Re: Problem in getting running total with group by

[Rick James]

* Don't use VARCHAR for dates and time.
* Use DATETIME, not VARCHAR
* Use a single column (of datatype DATETIME or TIMESTAMP) with both DATE and TIME, not two columns.
* Garbage in, garbage out: '09:60:10' -> '0.416782407'

1 01-01-2013 10:40:10 Entry 1 1 1
1 02-01-2013 09:30:10 Entry 1 2 1
(@runtot := a.flag + @runtot) AS rt, ( @runtot := a.flag ) ne
seems correct. Details:

1 01-01-2013 10:40:10 Entry 1 (@runtot := a.flag + @runtot)->1 @runtot := a.flag->1
That is, @runtot is set to 1 from arithmetic, then it is set to 1 from a.flag.

1 02-01-2013 09:30:10 Entry 1 (@runtot := a.flag + @runtot)->2 @runtot := a.flag->1
First @runtot := 1 + 1 = 2, then $runtot is set back to 1.

The rt column (1, then 2) seems correct as a "running total".

The rt column:
(@runtot := a.flag + @runtot)
could be simplified to just
a.flag + @runtot

Perhaps the problem is that you are counting a.flag twice? Once in the current line, then again as the initial value of @runtot?

Or, if you really mean "running total", you should get rid of the "ne" column, which resets @runtot.