Sum values of a single row?

Question

I have a MySQL query that returns a single row that is a series of 1s and 0s. It\'s for a progress bar indicator. I have the summing of it in code now, but I tried to sum th

Answer 1

You can't really do it any simpler than:

SELECT item_1 + item_2 + item_3 + item_4
FROM Table1

If you have a lot of columns then it will take a while to type in. I guess it took quite a long time to create the table too.

In future design your tables differently so that each stage of the process is a row not a column. In other words, instead of this:

id, item_1, item_2, item_3, item_4

Your table could look like this:

id, item_number, value

And then you can query it like this:

SELECT SUM(value)
FROM Table1
WHERE id = @id

In fact, you probably don't even need the value column. The presence or absence of the row is enough information. So your query becomes:

SELECT COUNT(*)
FROM Table1
WHERE id = @id

It's perhaps a bit late for you this time, but if you still have a chance to change the design, then it might be worth considering this.

Answer 2

select item_1 + item_2 + item_3 + item_4 as ItemSum
from MyTable

If there can be null values, you'll need to handle them like this:

select ifnull(item_1, 0) + ifnull(item_2, 0) + ifnull(item_3, 0) + ifnull(item_4, 0) as ItemSum
from MyTable