https://communities.sas.com/t5/New-SAS-User/Difference-between-NODUPKEY-and-NODUPRECS/m-p/536246#M6609 <P>I'm wondering if there exists any difference between NODUPKEY and&nbsp; NODUPRECS options ? In my view, they seem totally the same with a BY statement.</P> Sun, 17 Feb 2019 15:32:33 GMT 赵家钧 2019-02-17T15:32:33Z https://communities.sas.com/t5/New-SAS-User/Difference-between-NODUPKEY-and-NODUPRECS/m-p/536246#M6609 <P>I'm wondering if there exists any difference between NODUPKEY and&nbsp; NODUPRECS options ? In my view, they seem totally the same with a BY statement.</P> Sun, 17 Feb 2019 15:32:33 GMT https://communities.sas.com/t5/New-SAS-User/Difference-between-NODUPKEY-and-NODUPRECS/m-p/536246#M6609 赵家钧 2019-02-17T15:32:33Z https://communities.sas.com/t5/New-SAS-User/Difference-between-NODUPKEY-and-NODUPRECS/m-p/536247#M6610 <P>NODUP will delete duplicated observations (records that are identical to each other) while NODUPKEY will delete those observations that have duplicate BY values (the sort BY variables that you name in PROC SORT).</P> <P>Links to SAS papers can be found here<BR /><A href="https://communities.sas.com/t5/SAS-Programming/Difference-between-NOdup-and-NoDupkey/m-p/29490#M66149" target="_blank">https://communities.sas.com/t5/SAS-Programming/Difference-between-NOdup-and-NoDupkey/m-p/29490#M66149</A></P> <P>&nbsp;</P> Sun, 17 Feb 2019 15:38:33 GMT https://communities.sas.com/t5/New-SAS-User/Difference-between-NODUPKEY-and-NODUPRECS/m-p/536247#M6610 VDD 2019-02-17T15:38:33Z https://communities.sas.com/t5/New-SAS-User/Difference-between-NODUPKEY-and-NODUPRECS/m-p/536248#M6611 But..... NODUPRECS option also has a BY statement. Aren't they the same? Sun, 17 Feb 2019 15:45:07 GMT https://communities.sas.com/t5/New-SAS-User/Difference-between-NODUPKEY-and-NODUPRECS/m-p/536248#M6611 赵家钧 2019-02-17T15:45:07Z https://communities.sas.com/t5/New-SAS-User/Difference-between-NODUPKEY-and-NODUPRECS/m-p/536249#M6612 <P>go through this article, it explains everything step by step with examples.</P> <P>&nbsp;</P> <P><A href="https://support.sas.com/resources/papers/proceedings/proceedings/sugi30/037-30.pdf" target="_blank">https://support.sas.com/resources/papers/proceedings/proceedings/sugi30/037-30.pdf</A></P> <P>&nbsp;</P> Sun, 17 Feb 2019 15:45:44 GMT https://communities.sas.com/t5/New-SAS-User/Difference-between-NODUPKEY-and-NODUPRECS/m-p/536249#M6612 kiranv_ 2019-02-17T15:45:44Z https://communities.sas.com/t5/New-SAS-User/Difference-between-NODUPKEY-and-NODUPRECS/m-p/536250#M6613 I think I get the answer just after reading the ABSTRACT!!! Thank you a lot! I just wrongly thought that the BY statement of NODUP can be customized depending on my needs. Sun, 17 Feb 2019 15:50:46 GMT https://communities.sas.com/t5/New-SAS-User/Difference-between-NODUPKEY-and-NODUPRECS/m-p/536250#M6613 赵家钧 2019-02-17T15:50:46Z https://communities.sas.com/t5/New-SAS-User/Difference-between-NODUPKEY-and-NODUPRECS/m-p/536271#M6614 NODUPRECS has been removed from PROC SORT (documentation) but it still works for backwards compatibility. I would not recommend developing any programs that rely on the functionality of NODUPRECS today. <BR /><BR />If you've read the paper, there are some gotcha's about it that often caught people, so they changed the functionality. Sun, 17 Feb 2019 19:19:38 GMT https://communities.sas.com/t5/New-SAS-User/Difference-between-NODUPKEY-and-NODUPRECS/m-p/536271#M6614 Reeza 2019-02-17T19:19:38Z https://communities.sas.com/t5/New-SAS-User/Difference-between-NODUPKEY-and-NODUPRECS/m-p/541755#M7418 <P style="margin: 1pt 0in;"><FONT color="#000000" face="Arial">In addition to Reeza, another person from SAS Support also said that NODUPRECS has been removed from the most recent documentation (9.4) because it works in an unexpected/unreliable way.</FONT></P> <P style="margin: 1pt 0in;"><FONT color="#000000" face="Arial">Instead of NODUPRECS, the current suggestion is to use NODUPKEY and to sort BY _ALL_</FONT></P> Sun, 10 Mar 2019 00:09:55 GMT https://communities.sas.com/t5/New-SAS-User/Difference-between-NODUPKEY-and-NODUPRECS/m-p/541755#M7418 agoldma 2019-03-10T00:09:55Z