From: "Michel Cadot" Newsgroups: comp.databases.oracle.misc Subject: Re: A tricky update... Date: Wed, 6 Jun 2001 17:02:56 +0200 Organization: Guest of France Telecom Oleane's newsreading service Lines: 101 Message-ID: <9flgn1$7dv$1@s1.read.news.oleane.net> References: <5c5c8561.0106060646.15f1035@posting.google.com> Reply-To: "Michel Cadot" NNTP-Posting-Host: 195.101.229.231 X-Trace: s1.read.news.oleane.net 991839777 7615 195.101.229.231 (6 Jun 2001 15:02:57 GMT) X-Complaints-To: abuse@oleane.net NNTP-Posting-Date: Wed, 6 Jun 2001 15:02:57 +0000 (UTC) X-Newsreader: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 You can add a column to your table then create a sequence and a trigger to populate it and finaly make it a primary key. Example: v815> create table t (col number); v815> insert into t values (0); v815> / v815> commit; v815> select * from t; COL ---------- 0 0 2 ligne(s) sélectionnée(s). v815> alter table t add (id number); Table modifiée. v815> create sequence t_s; Séquence créée. v815> create or replace trigger t_t 2 before insert or update on t 3 for each row 4 begin 5 if inserting then 6 select t_s.nextval into :new.id from dual; 7 else 8 if :old.id is null then 9 select t_s.nextval into :new.id from dual; 10 end if; 11 end if; 12 end; 13 / Déclencheur créé. v815> select * from t; COL ID ---------- ---------- 0 0 2 ligne(s) sélectionnée(s). v815> update t set col=col; 2 ligne(s) mise(s) à jour. v815> select * from t; COL ID ---------- ---------- 0 1 0 2 2 ligne(s) sélectionnée(s). v815> insert into t (col) values (1); 1 ligne créée. v815> select * from t; COL ID ---------- ---------- 0 1 0 2 1 3 3 ligne(s) sélectionnée(s). v815> alter table t add constraint pk_t primary key (id); Table modifiée. -- Hope this helps Michel "Benetnasch" a écrit dans le message news: 5c5c8561.0106060646.15f1035@posting.google.com... > I have 2 rows in a table with exactly the information > in them (badly designed, I know, but it's a legacy > system). I need to update these rows so that a blank > column is assigned a unique identifier. How can I > run an SQL update on them to achieve this, please? > > Thanks for any information, > > Mark