Question:
I have a table with a datefield as part of the key. This was needed because it stores historical information. I need to know how to write an SQL query that will supress all records except those with the “latest” date.

The other part of the key is a field named “Trailer Number”. I only need to see the trailers with the latest dates (because there are multiple entries for each trailer).

Answer:
You need to apply the MAX function to the date while using the table twice. You can accomplish this by having a self-referencing query using the table twice (MyTable A, MyTable B) or by making a subquery in the WHERE Clause.

(WHERE DATE > (SELECT MAX(DATE) FROM MyTable)