sum(number)

BubikolRamios · 03-02-2013, 12:16 PM

Code:

select sum(111) = 111

now try:

Code:

select sum(111) from xtable
select sum(111) from ytable

any you get some looks like randome numbers.

Any explanation ?

Arcticwarrio · 03-05-2013, 09:54 PM

what is xtable ?

BubikolRamios · 03-05-2013, 10:41 PM

it is any table.

Arcticwarrio · 03-05-2013, 11:07 PM

its the number of entrys 3 times eg if you have 51 rows it will output 515151

Arcticwarrio · 03-05-2013, 11:10 PM

or not, 4 rows = 444

31 rows = 3441

so its 111 * rows

Old Pedant · 03-05-2013, 11:32 PM

Correct. 55 rows would be 5661.

It's easy to see this, Bubikol, if you do

Code:

SELECT COUNT(*), SUM(111) FROM xtable

What you are telling SQL (any SQL, not just MySQL) to do is to add 111 to the sum for each row in the table.

Think about it: If you do

Code:

SELECT SUM(someField) FROM xtable

all that tells SQL to do is to add the value of field someField to the sum for each row in the table. So when you use a constant, instead, it is the constant that gets added for each row.

Nothing "random" about it.