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iamsunix wrote:

> In delphi7, I see some codes in system.pas
> 
>  //varDecimal  = $000E; { vt_decimal     14 } {UNSUPPORTED as of v6.x
> code base}
> 
> It seem that delphi7 does not support decimal type of variant.
> 
> :(
> 
> Now, I use ADOInt._Recordset to open a recordset from MS SQLServer, my
> recordset(var RS: _Recordset) include one field(FieldName is
> 'Amount') which fieldType is adDecimal(declare in adoint.pas), but it
> is not supported by delphi7. the follwing codes will raise exception:
> 
>    if RS.Field['Amount'].Value > 0 then  //raise exception
>    begin
>      ...
>    end;
> 
> How can I do? How can I make delphi7 support vardecimal? why delphi7
> remove vardecimal type of Variant?

It did not remove it, you misinterpret the comment. It was never
supported by Delphi, D5 did not even define a constant for it.
DECIMAL is not an automation-compatible data type, MS added it
specifically for SQL Server support via ADO.

It is possible to work with unsupported variant types in Delphi, but it
is cumbersome. The first thing you have to do is test the actual data
type of the variant.

 uses ActiveX;  // this unit declares the API functions for variant
manipulation

 var
   V: OleVariant;
  Value: Double;
 
  ...
  V:= RS.Field['Amount'];
  if VarType(V) = varDecimal then begin
    OleCheck(VarR8FromDec(TVarData(V).varAny, Value));
    if value > 0 then
      ....    
  end;
    
 This technique becomes particularly painful when the automatic variant
cleanup Delphi does on V above blows up as well. In such a case you
have to call
  
 VariantClear(V);

explicitely. 



-- 
Peter Below (TeamB)  
Don't be a vampire (http://slash7.com/pages/vampires), 
use the newsgroup archives :
http://www.tamaracka.com/search.htm
http://groups.google.com
http://www.prolix.be

Thank you very much:)

"Peter Below (TeamB)" <none> 
??????:xn0f1d5746ifs300a@newsgroups.borland.com...
> iamsunix wrote:
>
>> In delphi7, I see some codes in system.pas
>>
>>  //varDecimal  = $000E; { vt_decimal     14 } {UNSUPPORTED as of v6.x
>> code base}
>>
>> It seem that delphi7 does not support decimal type of variant.
>>
>> :(
>>
>> Now, I use ADOInt._Recordset to open a recordset from MS SQLServer, my
>> recordset(var RS: _Recordset) include one field(FieldName is
>> 'Amount') which fieldType is adDecimal(declare in adoint.pas), but it
>> is not supported by delphi7. the follwing codes will raise exception:
>>
>>    if RS.Field['Amount'].Value > 0 then  //raise exception
>>    begin
>>      ...
>>    end;
>>
>> How can I do? How can I make delphi7 support vardecimal? why delphi7
>> remove vardecimal type of Variant?
>
> It did not remove it, you misinterpret the comment. It was never
> supported by Delphi, D5 did not even define a constant for it.
> DECIMAL is not an automation-compatible data type, MS added it
> specifically for SQL Server support via ADO.
>
> It is possible to work with unsupported variant types in Delphi, but it
> is cumbersome. The first thing you have to do is test the actual data
> type of the variant.
>
> uses ActiveX;  // this unit declares the API functions for variant
> manipulation
>
> var
>   V: OleVariant;
>  Value: Double;
>
>  ...
>  V:= RS.Field['Amount'];
>  if VarType(V) = varDecimal then begin
>    OleCheck(VarR8FromDec(TVarData(V).varAny, Value));
>    if value > 0 then
>      ....
>  end;
>
> This technique becomes particularly painful when the automatic variant
> cleanup Delphi does on V above blows up as well. In such a case you
> have to call
>
> VariantClear(V);
>
> explicitely.
>
>
>
> -- 
> Peter Below (TeamB)
> Don't be a vampire (http://slash7.com/pages/vampires),
> use the newsgroup archives :
> http://www.tamaracka.com/search.htm
> http://groups.google.com
> http://www.prolix.be
>