3. Bases de Données I

Bases de Données I

Examen

Deux examens écrits seront organisés: le premier concerne les TP SQL assurés par M. Buys, le deuxième A CAHIER FERME concerne la théorie. La pondération est (cours : 16, TP SQL : 4).

Les étudiants du bloc complémentaire sont dispensé des TP SQL.

Références du cours

Examens antérieurs

 

Interpreter for the SPJRUD Algebra

Excellent tool developed by alumnus Sergio Mazzoleni. Here is a screenshot. The tool is online available as a web application. Alternatively, the tool can be downloaded and installed locally.

Web Application

Local Installation

  • Download the tool.
  • Download the example files.
  • Installation steps under Windows:
    • Since the tool is a web application, install WampServer (say in C:\wamp).
    • Unzip the tool and copy it in C:\wamp\www
    • In a recent version of Google Chrome or Firefox, open http://localhost/spjrud_20160912/spjrud/index.html The tool may not work correctly in other browsers (and does not work in Internet Explorer).
    • Click « start SQF editor. »
    • Load one of the example files, e.g., exo_wijsen_02.sqf

Example

The following example illustrates the syntax.

@let Likes = @relation[Drinker,Beer] {<Sergio, Orval> <Sergio, Chimay> <Sergio, La Trappe> <Jef, Orval> <Jef, Chimay> <Jef, Duvel> <Jan, Duvel> <Jan, Orval>}

@let Trappists = @relation[Trappist, Country] {<Orval, Belgium> <Chimay, Belgium> <La Trappe, Netherlands>}

% Who likes all belgian trappists in the Trappists table ?

@let Crossproduct = (@project {Drinker} Likes) @join (@rename {Trappist:Beer} (@project{Trappist} (@select {Country= »Belgium »} Trappists)))

@let NotLikesAll = @project {Drinker} (Crossproduct @minus Likes)

@let LikesAll = @project {Drinker} Likes @minus NotLikesAll

@print LikesAll