Conversion from VT_DECIMAL TO VT_I8 failed
hfann
I have a C++ program that creates records in a MSDE2000a database. I use a
stored procedure to create the record and it returns an identity value. The
returned value is stored in a BIGINT output parameter.
CREATE PROCEDURE dbo.AddEntry
...,
@pEntryID BIGINT = NULL OUTPUT
AS
...
In C++ code:
_ParameterPtr Parm =
pCommand->CreateParameter(L"@pEntryID",adBigInt,adParamOutput,9);
pCommand->Parameters->Append(Parm);
pCommand->Execute(0,0,adCmdStoredProc);
...
__int64 iRecID = 0;
try {
_variant_t Val = Parm->Value;
iRecID = Val;
} catch(_com_error &e) {
_bstr_t sMsg = e.Description();
return -1;
}
The program runs fine on an English version of Windows XP. On a German
version of Windows 2000, the conversion (iRec = Val;) always fails with
0x80020008 COM error. In both cases, the database is created with an English
version of MSDE2000a.
Why does a BIGINT parameter becomes a VT_DECIMAL variant? Why does the
conversion failed? Did I code something wrong? What is the workaround?
Thanks,
--
Herbert
Fann Software
http://www.fannsoftware.com
Steven Cheng[MSFT]
Welcome to MSDN newsgroup.
Regarding on the Type Converting problem met in accessing database through
ado, based on the code you provided, here are some of our suggestion:
Since this is likely a environment specific problem, currently what we can
do is simply do some further tests. for the _variant_t , it has a
"ChangeType" function which can help explicitly cast the currently value in
the _variant_t instance into our specified type. I suggest you try using
this method to explicitly cast the returned value before assign it to the
_int64(long long type). Just as:
_variant_t Val = Parm->Value;
//call ChangeType here
iRecID = Val;
Please feel free to post here if there is any other findings. Thanks,
Steven Cheng
Microsoft Online Support
Get Secure! www.microsoft.com/security
(This posting is provided "AS IS", with no warranties, and confers no
rights.)
--------------------
| Thread-Topic: Conversion from VT_DECIMAL TO VT_I8 failed
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| From: "=?Utf-8?B?aGZhbm4=?=" <hf...@nospam.nospam>
| Subject: Conversion from VT_DECIMAL TO VT_I8 failed
| Date: Sun, 31 Jul 2005 19:33:12 -0700
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hfann
I have tried
iRecID = (__int64)Val;
or
Val.ChangeType(VT_I8);
iRecID = Val;
Both failed on a fresh German Windows 2000 Pro with SP4 system.
Why does a BIGINT parameter becomes a VT_DECIMAL variant? Should it create a
VT_I8 variant in the first place?
Thanks,
--
Herbert
Fann Software
http://www.fannsoftware.com
Kevin Yu [MSFT]
Based on my research, this might be a known problem in earlier version of
MDAC. Since you're using Windows 2000 sp4, I suggest you apply MDAC 2.8
sp1. You can download it from the following link and select German in the
language selection.
http://www.microsoft.com/downloads/details.aspx?FamilyID=78cac895-efc2-4f8e-
a9e0-3a1afbd5922e&DisplayLang=en
Kevin Yu
=======
"This posting is provided "AS IS" with no warranties, and confers no
rights."
hfann
After I installed a German version MDAC 2.8 SP1, the conversion still failed
with 0x80020008 error when I debuged it in VS.NET 2003.
Thanks,
--
Herbert
Fann Software
http://www.fannsoftware.com
Kevin Yu [MSFT]
In this case, I suggest you contact Microsoft PSS for this issue, since
they might have resource to test this issue. You can get the contact
information from the following link
http://support.microsoft.com/default.aspx?scid=fh;EN-US;OfferProPhone