mysql列值累加,SQL-列中的值累加

How can I add up values in a SQL column? I have the table set up in xampp and I'm trying to add up all the values in a column titled "gross".

解决方案

SQL Server or MySQL:

select sum(MyColumn) as MyColumnSum from MyTable

If you need to sum a column by a grouping of another column

select sum(MyColumn) as MyColumnSum, OtherColumn from MyTable Group By OtherColumn

Here is a way to, separately, add up negative or positive numbers

select

sum( case when MyColumn < 0 then MyColumn else 0 end ) as NegativeSum,

sum( case when MyColumn > 0 then MyColumn else 0 end ) as PositiveSum

from

MyTable

Reference