Description
Processing relational model in Prolog
A relational model of the data is based on table representation.
A data set can be represented as a list of items. Each item includes a certain number of
fields: each field is identified by its name, a string of characters, and the value of a field can
be typically of type: Boolean, String, Integer or Real.
Here are two examples of relations presented under form of tables:
“Name” “Course” “Course” “Prof” “Local”
“John” “COMP232” “COMP232” “Tim W.” “H6010”
“Louise” “COMP248” “COMP248” “Louise L.” “H5605”
“William” “COMP348” “COMP348” “Mohamed T.” “H7610”
“William” “COMP232”
Relation Registration Relation Assignment
The objective is to represent and manipulate these relations in Prolog.
We admit to represent a relation with a predicate name relation, and having as arguments a
list of column headers and a list of elements representing the contents of the table. The list
of elements corresponds in fact to values of the fields of the table. Each element is
represented by the predicate element with as argument a value of type integer, real or string
of characters.
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In addition, we admit that in valid relation, headers of the column do not contain repetitions
(otherwise there would be a risk of ambiguity), each row has the same length of the list of
headers of columns and the data type in a column is the same of one row to another. The
predicate verifRelation presented in the file C348SA1.pl verifies whether a relation is wellformed.
REQUESTED WORK
You need to implement in Prolog two operations on relations, namely:
1. projection(list of columns to remember, relation) that produces a new relation by
containing only the specified columns of the original relation. For example:
relation1(Assignment), projection([“Course”, “Local”], Assignment, RelationR).
produces the relation “RelationR” with following values:
“Course” “Local”
“COMP232” “H6010”
“COMP248” “H5605”
“COMP348” “H7610”
2. join(list of columns to be matched, relation1, relation2) that produces a new
relation obtained by welding rows together from the relation1 and relation2 that
have identical values of fields in specified columns by taking care to remove
columns that are repeated. For example:
relation1(Registration), relation2(Assignment), join([‘Course’], Registration,
Assignment, RelationR).
produces the relation “RelationR” with following values:
“Name” “Course” “Prof” “Local”
“John” “COMP232” “Tim W.” “H6010”
“Louise” “COMP248” “Louise L.” “H5605”
“William” “COMP348” “Mohamed T.” “H7610”
“William” “COMP232” “Tim W.” “H6010”
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/*******************************************************************************************/
/* COMPILATION – EXECUTION – RESULTS */
/*******************************************************************************************/
?- compile(‘prolog/C348SA1.pl’).
% compiling file/usagers/prolog/C348SA1.pl
% C348SA1.pl compiled in module user, 1.490 sec 4,940 bytes
yes
?- relation2(Assignment), projection([‘Course’, ‘Local’], Assignment, RelationR).
RESULT:
Assignment = relation([‘Course’, ‘Prof’, ‘Local’],
[[‘COMP232′,’Tim W.’,’H6010′],
[‘COMP248′,’Louise L.’,’H5605′],
[‘COMP348′,’Mohamed T.’,’H7610′]]),
RelationR = relation( [‘Course’, ‘Local’],
[[‘COMP232′,’H6010’],
[‘COMP248′,’H5605’],
[‘COMP348’, ‘H7610’]]).
?- relation1(Registration), relation2(Assignment), join([‘Course’], Registration,
Assignment, RelationR).
RESULT:
Registration = relation([‘Name’, ‘Course’],
[[‘John’, ‘COMP232’],
[‘Louise’,’COMP248′],
[‘William’,’COMP348′],
[‘William’,’COMP232′]]),
Assignment = relation([‘Course’, ‘Prof’, ‘Local’],
[[‘COMP232′,’Tim W.’,’X6010′],
[‘COMP248′,’Louise L.’,’H5605′],
[‘COMP348′,’Mohamed T.’,’H7610′]]),
RelationR = relation([‘Name’, ‘Course’, ‘Prof’, ‘Local’],
[[‘John’, ‘COMP232′,’Tim W.’,’H6010′],
[‘Louise’,’COMP248′,’Louise L.’,’H5605′],
[‘William’,’COMP348′,’Mohamed T.’,’H7610′],
[‘William’,’COMP232′,’Tim W.’,’H6010′]]).
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Evaluation Criteria or Assignment #1 (7.5 points)
Assignment (7.5 points)
Finding the arguments of clause Projection 2 pts.
Implementing the clause Projection 2 pts.
Finding the arguments of clause Join 1 pt.
Implementing the clause Join 1 pt.
Testing and validating the clause Projection 0.5 pt.
Testing and validating the clause Join 0.5 pt.
General correctness of code 0.5 pt.
EDUCATIONAL GUIDELINES
The file C348SA1.pl contains a description of the structure and the main data to be
manipulated in this assignment. It serves as a basis working and must be completed
with the requested clauses.
You must respect strictly the format of the requested predicates, including the
number and names of their arguments.
Your work is not to develop new rules in the program but rather to reuse rules that
are provided in the program. Therefore, no new rule will be accepted.
The work is realized in a team members 4 students.
The delivery must be made no later than Sunday, May 19th, 2019 by midnight
11:59 PM using the Website submission as mentioned in the course outlines.
