Returning CDBVariant type

[mesajflaviu]

I have the following method to format data type returned from SQL:

CString CMyDoc::FormatData(CDBVariant* pDBVariant)
{
	CString sRet;
*
	switch(pDBVariant->m_dwType)
	{
	case DBVT_LONG:
		TRACE("DBVT_LONG\n");
		sRet.Format(_T("%d"), pDBVariant->m_lVal);
		break;
	case DBVT_DOUBLE:
		TRACE("DBVT_DOUBLE\n");
		break;
	case DBVT_SHORT:
		TRACE("DBVT_SHORT\n");
		break;
	case DBVT_SINGLE:
		TRACE("DBVT_SINGLE\n");
		break;
	case DBVT_STRING:
		TRACE("DBVT_STRING\n");
		break;
	case DBVT_ASTRING:
		TRACE("DBVT_ASTRING\n");
		sRet = *pDBVariant->m_pstring;
		break;
	case DBVT_DATE:
		TRACE("DBVT_DATE\n");
		break;
	case DBVT_WSTRING:
		TRACE("DBVT_WSTRING\n");
		CStringW wstring = *pDBVariant->m_pstringW;
		sRet = CString(wstring);
		break;
	}
*
	return sRet;
}

I have the following SQL:

SELECT nUser FROM my_table

In DB, nUser has "int" type. The result in FormatData method: DBVT_LONG

I have another SQL:

SELECT sName FROM my_table

In DB, dValue has "varchar(1024)" type. The result in FormatData method: DBVT_ASTRING - correct.

I have another SQL:

SELECT dValue FROM my_table

In DB, dValue has "decimal (10.2)" type. The result in FormatData method: DBVT_ASTRING !? Why ?

I noticed that any king of column type in DB, except "int" type, return DBVT_ASTRING in FormatData method ... why ?

I have tried to get data with CRecordset as dynaset, snaphot and dynamic ... every one of them had the same result ...

Can you help me ?
Thank you.

[VictorN]

...
I have another SQL:

SELECT dValue FROM my_table

In DB, dValue has "decimal (10.2)" type. The result in FormatData method: DBVT_ASTRING !? Why ?

I noticed that any king of column type in DB, except "int" type, return DBVT_ASTRING in FormatData method ... why ?

I have tried to get data with CRecordset as dynaset, snaphot and dynamic ... every one of them had the same result ...

Maybe because CDBVariant class has no such a type as "decimal"?

[VictorN]

See also the table with C/SQL data type compatibility here.

[mesajflaviu]

Hi Victor. I saw from the above table, that setting up SQL_DECIMAL in my database, is returning SQL_C_CHAR in CDBVariant ... so, helped by you, I have found the source of the problem ... however, I don't know if I can change this decimal type in DB, I will see this after I talk with my SQL colleagues ...

Kindly thank you for your answers !

[VictorN]

... however, I don't know if I can change this decimal type in DB, ...

But why do you think you have to "change this decimal type in DB"?
You do not need it!

[mesajflaviu]

No ? This is mean I don't understand the solution ...

So, if the SQL data type are decimal SQL_DECIMAL, I retrieve SQL_C_CHAR in my CDBVariant ... I am right ?

[VictorN]

So, if the SL data type are decimal SQL_DECIMAL, I retrieve SQL_C_CHAR in my CDBVariant ... I am right ?

Yes!