Q190624: PRB: SYS(2018) May Return More Than the Message Parameter

Article: Q190624
Product(s): Microsoft FoxPro
Version(s): WINDOWS:5.0,5.0a,6.0
Operating System(s): 
Keyword(s): 
Last Modified: 11-DEC-1999

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 5.0, 5.0a, 6.0 
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SYMPTOMS
========

When a table is created programmatically, the Check clause can be used to
perform field level validations. When a field level error occurs, either the
SYS(2018) or the AERRORS function can be used to display the source of the
error. In Visual FoxPro 3.0, the error message parameter that was involved in
the generated error was returned. This behavior is different in Visual FoxPro
5.0 and 6.0. In the latter versions of Visual FoxPro, the entire error message
is returned by default.

RESOLUTION
==========

To work around this behavior use the Error cause in the CREATE TABLE, Check
statement, as shown in the MORE INFORMATION section.

STATUS
======

This behavior is by design.

MORE INFORMATION
================

Steps to Reproduce Behavior
---------------------------

1. Run the following code to see the behavior. When the code executes, the
  program continues when an error occurs and the error is displayed using
  SYS(2018) and the AERRORs array. Run the code and first do not select the
  work around and you will see the default error message parameter. If you want
  to see the work around, the CREATE TABLE with the ERROR clause is used.

  Sample Code
  -----------

        *-- Code begins here.
        CLEAR
        ON ERROR *
        IF ADIR(myTestFiles, "sys2018*.dbc") > 0
            nErase=MESSAGEBOX("Erase SYS(2018) Files?",4)
        ENDIF
        IF nErase = 6
            CLOSE DATA
            ERASE sys2018.*
            CREATE DATA sys2018
            OPEN DATA sys2018
            nError = MESSAGEBOX("Workaround?",4)
            IF nError = 6
                CREATE TABLE sys2018 (NAME c(10) CHECK NAME="Moe" ;
                ERROR "NAME")
            ELSE
                CREATE TABLE sys2018 (NAME c(10) CHECK NAME="Moe")
            ENDIF
        ENDIF

        INSERT INTO sys2018 VALUES ("NotMoe")

        &&This causes a validation error.
        ?"SYS(2018) = " + SYS(2018)
        ?
        ?
        =AERROR(aTest)
        DISPLAY MEMO LIKE aTest
        CLOSE DATA ALL
        ON ERROR
     *-- Code ends here.

After the preceding program is finished, the files created can be deleted by
issuing the following command:

     ERASE SYS2018.*

REFERENCES
==========

Visual FoxPro Help; search on: "SYS(2018)" (without the quotation marks);
"AERROR" (without the quotation marks)

Additional query words: kbADO150 kbADO200 kbCtrl kbDatabase kbDataBinding kbvfp600 kbActiveX

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Keywords          :  
Technology        : kbVFPsearch kbAudDeveloper kbVFP500 kbVFP600 kbVFP500a
Version           : WINDOWS:5.0,5.0a,6.0
Issue type        : kbprb

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