ASCII 20 is "SPACE", 160 is "NON-BREAKING SPACE". 160 is for software to distinguish when the character following should not be separated from the character or word preceding the 160.
----- Original Message ----- From: "Stephen Markson" <[email protected]> To: "RBASE-L Mailing List" <[email protected]> Sent: Monday, April 23, 2012 9:48 AM Subject: [RBASE-L] - Re: null : Be careful Bruce, : : CHAR(255) worked as a hard space in DOS (ASCII character set), but with the usual Windows ANSI character set it’s CHAR(160). : : If you type [Alt]255 at the R>, CHAR(160) is generated. To type CHAR(x), press [Alt]0x, for example, [Alt]0255. In Windows, CHAR(255) is “y” with an umlaut (ÿ). : : Try this: At the R>, type: : : SET VAR X TEXT=' : : Then, press [Alt]255, the single quote and [Enter]. : : Now enter this command: : : SET VAR N=(ICHAR(.X)) : : The value of N should be 160. : : : Regards, : : Stephen Markson : The Pharmacy Examining Board of Canada : 416.979.2431 x251 : : From: [email protected] [mailto:[email protected]] On Behalf Of Bruce Chitiea : Sent: Sunday, April 22, 2012 8:20 PM : To: RBASE-L Mailing List : Subject: [RBASE-L] - Re: null : : Mike(s): : : I haven't experimented with R:Base yet, but I've used [Alt-255] for years to force 'hard' spaces where 'soft' spaces get stripped or ignored. : : Bruce : : : -------- Original Message -------- : Subject: [RBASE-L] - Re: null : From: "Mike Byerley" <[email protected]<mailto:[email protected]>> : Date: Sun, April 22, 2012 12:41 pm : To: [email protected]<mailto:[email protected]> (RBASE-L Mailing List) : : I wish RBase would treat [Space] with the respect it deserves.. ;-) : : Really, if you wish a string to have a trailing space, it should have one. : The Trim functions (Trim, LTrim, RTrim) are purpose bent for the user to use : them as appropriate. : : : : ----- Original Message ----- : From: "Bruce Chitiea" <[email protected]<mailto:[email protected]>> : To: "RBASE-L Mailing List" <[email protected]<mailto:[email protected]>> : Sent: Sunday, April 22, 2012 2:13 PM : Subject: [RBASE-L] - Re: null : : : Mike: : : Mike Byerley's got your answers. : : But more conceptually, nulls, blanks and spaces are apples, oranges and : bananas. : : 'Null' literally means 'no value', which might have several meanings: : : a) There may be a value for this field out there, but we just don't know : it (and may never know); : b) There may be NO value for this field out there, but we don't know : that either; : c) There's NO value which makes sense in this field (in this : particularly usage of the data). : : The formal relational model calls for the introduction of a special, : reserved marker to represent fields which contain 'no value'. In R:Base, : this is the string '-0-'. R:Base allows the user to introduce a : character or string to represent nulls; a freedom with risk. : : The introduction of the semantic term 'blank' is what's tripping you up. : : We think of 'blank' as meaning 'no value'; and a 'space' as a : representation of 'blank'. In a word processing context, this is right : and proper. But a 'space' is an actual value: ASCII 32; so within a a : database context, using a 'space' to represent 'blank' to represent : 'null' introduces a value where there should be none; thus defeating the : very purpose of 'null'. : : To represent nulls in reports (using the R:Base report designer), you : can change the printed representation of nulls to the 'space' without : doing violence to null protection: : : From R:Base help: : : 1. [Right-click] on the column object whose nulls you wish to represent; : 2. From the drop-down menu, select 'NULL Format:' : 3. Enter the string (which just might be an ASCII 32 space) you wish to : print in the place of '-0-' : : A disquieting snippet from R:Base help: : : "If you set null to a blank space, R:BASE does not display rows : composed entirely of nulls with the SELECT command." : : I take that to mean that a select would return rows with NULLs and : spaces, which might have a meaning totally out of sync with what you : intend. : : Hope this helps, and Cheers, : : Bruce : : -------- Original Message -------- : Subject: [RBASE-L] - Re: null : From: "Mike Byerley" <[email protected]<mailto:[email protected]>> : Date: Sat, April 21, 2012 1:47 pm : To: [email protected]<mailto:[email protected]> (RBASE-L Mailing List) : : Mike, : Try this and see what the results are before you set null to ' ' : If you are expecting null to be a space, you will be disappointed. : : SET VAR vemptyspace TEXT = '' : SET VAR vspace TEXT = ' ' : SET VAR vblank TEXT = (CHAR(32)) : : SET VAR vtest TEXT = ('RBASE' + .vemptyspace + 'ROCKS') : PAUSE 2 USING .vtest : SET VAR vtest TEXT = ('RBASE' + .vspace + 'ROCKS') : PAUSE 2 USING .vtest : : SET VAR vtest TEXT = ('RBASE' + .vblank + 'ROCKS') : PAUSE 2 USING .vtest : : RETURN : : If you want null to be just invisible for display purposes (devoid of : the -0- in fields that are nulls) then set the null character to an : unprintable ascii value like Char(160) : : It has been recommended practice for as long as I can remember to set : null : to -0- before unloading data. : : you can set null to that value by the recommended method of: : : set null '-0-' : : At the start of an RBase session, I include this: : : set null '-0-' : set var vHoldNull = (CVAL('NULL')) : : then at the conclusion of the session: : : set null .vHoldNull : : Then if the session ends back in RBase RDBMS interface, my null setting : is : back to the recommended setting for unload. I don't change the null : setting : to do ReLoad FWIW. : : In your examples, you had null set to Two blanks and Three blanks, but : it : doesn't matter, since RBase strips out blanks in an expression as my : example : shows. : : : ----- Original Message ----- : From: "mike epstein sony viao office" <[email protected]<mailto:[email protected]>> : To: "RBASE-L Mailing List" <[email protected]<mailto:[email protected]>> : Sent: Saturday, April 21, 2012 3:28 PM : Subject: [RBASE-L] - null : : :: Can anyone clarify the meaning, and usage of :: :: :: :: :: :: Set null ' ' :: :: :: :: Set null -0- :: :: :: :: Set var <varname> <vartype> = null :: :: :: :: Does the Set var <varname> <vartype> = null make a variable that has a :: value, change it to ' ' (blank) :: :: :: :: :: :: On a network with 2 workstations Is the setting on the local computers : cfg :: file affected by changes in an eep , say that sets null to -0- inserts : : or :: updates into a table and then before exiting the eep sets null = ' '. :: :: :: :: :: :: Should the -0- only be used to unload data and structure from a table? :: :: Should the -0- only be used to reload or pack the database ? :: :: :: :: I have set null in the configuration setting to blank from -0- , when : I :: close the configuration settings I get an error message that says ' : cannot :: save c:\windows\rbengine91_64.cfg. It does not matter if I change the : order :: ie -0- to blank :: :: Either way whatever symbol is input into the null configuration : setting : is :: the setting in the application :: :: :: :: I am also experiencing that the -0- all of the sudden appears when the :: application is run while tracing with no change in the ' ' setting by : the :: program :: :: :: :: :: :: :: :: :: :: : : --- RBASE-L ================================================ 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) ================================================ TO SEE MESSAGE POSTING GUIDELINES: Send a plain text email to [email protected] In the message SUBJECT, put just one word: INTRO ================================================ TO UNSUBSCRIBE: Send a plain text email to [email protected] In the message SUBJECT, put just one word: UNSUBSCRIBE ================================================ 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). 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