Thanks Razzak and James. I think I understand the purpose and use of the SET ERROR Var and the "holding" variables you suggested Razzak.
Also if I understand correctly, I can turn off the Error message for the specific error without affecting the actual error itself. I am just turning it off so the message does not pop up in the middle of a command. By employing both the SET ERROR MESSAGE 2059 OFF and the SET ERROR VAR command with the holding variables (and the IF THEN statement) I can bypass the error and complete the remainder of the code, then turn off the ERROR VAR. I will be testing this on Monday. Thanks again. Jim -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of A. Razzak Memon Sent: Saturday, March 06, 2010 11:02 AM To: RBASE-L Mailing List Subject: [RBASE-L] - Re: error variable At 10:40 AM 3/6/2010, Jim Belisle wrote: >I have never used the SET ERROR VAR code before and would like to >verify I understand the explanation in the Help. Jim, A well written R:BASE program need to be able to check and determine if key lines are executed or the proper answers are given -- and, if not, then display an error message or run alternative commands. R:BASE has three different ways to check the code for proper execution. The three ways you can process R:BASE errors in your application code are: the R:BASE ERROR VARIABLE, SQLCODE, and the WHENEVER statement. R:BASE ERROR VARIABLE The first, and most commonly used, is the ERROR VARIABLE. The ERROR VARIABLE is a special variable defined to hold the error codes that R:BASE returns. The first step in using the error variable is to define the name of the variable. Use the command: SET ERROR VARIABLE ErrorVar, where ErrorVar is the name of the variable that contains the error code. You can name the error variable any name you want. The error variable has a value after every command in a program or R:BASE session. The value is either 0 (successful command) or a number indicating the error that occurred on the last executed command. Because the R:BASE error variable is set after every command, when checking the errorcode the very next line after the command to be checked must test the error variable or place its value into a holding variable: SET VARIABLE vhold =.errorvar. The variable vhold is then used to determine what happens next in the program. There is only one error variable in a program (errorvar), but there can be many holding variables (vhold). Holding variables are needed because the error variable is set after every command. For example, PAUSE is a command that always executes successfully, so the error variable is always set to 0 after it. To turn off an error variable or to use one with a different name you must use the SET ERROR VARIABLE OFF command. When using an error variable do not clear it with the CLEAR VAR command. When clearing variables always use the CLEAR ALL VAR EXCEPT errorvar. You can generate other errors in your application by clearing an error variable instead of setting it off. Error codes trapped by the error variable are not only for SQL commands, but any command that can be used in R:BASE. This is different from the other techniques as they only check the commands that are SQL specific. A useful technique in identifying errors in the code is to place an IF statement based on the holding variable to redirect the flow of the code and to provide a message to the user. For example: SET ERROR VARIABLE vError CONNECT RRBYW16 IDENTIFIED BY NONE -- SHOW ERROR vError command will display the R:BASE message SET VAR vHold = .vError IF vHold <> 0 THEN CLS PAUSE 2 USING 'Error Connecting Database.' + CAPTION ' Running R:BASE Your Way!' + ICON STOP + BUTTON 'Press any key to continue ...' + OPTION MESSAGE_FONT_COLOR RED + |MESSAGE_FONT_NAME VERDANA + |MESSAGE_FONT_SIZE 11 + |MESSAGE_FONT_BOLD OFF + |BUTTON_COLOR WHITE + |BUTTON_FONT_COLOR GREEN + |THEMENAME Vista CG RETURN ENDIF Important Notes: . Any successful command will always set the value to 0. . Use SET ERROR VARIABLE OFF to turn off the process. . Only one error variable is used in an R:BASE session. An R:BASE session is from when you start R:BASE until you EXIT. Hope that helps! Very Best R:egards, Razzak.
