Morning Walter,

>> I have a table MOVIMCAB (Movim_ID, Movim_Date)
>> and a table MOVIMDET (Movim_ID, Product_Code, Product_Count)
>> both tables can be relationated by the Movim_ID column
>>
>> How can I to know which is the Product_Count of the last date?
>>
>> MOVIMCAB
>> ------------------------
>> 1 01/01/2010
>> 2 02/02/2010
>> 3 06/03/2010
>>
>> MOVIMDET
>> -----------------------
>> 1 501 20
>> 2 501 12
>> 3 501 15
>>
>> I want to get 15, because it is the Product_Count of the last date.

select product_count
from movimdet
where movim_id = (
select movim_id
from movimcab
where movim_date = (
select max(movim_date)
from movimcab
)
);

I would advise adding a descending index to the movim_date column in
movimcab to make extracting the maximum date much easier as data volumes
increase.

One question, although you have the movim_id in each table, movimdet
also has product codes. I assume that there will be other products and
not just product 501? If so, is the following a decent data set for your
needs where another product code is in use?

MOVIMDET
-----------------------
1 101 02
1 501 20
2 101 12
2 501 20
3 101 202
3 501 15

If so, then my query above will require the product_code adding to the
list of selected columns on the first line:

select product_code,product_count
from movimdet
where movim_id = (
select movim_id
from movimcab
where movim_date = (
select max(movim_date)
from movimcab
)
);

PRODUCT_CODE PRODUCT_COUNT
--------------------------
101 202
501 15


And, if you had a movimdesc table holding product_code and
product_descriptions, the following would also be helpful:

MOVIMDESC
-----------
101 Widget
501 Thermo-nuclear device

select d.product_desc,n.product_count
from movimdet n
join movimdesc d on (d.product_code = n.product_code)
where movim_id = (
select movim_id
from movimcab
where movim_date = (
select max(movim_date)
from movimcab
)
);

I'd have a unique ascending index on product_desc in this table.

PRODUCT_DESC PRODUCT_COUNT
--------------------------
Widget 202
Thermo-nuclear device 15


HTH

Cheers,
Norman.

Norman Dunbar
Contract Senior Oracle DBA
Capgemini Database Team (EA)
Internal : 7 28 2051
External : 0113 231 2051


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