MySQL - How to SELECT based on value of another SELECT

Question

I have a table that looks something like this:

Name    Year   Value
 A      2000     5
 A      2001     3
 A      2002     7
 A      2003     1
 B      2000              


        

Answer 1

You can calculate the total (and from that the desired percentage) by using a subquery in the FROM clause:

SELECT Name,
       SUM(Value) AS "SUM(VALUE)",
       SUM(Value) / totals.total AS "% of Total"
FROM   table1,
       (
           SELECT Name,
                  SUM(Value) AS total
           FROM   table1
           GROUP BY Name
       ) AS totals
WHERE  table1.Name = totals.Name
AND    Year BETWEEN 2000 AND 2001
GROUP BY Name;

Note that the subquery does not have the WHERE clause filtering the years.