SQL Where In clause with multiple fields

Question

I have a table as below.

id          date         value

1           2011-10-01   xx

1           2011-10-02   xx
...

1000000     2011-10-01   xx

Then I have 1000 ids each associates with a date. I would like to perform something as below:

SELECT id, date, value
FROM the table
WHERE (id, date) IN ((id1, <= date1), (id2, <= date2), (id1000, <= date1000))

What's the best way to achieve above query?

Answer 1

You didn't specify your DBMS, so this is standard SQL.

You could do something like this:

with list_of_dates (id, dt) as (
  values 
     (1, date '2016-01-01'), 
     (2, date '2016-01-02'),
     (3, date '2016-01-03')  
)
select 
from the_table t
  join list_of_dates ld on t.id = ld.id and t.the_date <= ld.dt;

This assumes that you do not have duplicates in the list of dates.

---

Update - now that the DBMS has been disclosed.

For SQL Server you need to change that to:

with list_of_dates (id, dt) as (
  values 
     select 1, cast('20160101' as datetime) union all
     select 2, cast('20160102' as datetime) union all
     select 3, cast('20160103' as datetime)
)
select 
from the_table t
  join list_of_dates ld on t.id = ld.id and t.the_date <= ld.dt;

Answer 2

since this is info known ahead of time build a temp table of this info and then join to it

create table #test(id int, myDate date)
insert into #test(id,myDate) values
(1, '10/1/2016'),
(2, '10/2/2016'),
(3, '10/3/2016')

select a.id, a.date, a.value
from table as a
     inner join
     #test as b on a.id=b.id and a.date<=b.myDate