How to do a sum of previous rows in mysql a sum of previous rows -

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this question has answer here:

first of sorry english

i try find requete calculate sum of values in different rows :

row1    result 2          2 5          7 7          14

assuming first row defines ordering, can correlated subquery:

select r.row1,        (select sum(t2.row1) requete r2 r2.row1 <= r.row1) cumesum requete r;

for larger table, might inefficient, , variables improve performance:

select r.row1,        (@sum := @sum + r.row1) cumesum requete r cross join      (@sum := 0) params order r.row1;

note in both cases column used ordering rows not need same column cumulative sum calculation.


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