MySQL query to sum all distinct values

Question

I have a table:

uid_from uid_to count
   x1      x2    3 
   x3      x2    5
   x8      x1    99
   x9      x1    1

And would like to generate a summ table like this:

uid_to   sum
  x1     100
  x2      8

I can do it in PHP, but would rather do it directly in a MySQL query. I should note the table has 700 Million rows.

Why does the title to your question say "all distinct values"? — eggyal
– eggyal, Commented Nov 12, 2012 at 17:19
@eggyal cuz I wanna sum all the distinct uid_to values. Thought about the problem wrong. — Noam
– Noam, Commented Nov 12, 2012 at 17:20

juergen d · Accepted Answer · 2012-11-12 17:17:26Z

3

select uid_to, sum(count) as sum
from your_table
group by uid_to

answered Nov 12, 2012 at 17:17

juergen d

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2 Comments

thanks. do you think this will end in within a reasonable time?

Yes. If not take a look at the indexes of your table.