MySQL选择第一次出现条件匹配

Question

Id      | Price
----------------
1       | 10
2       | 20
3       | 40
4       | 10

I need to select ids where first occurrence of summation of price is greater than or equal 55 matching from the bottom. At this case -- I will have 4,3,2 ids selected.

Answer 1

Well, this is kinda tricky for MySQL since it doesn't support any window fuctions and becuase you want to include the first occurrence as well. You can try this:

SELECT * FROM (
    SELECT t.id,
           (SELECT sum(s.price) FROM YourTable s
            WHERE s.id <= t.id) as cuml_sum
    FROM YourTable t) ss
WHERE ss.cuml_sum < 55
--Will select all the record will the sum < 55
UNION ALL
SELECT * FROM (
    SELECT t.id,
           (SELECT sum(s.price) FROM YourTable s
            WHERE s.id <= t.id) as cuml_sum
    FROM YourTable t) tt
WHERE tt.cuml_sum >= 55
ORDER BY tt.cuml_sum 
LIMIT 1
--Will select the first record that have sum >= 55