FIX: Default Value Not Evaluated Properly Using Stored Procs (140861)


The information in this article applies to:

  • Microsoft Visual FoxPro for Windows 3.0
This article was previously published under Q140861

SYMPTOMS

Under specific circumstances where two columns are calculating default values, a stored procedure may not be executed rapidly enough resulting in default values being inserted into a table's fields instead of the data generated by the stored procedure.

CAUSE

If the stored procedure that calculates the default value takes too long, a default of 0 is used for numeric fields. This is a result of a timing issue, and not a coding issue.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. This problem was corrected in Visual FoxPro 3.0b for Windows.

MORE INFORMATION

The following code, when run using Visual FoxPro 3.0, demonstrates the behavior noted in this article. After a few records, the program will fail with one of several error messages. Using Visual FoxPro 3.0b, this code runs successfully.

Steps to Reproduce Problem

  1. Place the following two functions into a program file called Bug.sp: 
       FUNCTION spIncr
      PARAMETER cAliasName, cFname
      PRIVATE iNewVal
      lOldDel = SET ("DELETED")
      SET DELETED OFF
      SELECT MAX(&cFname) FROM (cAliasName) INTO ARRAY tmparr
      SET DELETED &lOldDel
      IF (_TALLY = 0)
        RETURN 1
      ENDIF
      iNewVal = tmparr(1) + 1
      RETURN iNewVal
   ENDFUNC

   FUNCTION spDefVal
      PARAMETER cAliasName, cFname, aDefRetVal
      PRIVATE aNewVal
      aNewVal = .NULL.
      ON Error *
      aNewVal = aDefRetVal
      aNewVal = &cAliasName..&cFname
      ON Error
      RETURN aNewVal
   ENDFUNC
  2. Execute the following code from a second .prg file: 
       SET SAFETY OFF
   CLOSE DATABASE ALL
   CREATE DATABASE 'bugreport.DBC'
   APPEND PROCEDURES FROM 'bug.sp'
   COMPILE DATABASE bugreport.DBC
   CREATE TABLE 'bug' (NR1 I NOT NULL Default spIncr("bug","nr1"), ;
                      NR2 I NOT NULL Default spDefVal("anytable", ;
                      "anyfield",0))
   ALTER TABLE 'bug' ADD PRIMARY KEY NR1 Tag NR1
   INDEX ON NR2 Tag NR2

   USE bug
   BROWSE NOWAIT
   FOR idat = 1 TO 200
      KEYBOARD "{CTRL+Y}" && Append blank
   NEXT
Modification Type:MajorLast Reviewed:3/24/2000
Keywords:kbbug KB140861 kbAudDeveloper
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