HOW to "Sum" in one field??

[harris97]

Let's say i ha this table:

ID | Bytes |
1 | 21 |
2 | 8 |
3 | 4 |

My question is how to sum (21+8+4) in field "Bytes" so the output will be 32. I don't about "sum" function in mysql or php.

Thanks for the answer

[parena]

SELECT SUM(Bytes) FROM table_name;

Easy, isn't it? 🙂

[chowdary]

Hi,
You can use the query
$qry="select sum(Bytes) bytes_sum from $tablename";
Here bytes_sum will become the field name i.e you have to use $row["bytes_sum"]
inorder to get the sum(i am assuming that you are using while($row=mysql_fetch_array($res)).
Note that you can't select any other data if you use that query.
If you need to select the other data also then i think the only option you are left with is sum the values in while loop.
ex: while($row=mysql_fetch_array($res))
{
$bytes_sum=$bytes_sum+$row["Bytes"];
}

Hope this helps.