Re: BUG #2393: update fails with unique constraint violation

Laurence,

that error is correct:

> CREATE TABLE test.test
> (
> a int4 NOT NULL DEFAULT nextval('test.test_a_seq'::regclass),
> CONSTRAINT pk PRIMARY KEY (a)
> )
> WITHOUT OIDS;
> And then try an update:
> lstore=> select * from test.test;
> a
> ----
> 1
> 2
> 3
> 4
> 5
> 6
> 7
> 8
> 9
> 10
>
> lstore=> update test.test set a = a + 2 where a >= 3;
> ERROR: duplicate key violates unique constraint "pk"
>

it starts anywhere in the table and updates line by line. So if it starts
with, say, a=4, it trys to set a=4+2, giving 6 which is allready present.

possible solution: create a temp table from a select with that a+x, and then
freshen your data from there.

On a side node ... if you have to change your PRIMARY KEY in this fashion,
there is propably a design error within your database scheme / application.

Best wishes

Harald

--
GHUM Harald Massa
persuadere et programmare
Harald Armin Massa
Reinsburgstraße 202b
70197 Stuttgart
0173/9409607
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