Re: Update multiple rows in a table with different values

Hi Adrian,
I am using Postgres version 9.3.

PREPARE updatearrayplan(BigInt[], BigInt[]) AS
        for i in size($1)
        DO
            update s.t1
            SET c3 = $2[$i]
            WHERE c2 = $1[$i]
        END FOR

In this prepared statement I am just trying to explain the algorithm.
I do not know the exact syntax.

Sorry for the confusion.

Thanks
Shankha Banerjee


On Fri, Jul 1, 2016 at 10:48 AM, Adrian Klaver
<adrian.klaver@aklaver.com> wrote:
> 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.klaver@aklaver.com