Thread: how to implement add using upsert and trigger?

how to implement add using upsert and trigger?

From
"yin.zhb@163.com"
Date:
Hi, all:
  when I using upsert and trigger to update other table automatically:
create table stat_detail(itemid bigint not null, value bigint, captime bigint);
create table stat_result(itemid bigint primary key, value bigint, cnt bigint);

create or replace function inertfunc() returns trigger as $$
begin
    insert into stat_result(itemid,value,cnt) values(new.itemid, new.value, 1)
    on conflict(itemid) do update
    set value = excluded.value + new.value, cnt = excluded.cnt +1 where excluded.itemid = new.itemid;
    return new;
end;
$$
language plpgsql;

create trigger tri_insert after insert on stat_detail for each row execute function inertfunc();

postgres=# insert into stat_detail values(100,1,1);
INSERT 0 1
postgres=# select * from stat_result ;
 itemid | value | cnt
--------+-------+-----
    100 |     1 |   1
(1 row)

postgres=# insert into stat_detail values(100,1,1);
INSERT 0 1
postgres=# select * from stat_result ;
 itemid | value | cnt
--------+-------+-----
    100 |     2 |   2
(1 row)

postgres=# insert into stat_detail values(100,1,1);
INSERT 0 1
postgres=# select * from stat_result ;
 itemid | value | cnt
--------+-------+-----
    100 |     2 |   2
(1 row)


But  I want it is "100 3 3". So how I can do?


yin.zhb@163.com

Re: how to implement add using upsert and trigger?

From
Dominique Devienne
Date:
On Mon, Nov 28, 2022 at 1:37 PM yin.zhb@163.com <yin.zhb@163.com> wrote:
>     on conflict(itemid) do update
>     set value = excluded.value + new.value, cnt = excluded.cnt +1 where excluded.itemid = new.itemid;

OT, but isn't `where excluded.itemid = new.itemid` redundant, given
`on conflict(itemid)`?
I'm asking more because I'm not sure, for my own education. Thanks, --DD



Re: Re: how to implement add using upsert and trigger?

From
"yin.zhb@163.com"
Date:
em, which is does not matter

yin.zhb@163.com
 
Date: 2022-11-28 20:47
Subject: Re: how to implement add using upsert and trigger?
On Mon, Nov 28, 2022 at 1:37 PM yin.zhb@163.com <yin.zhb@163.com> wrote:
>     on conflict(itemid) do update
>     set value = excluded.value + new.value, cnt = excluded.cnt +1 where excluded.itemid = new.itemid;
 
OT, but isn't `where excluded.itemid = new.itemid` redundant, given
`on conflict(itemid)`?
I'm asking more because I'm not sure, for my own education. Thanks, --DD
 

Re: how to implement add using upsert and trigger?

From
Pavel Luzanov
Date:
Hi, I think you need:

    insert into stat_result(itemid,value,cnt) values(new.itemid, new.value, 1)
    on conflict(itemid) do update
    set value = stat_result.value + new.value, cnt = stat_result.cnt +1;

excluded.value and new.value is the same value from inserted record, but your need a current value from stat_result.

On 28.11.2022 15:37, yin.zhb@163.com wrote:
body { line-height: 1.5; }body { font-size: 14px; font-family: 微软雅黑; color: rgb(0, 0, 0); line-height: 1.5; }
Hi, all:
  when I using upsert and trigger to update other table automatically:
create table stat_detail(itemid bigint not null, value bigint, captime bigint);
create table stat_result(itemid bigint primary key, value bigint, cnt bigint);
create or replace function inertfunc() returns trigger as $$
begin
    insert into stat_result(itemid,value,cnt) values(new.itemid, new.value, 1)
    on conflict(itemid) do update
    set value = excluded.value + new.value, cnt = excluded.cnt +1 where excluded.itemid = new.itemid;
    return new;
end;
$$
language plpgsql;
create trigger tri_insert after insert on stat_detail for each row execute function inertfunc();
postgres=# insert into stat_detail values(100,1,1);
INSERT 0 1
postgres=# select * from stat_result ;
 itemid | value | cnt
--------+-------+-----
    100 |     1 |   1
(1 row)
postgres=# insert into stat_detail values(100,1,1);
INSERT 0 1
postgres=# select * from stat_result ;
 itemid | value | cnt
--------+-------+-----
    100 |     2 |   2
(1 row)
postgres=# insert into stat_detail values(100,1,1);
INSERT 0 1
postgres=# select * from stat_result ;
 itemid | value | cnt
--------+-------+-----
    100 |     2 |   2
(1 row)

But  I want it is "100 3 3". So how I can do?



-- 
Pavel Luzanov
Postgres Professional: https://postgrespro.com
The Russian Postgres Company

Re: Re: how to implement add using upsert and trigger?

From
"yin.zhb@163.com"
Date:
Thank you, this result is what I want


yin.zhb@163.com
 
Date: 2022-11-28 21:26
Subject: Re: how to implement add using upsert and trigger?
Hi, I think you need:

    insert into stat_result(itemid,value,cnt) values(new.itemid, new.value, 1)
    on conflict(itemid) do update
    set value = stat_result.value + new.value, cnt = stat_result.cnt +1;

excluded.value and new.value is the same value from inserted record, but your need a current value from stat_result.

On 28.11.2022 15:37, yin.zhb@163.com wrote:
Hi, all:
  when I using upsert and trigger to update other table automatically:
create table stat_detail(itemid bigint not null, value bigint, captime bigint);
create table stat_result(itemid bigint primary key, value bigint, cnt bigint);
create or replace function inertfunc() returns trigger as $$
begin
    insert into stat_result(itemid,value,cnt) values(new.itemid, new.value, 1)
    on conflict(itemid) do update
    set value = excluded.value + new.value, cnt = excluded.cnt +1 where excluded.itemid = new.itemid;
    return new;
end;
$$
language plpgsql;
create trigger tri_insert after insert on stat_detail for each row execute function inertfunc();
postgres=# insert into stat_detail values(100,1,1);
INSERT 0 1
postgres=# select * from stat_result ;
 itemid | value | cnt
--------+-------+-----
    100 |     1 |   1
(1 row)
postgres=# insert into stat_detail values(100,1,1);
INSERT 0 1
postgres=# select * from stat_result ;
 itemid | value | cnt
--------+-------+-----
    100 |     2 |   2
(1 row)
postgres=# insert into stat_detail values(100,1,1);
INSERT 0 1
postgres=# select * from stat_result ;
 itemid | value | cnt
--------+-------+-----
    100 |     2 |   2
(1 row)

But  I want it is "100 3 3". So how I can do?



-- 
Pavel Luzanov
Postgres Professional: https://postgrespro.com
The Russian Postgres Company