Question

I am running into a slight problem in Oracle SQL.

I have a table that has the following columns
(ID, AttributeID, AttributeValue, Version).

I would like to query the table for the latest version given an attribute id.

For example, if I have the following data

ID AttrId AttrValue Version
1  1      A         1 
1  1      B         2 
1  1      C         3
2  1      F         1
2  2      G         1

If I decided to filter by attribute id 1, I would like to get

ID AttrId AttrValue Version
1  1      C         3
2  1      F         1

The query will be very simple if I supply the id, because I can filter first
by the ID and AttributeID, and then find the max for the version column.

However, I am still looking and thinking of a solution when the ID is not given, and
would like to just get a list based on the AttributeID only.

Any tips would help greatly!

thanks!

Answer 1

Would this help?

select * from attributes a
where attribute_id := given_attribute_id
and version_id = (
 select max( version_id ) from attributes b
where attribute_id := given_attibute_id 
and b.id = a.id 

)