
.
conference id
FROM
Conferences
AS
c
,
Publications
AS
p
WHERE
c
.
id
=
p
.
conference id
GROUPBY
p
.
id
ORDERBY
c
.
name
ASC
)
LINE
,
"Year"
(
SELECT
c
.
year
AS
tag
,
COUNT
(
c
.
year
)
AS
count
,
c
.
id
,
p
.
conference id
FROM
Conferences
AS
c
,
Publications
AS
p
WHERE
c
.
id
=
p
.
conference id
GROUPBY
c
.
year
ORDERBY
c
.
year
DESC
)
SPIRAL
,
);
CREATE BROWSER
BPUBLICATIONS
(
"Publications"
VR PUB
,
"Authors"
VR AUTH
,
"Conferences"
VR CONF
,
);
Listing 1.
Example browser in SQL
The first viewer class,
VR AUTH
, defines a single view over all authors with
each
tag
built using SQL's standard
CONCAT
function to combine the first and
last names. The tag size is calculated using an SQL count over the authored
publications. This view is then associated with a horizontal, line-based tag cloud
visualisation that will use
count
to make the size of an author's name dependent
on the number of publications that they have. The viewer also allows for multiple
selections of authors so that publications authored or co-authored by selected
authors will be shown. Additionally, we use ranges in the case that more than
15 authors are displayed in the cloud. The next viewer,
VR PUB
, associates
a view over all titles of the publications with a vertical list visualisation. An
alternative view of the publications is defined as the top 100 keywords in a
line-based tag cloud. Here we use a non-standard SQL function
SPLIT
that we
have defined to parse a comma-separated
VARCHAR
value and return the set
of tokens.
VR CONF
defines a primary view for conferences by name, where the
