Beast Mode Help: Two layers of division

I've got a calculation I am trying to perform with a beast mode formula, that I can't get to work.

The calculation is (Number of Lines / Hours Active) / Standard

I'm trying to protect against divide by zero in the two layers of the formula. The first item in the order of operation is the (Number of Lines / Hours Active), then the result of that calculation is / Standard

Here is the beast mode I attempted, but is not working. I know this case is checking for NULL, do I need to check for zero as well?

CASE
WHEN IFNULL(SUM(`RCV Standard - Dynamic`),0)=0
THEN 0
ELSE

(CASE
WHEN IFNULL(SUM(`RCV Time Active`),0)=0
THEN 0
ELSE

(SUM(`RCV Number of Lines`)/SUM(`RCV Time Active`))/`RCV Standard - Dynamic`

END)
END

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Accepted answers

BCorless

@swagner

Another option is to do a nested CASE statement to account for the divide by zero in both divisors:

CASE
WHEN IFNULL(`Standard`,0) = 0 THEN 0
ELSE

(CASE
WHEN IFNULL(`Hours Active`,0) = 0 THEN 0
ELSE (IFNULL(Number of Lines,0) / IFNULL(Hours Active,0))
END) / IFNULL(`Standard`,0)

END

All comments

Tomo

Hi.
Please try using nullif and ifnull.

Original

(Number of Lines / Hours Active) / Standard

Standard = 0 -> null

(Number of Lines / Hours Active) / nullif(Standard,0)

0 or null -> 0

ifnull((Number of Lines / Hours Active) / nullif(Standard,0),0)

swagner

I've tried a few times without success to change my existing Beast Mode to include what you've suggested and I cannot get it to work. Can you show me the completed Beast Mode instead of just those suggested lines please?

RGranada

Hi @swagner,

If I correctly understood your problem... Have you tried using just nullif? Divisions by 0 do raise an error but division by null equals null (This is what I systematically use), so in your case, I would go with :

(Number of Lines / NULLIF(Hours Active,0)) / NULLIF(Standard,0)

This way no divisor will ever be zero.

In the end, you can always revert to zero if the result is null (I do not agree with this approach as a division by zero tends to an infinite number, not a zero! But some people follow this)

IFNULL((Number of Lines / NULLIF(Hours Active,0)) / NULLIF(Standard,0),0)

Hope this helps.

BCorless

@swagner

Another option is to do a nested CASE statement to account for the divide by zero in both divisors:

CASE
WHEN IFNULL(`Standard`,0) = 0 THEN 0
ELSE

(CASE
WHEN IFNULL(`Hours Active`,0) = 0 THEN 0
ELSE (IFNULL(Number of Lines,0) / IFNULL(Hours Active,0))
END) / IFNULL(`Standard`,0)

END

Tomo

I forgot to nullif to "Hours Active".

Original
(Number of Lines / Hours Active) / Standard

Standard = 0 -> null
(Number of Lines / nullif(Hours Active,0)) / nullif(Standard,0)
or
(sum(Number of Lines) / nullif(sum(Hours Active),0)) / nullif(sum(Standard),0)

0 or null -> 0
ifnull((Number of Lines / nullif(Hours Active,0)) / nullif(Standard,0),0)
or
ifnull((sum(Number of Lines) / nullif(sum(Hours Active),0)) / nullif(sum(Standard),0),0)