Re: UPDATE sql question

On Mon, 2003-07-28 at 03:24, Andrei Verovski wrote:
> Hi,
>
> What exactly will happen if UPDATE sql statement instructs to update
> some columns with the same values as already in the database? Will
> Postgres update only different values or it will simply modify all
> columns listed in UPDATE sql?

You mean this:

template1=# create table foo (f1 integer);
CREATE TABLE

template1=# insert into foo values (1);
INSERT 16992 1

template1=# insert into foo values (2);
INSERT 16993 1

template1=# insert into foo values (1);
INSERT 16994 1

template1=# insert into foo values (3);
INSERT 16995 1

template1=# select * from foo;
1
2
1
3

template1=# update foo set f1 = 1 where f1 = 1;
UPDATE 2

template1=# select * from foo;
2
3
1
1

Looks like it does what you tell it to do...

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