Understood, but one finalizing question: A B C 1 1 1 1 1 1 -0- 2 2 -0- 2 2 Still: EQNULL: OFF DELETE DUPLICATES FROM TAB USING A, B, C Result: first 2 rows are removed, row 3 and 4 not. Problem: the .. USING extension does not solve the problem in big tables either Consequence: incl. the settings before the command for now ... SET EQNULL ON DELETE DUPLICATES FROM tab --DELETE DUPLICATES FROM tab USING A,B, C SET EQNULL OFF
with very best regards Fritz -----Ursprüngliche Nachricht----- Von: [email protected] [mailto:[email protected]] Im Auftrag von A. Razzak Memon Gesendet: Sonntag, 8. Dezember 2013 00:43 An: RBASE-L Mailing List Betreff: [RBASE-L] - Re: DELETE DUPLICATES, Setting: SET EQNULL OFF At 06:18 PM 12/7/2013, Dr. Fritz Luettgens wrote: >In my table not all colums have values, but duplicates exist. >My standard setting is: SET EQNULL OFF, NULL: -0- I want: DELETE >DUPLICATES FROM TABLE result is: 0 duplicates have been deleted but >when: SET EQNULL ON the command is successful: n duplicates have been >deleted ! >Question: Should this command not also work on a table with setting SET >EQNULL OFF ? Dr. Fritz, Here's a technical explanation ... When using the DELETE DUPLICATES command without specifying the "USING columnname", all matching rows and columns, including the columns with NULL values are evaluated. The EQNULL setting as TRUE (ON) means that a comparison between two NULL values is a match and that a comparison between a NULL value and a non-NULL value is not. When EQNULL is set to FALSE (OFF) then a comparison between two NULL values is not a match nor is a comparison between a NULL value and a non-NULL value a mismatch. The NULL value essentially make the whole thing "unknown'. Hope that helps you understand the difference. If you need a few examples to understand this whole thing practically, feel free to reach out to me with further questions. Very Best R:egards, Razzak. www.rbase.com www.facebook.com/rbase -- 30+ years of continuous innovation! 15 Years of R:BASE Technologies, Inc. making R:BASE what it is today! -- --- RBASE-L =======================3D=======================3 D= TO POST A MESSAGE TO ALL MEMBERS: Send a plain text email to [email protected] (Don't use any of these words as your Subject: INTRO, SUBSCRIBE, UNSUBSCRIBE, SEARCH, REMOVE, SUSPEND, RESUME, DIGEST, RESEND, HELP) =======================3D=======================3 D= TO SEE MESSAGE POSTING GUIDELINES: Send a plain text email to [email protected] In the message SUBJECT, put just one word: INTRO =======================3D=======================3 D= TO UNSUBSCRIBE: Send a plain text email to [email protected] In the message SUBJECT, put just one word: UNSUBSCRIBE =======================3D=======================3 D= TO SEARCH ARCHIVES: Send a plain text email to [email protected] In the message SUBJECT, put just one word: SEARCH-n (where n is the number of days). In the message body, place any text to search for. =======================3D=======================3 D=
