SQL - Select unique rows from a group of results

Question

I have wrecked my brain on this problem for quite some time. I\'ve also reviewed other questions but was unsuccessful.

The problem I have is, I have a list of results/t

Answer 1

This should work in MySQL:

SELECT registration, id, date, unittype FROM 
  (SELECT registration AS temp_reg, MAX(date) as temp_date 
  FROM table_name GROUP BY registration) AS temp_table
WHERE registration=temp_reg and date=temp_date

The idea is to use a subquery in a FROM clause which throws up a single row containing the correct date and registration (the fields subjected to a group); then use the correct date and registration in a WHERE clause to fetch the other fields of the same row.