historical lookup query

I'm having a dickins of a time with a particular query and am hoping
someone here can help me.
Using the following example;
declare @.SearchDate datetime
set @.SearchDate = '30 Nov 2005'
declare @.t1 table (t1id int, t1desc varchar(10))
insert into @.t1 (t1id, t1desc) values (1, 'Ed')
insert into @.t1 (t1id, t1desc) values (2, 'Bill')
insert into @.t1 (t1id, t1desc) values (3, 'Bob')
insert into @.t1 (t1id, t1desc) values (4, 'Fred')
insert into @.t1 (t1id, t1desc) values (5, 'John')
declare @.t1history table (t1id int, t1desc varchar(10), created
datetime)
insert into @.t1history (t1id, t1desc, created) values (1, 'James', '01
Jan 2005')
insert into @.t1history (t1id, t1desc, created) values (1, 'Frank', '05
Jan 2005')
insert into @.t1history (t1id, t1desc, created) values (1, 'Henry', '10
May 2005')
insert into @.t1history (t1id, t1desc, created) values (1, 'Joe', '28
Nov 2005')
insert into @.t1history (t1id, t1desc, created) values (4, 'Toby', '21
Oct 2005')
insert into @.t1history (t1id, t1desc, created) values (4, 'Brian', '25
Oct 2005')
insert into @.t1history (t1id, t1desc, created) values (4, 'Horace', '28
Nov 2005')
insert into @.t1history (t1id, t1desc, created) values (5, 'Ben', '21
Oct 2005')
declare @.lookup table (val varchar(10))
insert into @.lookup (val) values ('Ben')
insert into @.lookup (val) values ('Frank')
insert into @.lookup (val) values ('Bill')
--example query
select *,
(select top 1 t1desc from @.t1history as Table1History where
Table1History.t1id = Table1.t1Id and created <= @.SearchDate +1 order by
created desc) as t1deschistory
from @.t1 as Table1
I want to filter the results returned from @.t1 against those contained
in @.lookup
I also need to be able to filter the results based on what the value
for t1desc could have been in the past using @.t1history and @.SearchDate
For example, with the date of '30 Nov 2005' I would expect the
following;
t1id t1desc t1deschistory
----
2 'Bill' null
5 'John' 'Ben'
Changing the date to '15 Oct 2005' I would expect;
t1id t1desc t1deschistory
----
2 'Bill' null
and changing it again to '15 Jan 2005' I would expect;
t1id t1desc t1deschistory
----
1 'Ed' 'Frank'
2 'Bill' null
What I basically want to do is this;
select *,
(select top 1 t1desc from @.t1history as Table1History where
Table1History.t1id = Table1.t1Id and created <= @.SearchDate +1 order by
created desc) as t1deschistory
from @.t1 as Table1
where t1desc in (select val from @.lookup) or t1deschistory in (select
val from @.lookup)
This gives the following error as expected;
Server: Msg 207, Level 16, State 3, Line 28
Invalid column name 't1deschistory'.
Moving the sub-query into a join doesn't work either;
select *
from @.t1 as Table1
left join (select top 1 * from @.t1history as t1history where
t1history.t1id = Table1.t1Id and created <= @.SearchDate +1 order by
created desc) Table1History on Table1.t1id = Table1History.t1Id
where Table1.t1desc in (select val from @.lookup) or
Table1History.t1desc in (select val from @.lookup)
This gives the following error;
Server: Msg 107, Level 16, State 2, Line 28
The column prefix 'Table1' does not match with a table name or alias
name used in the query.
Can anyone help?
Many thanks in advance,
Edone way: make it a derived table before applying the where e.g.
select * from (
select *,
(select top 1 t1desc
from @.t1history as Table1History
where Table1History.t1id = Table1.t1Id
and created <= @.SearchDate +1
order by created desc) as t1deschistory
from @.t1 as Table1
) x
where t1desc in (select val from @.lookup) or t1deschistory in (select
val from @.lookup)
ThievingScouser wrote:
> I'm having a dickins of a time with a particular query and am hoping
> someone here can help me.
> Using the following example;
> declare @.SearchDate datetime
> set @.SearchDate = '30 Nov 2005'
> declare @.t1 table (t1id int, t1desc varchar(10))
> insert into @.t1 (t1id, t1desc) values (1, 'Ed')
> insert into @.t1 (t1id, t1desc) values (2, 'Bill')
> insert into @.t1 (t1id, t1desc) values (3, 'Bob')
> insert into @.t1 (t1id, t1desc) values (4, 'Fred')
> insert into @.t1 (t1id, t1desc) values (5, 'John')
> declare @.t1history table (t1id int, t1desc varchar(10), created
> datetime)
> insert into @.t1history (t1id, t1desc, created) values (1, 'James', '01
> Jan 2005')
> insert into @.t1history (t1id, t1desc, created) values (1, 'Frank', '05
> Jan 2005')
> insert into @.t1history (t1id, t1desc, created) values (1, 'Henry', '10
> May 2005')
> insert into @.t1history (t1id, t1desc, created) values (1, 'Joe', '28
> Nov 2005')
> insert into @.t1history (t1id, t1desc, created) values (4, 'Toby', '21
> Oct 2005')
> insert into @.t1history (t1id, t1desc, created) values (4, 'Brian', '25
> Oct 2005')
> insert into @.t1history (t1id, t1desc, created) values (4, 'Horace', '28
> Nov 2005')
> insert into @.t1history (t1id, t1desc, created) values (5, 'Ben', '21
> Oct 2005')
> declare @.lookup table (val varchar(10))
> insert into @.lookup (val) values ('Ben')
> insert into @.lookup (val) values ('Frank')
> insert into @.lookup (val) values ('Bill')
> --example query
> select *,
> (select top 1 t1desc from @.t1history as Table1History where
> Table1History.t1id = Table1.t1Id and created <= @.SearchDate +1 order by
> created desc) as t1deschistory
> from @.t1 as Table1
>
> I want to filter the results returned from @.t1 against those contained
> in @.lookup
> I also need to be able to filter the results based on what the value
> for t1desc could have been in the past using @.t1history and @.SearchDate
> For example, with the date of '30 Nov 2005' I would expect the
> following;
> t1id t1desc t1deschistory
> ----
> 2 'Bill' null
> 5 'John' 'Ben'
> Changing the date to '15 Oct 2005' I would expect;
> t1id t1desc t1deschistory
> ----
> 2 'Bill' null
> and changing it again to '15 Jan 2005' I would expect;
> t1id t1desc t1deschistory
> ----
> 1 'Ed' 'Frank'
> 2 'Bill' null
>
> What I basically want to do is this;
> select *,
> (select top 1 t1desc from @.t1history as Table1History where
> Table1History.t1id = Table1.t1Id and created <= @.SearchDate +1 order by
> created desc) as t1deschistory
> from @.t1 as Table1
> where t1desc in (select val from @.lookup) or t1deschistory in (select
> val from @.lookup)
> This gives the following error as expected;
> Server: Msg 207, Level 16, State 3, Line 28
> Invalid column name 't1deschistory'.
> Moving the sub-query into a join doesn't work either;
> select *
> from @.t1 as Table1
> left join (select top 1 * from @.t1history as t1history where
> t1history.t1id = Table1.t1Id and created <= @.SearchDate +1 order by
> created desc) Table1History on Table1.t1id = Table1History.t1Id
> where Table1.t1desc in (select val from @.lookup) or
> Table1History.t1desc in (select val from @.lookup)
> This gives the following error;
> Server: Msg 107, Level 16, State 2, Line 28
> The column prefix 'Table1' does not match with a table name or alias
> name used in the query.
>
> Can anyone help?
> Many thanks in advance,
> Ed
>