Here are a couple of suggestions. First thing is that LMAX(list of dates) will give you the greatest date, not the oldest.
Regardless of what you are looking for, you need to determine what the most extreme date in your data is. Set a variable for that value and then substitute it in Buddy’s formula. Except for numbers with ZERO ON, NULL values can’t be used in any calculations or logical test because R:Base doesn’t know what the value is. E.g. comparing ‘text value’ to NULL always results in FALSE. Is ‘fred’ less than, greater than or equal to NULL? Regards, Stephen Markson The Pharmacy Examining Board of Canada 416.979.2431 x251 From: 'Patti Jakusz' via RBASE-L [mailto:[email protected]] Sent: February-14-17 6:37 PM To: [email protected] Subject: Re: [RBASE-L] - problem with null values Thank you, Jan. ________________________________ From: jan johansen <[email protected]<mailto:[email protected]>> To: [email protected]<mailto:[email protected]> Sent: Tuesday, February 14, 2017 5:16 PM Subject: RE: [RBASE-L] - problem with null values Patti, Buddy beat me to it but sometimes when we are using an older database, we actually saved a space for a null so you may need to check to see if you actually have nulls. Jan -----Original Message----- From: "Buddy Walker" <[email protected]<mailto:[email protected]>> To: <[email protected]<mailto:[email protected]>> Date: Tue, 14 Feb 2017 17:11:14 -0500 Subject: RE: [RBASE-L] - problem with null values Patti You might want to try something like this depending on how you want to hand null dates. It my example I’m saying if date is null then make it 12/31/2999 or whatever date you want. …. OldestDate = (LMAX((IFNULL(DATE1,12/31/2999,DATE1)),(IFNULL(DATE2,12/31/2999,DATE2)),(IFNULL(DATE3,12/31/2999,DATE3)))) I didn’t test this so make sure to test on a copy of database Buddy From: 'Patti Jakusz' via RBASE-L [mailto:[email protected]] Sent: Tuesday, February 14, 2017 3:38 PM To: [email protected]<mailto:[email protected]>; RBASE-L <[email protected]<mailto:[email protected]>>; RBASE-L <[email protected]<mailto:[email protected]>> Subject: [RBASE-L] - problem with null values Hello, I'm using Rbase 10. I'm trying to update one date column in my table to be the oldest of 3 other date columns. My command is: update Table1 set OldestDate = (LMAX(date1, date2, date3)) But it only works if all three dates have values. I have zero set on. I tried setting on Eqnull. But I only get a blank if one of the dates is null. Is there another setting to turn on? Thanks, Patti -- You received this message because you are subscribed to the Google Groups "RBASE-L" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]<mailto:[email protected]>. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "RBASE-L" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]<mailto:[email protected]>. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "RBASE-L" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]<mailto:[email protected]>. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "RBASE-L" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]<mailto:[email protected]>. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "RBASE-L" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
