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4
O2 SQL
CREATE SCHEMA french_document
CREATE TABLE Article(
titre LONGVARCHAR
annee INTEGER
PRIMARY KEY ( title ) )
CREATE TABLE Auteur(
title LONGVARCHAR nom LONGVARCHAR
adresse_eletronique LONGVARCHAR
PRIMARY KEY ( title ) )
CREATE TABLE Auteurs(
article LONGVARCHAR auteur LONGVARCHAR
FOREIGN KEY (article) REFERENCES Article
FOREIGN KEY (auteur) REFERENCES Auteur )
Fi gu r e 4 .4 : Rel a t i on a l sch em a
french_document
4.2 Query Translation
4.2.1 Schema Update Commands
In t h is sect ion , we con sider t h e t r an slat ion of sch em a u pdat e SQL
com m an ds in t o O 2 sch em a u pdat e com m an ds.
Sch em a u pdat e SQL com m an ds ar e com m an ds for t able, view an d in dex
cr eat ion , delet ion an d m odificat ion . Th e t r an slat ion of su ch com m an ds
cor r espon ds to an u pdat e of t h e u n der lyin g O2 sch em a.
Table creation command
Cu r r en t ly, a sim ple tr an slat ion m ech an ism is u sed for gen er at in g, for
each n ewly cr eat ed t able, a cor r espon din g class in t h e O2 sch em a wit h
t h e sam e at t r ibu tes an d u sin g a defau lt t ype m appin g. Sim ple r efer en ce
at t r ibu t es, i.e. on e-t o-on e r elat ion sh ips, ar e gen er at ed in t h e th e O2
class by t ak in g pr im ar y an d for eign k ey defin it ion s in t o accou n t , as th e
in for m at ion pr ovided in t h e t able cr eat ion com m an d is n ot en ou gh for
allowin g t h e syst em t o in fer on e-t o-m an y or m an y-to-m an y
r elat ion sh ips.
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O2 OD BC User Man u al