Help with calcluated columns

[Evan Stockdale]

Hi all,

I'm very new to MySQL.

I'm working on converting MS Access queries to MySQL. So far, I've been having good luck with it but I'm running into trouble with converting the below listed calculated columns in Access to MySQL:

1) IIf(sumofpacking Is Null,Bags,Bags-sumofpacking) AS Bags_Undelivered

2) DateDiff('m', DELVPERIOD_TO, Date()) AS Months_Late

3) Round((0.025*Lbs Undelivered*Months Late),2) AS Store_Fin_Charges


I tried converting the IIf statement to a Case statement in MySQL but no luck.

CASE SumOfPACKING
WHEN SumOfPACKING ISNULL THEN Bags
ELSE Bags-SumOfPACKING
END AS BAGS_UNDELIVERED

Any help is appreciated.