Summing in mysql previous row with current

Question

Need help to make query. I have table like this:

kli, akt, mes

'2', '2',  '201209'

'2', '2',  '201210'

'3', '3',  '201211'

And I need a result table:

kli, akt, mes

'2', '2',  '201209'

'4', '4',  '201210'

'7', '7',  '201211'

result tables sum by field mes, current and all previous rows

Answer 1

试试下面的查询

SELECT SUM(b.kli),SUM(b.akt),a.mes FROM tableName a INNER JOIN tableName b ON a.mes >= b.mes GROUP BY a.mes