Re: Accumulated Sum

[Jay Pipes]

Yes. Join the table to itself using the >= operator in the ON expression. The second result set can be SUMmed to provide the aggregated totals, like so:

Assume:

CREATE TABLE some_table (
some_date DATETIME NOT NULL
, some_quantity INT NOT NULL
, PRIMARY KEY (some_date)
);

you can get the report you requested like so:

SELECT t1.some_date, t1.some_quantity, SUM(t2.quantity) as "Rolling Sum"
FROM some_table t1
INNER JOIN some_table t2
ON t1.some_date >= t2.some_date;

Jay Pipes
Community Relations Manager, North America, MySQL Inc.

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