Re: Update multiple rows in a table with different values

On 07/01/2016 07:26 AM, shankha wrote:
> Greetings,
> I have the following schema:
>
> CREATE TABLE "s"."t1"
> (
> "c1" BigSerial PRIMARY KEY,
> "c2" BigInt NOT NULL,
> "c3" BigInt
> )
> WITH (OIDS=FALSE);

Unless you have a very old version of Postgres, OIDS=FALSE is the default.

>
> INSERT INTO s.t1 (c2, c3) VALUES (10, 100);
> INSERT INTO s.t1 (c2, c3) VALUES (20, 200);
> INSERT INTO s.t1 (c2, c3) VALUES (30, 300);
> INSERT INTO s.t1 (c2, c3) VALUES (40, 400);
>
> PREPARE updateplan (BigInt, BigInt) AS
> update s.t1
> SET c3 = $2
> WHERE c2 = $1;
>
> EXECUTE updateplan (20, 250);
> ***
> PREPARE updatearrayplan(BigInt[], BigInt[]) AS
> for i in size($1)
> DO
> update s.t1
> SET c3 = $2[$i]
> WHERE c2 = $1[$i]
> END FOR

I am not familiar with the above syntax, are you using a Postgres
version different from the community version?

>
> EXECUTE updatearrayplan({20, 30}, {275, 375})
> ***
> /* 20, 200 -> 20, 275 */
> /* 30, 300 -> 30, 375 */
> ***
>
> After execution of updatearrayplan I am expecting the rows to have
> these values 20 -> 275 , 30 -> 375
>
> Is there a way to update multiple rows with different column values
> passed in as array. Also is there a guarantee that the order of the
> arrays will be maintained.
>
> Thanks
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com