Query with no records returns null for SUM function

Question

This query will return you 0 records if no records exist in TableA:

Select strA, strB, intC, floatD, from tableA

However, this query returns 1 records with all columns as Null.

Select strA, strB, intC, floatD, sum(intC+intD) as sumE,
from tableA

So, to fix it, I did:

Select strA, strB, intC, floatD, sum(intC+intD) as sumE,
from tableA
having sumE is not null

I was wondering if there is a better way to do the same thing. Any in-built MySQL function that can do the same thing?

Tom H · Accepted Answer · 2016-03-29 20:44:12Z

3

That's because you don't have a GROUP BY. You're asking MySQL to get you the SUM of intC + intD for the entire table, so it's going to give you a result no matter what. It has to put in something for strA, strB, etc. so it puts in NULL values.

For example, just do SELECT SUM(intA) FROM tableA and you'll get NULL.

answered Mar 29, 2016 at 20:44

Tom H

47.6k15 gold badges90 silver badges134 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Query with no records returns null for SUM function

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related