USE tpch1;
drop table if exists visit;
drop table if exists client;
create table visit (id_client integer,nb_event integer,update_date datetime, visit_date datetime) engine=columnstore;
create table client (id_client integer,id_event integer,event_date datetime) engine=columnstore;
insert into visit values (1,0,NULL,"2010-09-08");
insert into visit values (2,0,NULL,"2010-09-08");
insert into visit values (2,0,NULL,"2010-09-10");
insert into visit values (3,0,NULL,"2010-09-08");
insert into visit values (3,0,NULL,"2010-09-10");
insert into client values (1,20,"2010-09-07");
insert into client values (1,21,"2010-09-07");
insert into client values (1,22,"2010-09-07");
insert into client values (2,23,"2010-09-07");
insert into client values (2,24,"2010-09-07");
insert into client values (2,25,"2010-09-10");
insert into client values (3,29,"2010-09-10");
select * from
visit V,
(
SELECT
CL.id_client,
COUNT(CL.id_event) as nb_event
FROM
client CL
WHERE
CL.event_date < "2010-09-10"
GROUP BY
CL.id_client
) Res
WHERE
V.visit_date ="2010-09-08"
AND V.id_client = Res.id_client order by 1, 2, 3;
id_client	nb_event	update_date	visit_date	id_client	nb_event
1	0	NULL	2010-09-08 00:00:00	1	3
2	0	NULL	2010-09-08 00:00:00	2	2
UPDATE
visit V,
(
SELECT
CL.id_client,
COUNT(CL.id_event) as nb_event
FROM
client CL
WHERE
CL.event_date < "2010-09-10"
GROUP BY
CL.id_client
) Res
SET 
V.nb_event = Res.nb_event,
V.update_date = '2010-12-11'
WHERE
V.visit_date ="2010-09-08"
AND V.id_client = Res.id_client;
select * from
visit V,
(
SELECT
CL.id_client,
COUNT(CL.id_event) as nb_event
FROM
client CL
WHERE
CL.event_date < "2010-09-10"
GROUP BY
CL.id_client
) Res
WHERE
V.visit_date ="2010-09-08"
AND V.id_client = Res.id_client order by 1, 2, 3;
id_client	nb_event	update_date	visit_date	id_client	nb_event
1	3	2010-12-11 00:00:00	2010-09-08 00:00:00	1	3
2	2	2010-12-11 00:00:00	2010-09-08 00:00:00	2	2
drop table if exists visit;
drop table if exists client;