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[BUG/PRB.] VFP 9.0 FIX - CONVERTE ALL CHARACTERS WHEN CONVERTING CHARACTER FIELDS TO NUMERIC FIELDS
January 2025
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CCB
1. BUG:
In vfp9, for some update table commands,
it will convert up to 18 characters when converting Character or Varchar fields to Numeric, Float, Double or Integer fields.
The bug only occurs in vfp 9.0.0.3504 (SP1) or later, it does not occur in vfp6, vfp7, vfp8 and vfp 9.0.0.2412.
The bug occurs in the following update table commands:
ALTER TABLE - SQL command
APPEND command
GATHER command
MODIFY STRUCTURE command
UPDATE - SQL command
There is a test program:
*PROC testaltertable
CLOSE DATABASES ALL
CLOSE TABLES ALL
SELECT 0
CREATE TABLE ("testaltertable.dbf") (fld1 c(30))
USE
SELECT 0
USE ("testaltertable.dbf") ALIAS testaltertable EXCLUSIVE
APPE BLANK
REPL fld1 WITH SPACE(15)+"123456.78"
?fld1
WAIT
ALTER TABLE ("testaltertable.dbf") ALTER fld1 N(20,2)
?fld1 && Displays 123.00, the data has been lost.
WAIT
USE
RETURN
* END OF PROC TESTALTERTABLE.
2. CAUSE:
In VFP 9.0.0.3504 (SP1) or later, it will convert up to 18 characters when converting Character or Varchar fields
to Numeric, Float, Double or Integer fields, for example,
fld1 = SPACE(15)+"123456.78"
it will convert SPACE(15)+"123" to a Numeric field,
so fld1 = 123.00
In VFP Advanced, it will convert all characters (up to 255 characters) when converting Character or Varchar fields
to Numeric, Float, Double or Integer fields, for example,
fld1 = SPACE(15)+"123456.78"
it will convert SPACE(15)+"123456.78" to a Numeric field,
so fld1 = 123456.78
so there is no the bug.
There are some BUGs in the following code.
3. RESOLUTION:
We can write some code to fix the BUG.
Label597f85 ::
pushd 0FFh ;0x00597f85 : 68ff000000
mov eax , ebx ;0x00597f8a : 8bc3
call Fun75ee1b ;0x00597f8c : e88a6e1c00
mov eax , dword ptr [ ebx + 8 ] ;0x00597f91 : 8b4308
cmp eax , esi ;0x00597f94 : 3bc6
jb Label597f9a ;0x00597f96 : 7202
;
; --------------------------------------------------------------------------------------------------
; VFP 9.0 FIX - CONVERTE ALL CHARACTERS WHEN CONVERTING CHARACTER FIELDS TO NUMERIC FIELDS
; December 2024
; --------------------------------------------------------------------------------------------------
; CCB
;
; In vfp9, for some update table commands,
; it will convert up to 18 characters when converting Character or Varchar fields to Numeric, Float, Double or Integer fields.
; In VFP Advanced, for some update table commands,
; it will convert all characters (up to 255 characters) when converting Character or Varchar fields to Numeric, Float, Double or Integer fields.
;
; 2024/12/20, by ccb
;
cmp dword ptr vfpa_sys9179_data,00h
jne Label597f9a
mov eax , esi ;0x00597f98 : 8bc6
Label597f9a ::
mov dword ptr [ ebx + 8 ] , eax ;0x00597f9a : 894308
Label597f9d ::
mov eax , dword ptr [ ebx + 8 ] ;0x00597f9d : 8b4308
cmp eax , esi ;0x00597fa0 : 3bc6
mov ecx , eax ;0x00597fa2 : 8bc8
jb Label597fa8 ;0x00597fa4 : 7202
;
; --------------------------------------------------------------------------------------------------
; VFP 9.0 FIX - CONVERTE ALL CHARACTERS WHEN CONVERTING CHARACTER FIELDS TO NUMERIC FIELDS
; December 2024
; --------------------------------------------------------------------------------------------------
; CCB
;
; In vfp9, for some update table commands,
; it will convert up to 18 characters when converting Character or Varchar fields to Numeric, Float, Double or Integer fields.
; In VFP Advanced, for some update table commands,
; it will convert all characters (up to 255 characters) when converting Character or Varchar fields to Numeric, Float, Double or Integer fields.
;
; 2024/12/20, by ccb
;
cmp dword ptr vfpa_sys9179_data,00h
jne Label597fa8
mov ecx , esi ;0x00597fa6 : 8bce
Label597fa8 ::
pushd 02Eh ;0x00597fa8 : 6a2e
lea eax , dword ptr [ ebx + 44 ] ;0x00597faa : 8d432c
mov dword ptr [ ebx + 8 ] , ecx ;0x00597fad : 894b08
call Fun43cd2a ;0x00597fb0 : e8754deaff
;
; --------------------------------------------------------------------------------------------------
; VFP 9.0 FIX - CONVERTE ALL CHARACTERS WHEN CONVERTING CHARACTER FIELDS TO NUMERIC FIELDS
; December 2024
; --------------------------------------------------------------------------------------------------
; CCB
;
; In vfp9, for some update table commands,
; it will convert up to 18 characters when converting Character or Varchar fields to Numeric, Float, Double or Integer fields.
; In VFP Advanced, for some update table commands,
; it will convert all characters (up to 255 characters) when converting Character or Varchar fields to Numeric, Float, Double or Integer fields.
;
; 2024/12/20, by ccb
;
cmp dword ptr vfpa_sys9179_data,00h
je Label597fb5
cmp dword ptr [ ebx + 8 ] , 012h
jb Label597fb5
mov dword ptr [ ebx + 8 ] , 012h
Label597fb5 ::
jmp Label59812b ;0x00597fb5 : e971010000
4. APPLIES TO:
VFP 9.0.0.3504 (SP1)
VFP 9.0.0.4611 (SP2)
VFP 9.0.0.5015 (SP2)
VFP 9.0.0.5411 (SP2)
VFP 9.0.0.5721 (SP2)
VFP 9.0.0.5815 (SP2)
VFP 9.0.0.6303 (SP2)
VFP 9.0.0.6602 (SP2)
VFP 9.0.0.7423 (SP2)
The bug has been fixed in VFP Advanced.
IMPORTANT NOTE:
In VFP 9.0.0.3504 (SP1) and later, we can use the following code:
USE ("testaltertable.dbf") ALIAS testaltertable EXCLUSIVE
REPLACE ALL fld1 WITH ALLTRIM(fld1)
ALTER TABLE ("testaltertable.dbf") ALTER fld1 N(20,2)
and then there is no the bug.
5. REFERENCE WEBSITES:
1, baiyujia.com:
http://www.baiyujia.com
http://www.baiyujia.com/vfpdocuments/f_vfp9fix369.asp
6. OTHER:
For reference only, there is no guarantees.
Any questions or suggestions, please send me an email at ccb2000@163.com.
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