OLEDB interface reads the conversion method of each data type (code 8)

DBSTATUS DBSTATUS;

DBTYPE DBTYPE;

CString Str;

Double Dvalue; Long Lvalue;

// Paccessor is a pointer to the CDynamicAccessor object

// ncol is the list of read columns

Paccessor-> GetStatus (ncol, & dbstatus);

IF (DBSTATUS! = dbstatus_s_isnull && paccessor-> getColumnType (ncol, & dbtype))

{

Switch (DBTYPE)

{

Case DBTYPE_VARIANT:

Vt = Colevariant (LPCVARIANT) Paccessor-> getValue (ncol));

Break;

Case DBTYPE_STR:

Str = (lpcstr) Paccessor-> getValue (ncol);

Break;

Case DBTYPE_WSTR:

Case DBTYPE_BSTR:

Str = (lpcwstr) Paccessor-> getValue (ncol);

Break;

Case DBTYPE_I1:

Case DBTYPE_UI1:

Lvalue = (long) (* (Byte *) Paccessor-> getValue (ncol)));

Break;

Case DBTYPE_I2:

Case DBTYPE_UI2:

Lvalue = (long) (* (short *) paccessor-> getValue (ncol)));

Break;

Case DBTYPE_I4:

Case DBTYPE_UI4:

Lvalue = (long) (* ((long *) paccessor-> getValue (ncol)));

Break;

Case DBTYPE_R4:

DVALUE = (Double) (* (Float *) Paccessor-> getValue (ncol)));

Break;

Case DBTYPE_R8:

DVALUE = * ((Double *) Paccessor-> getValue (ncol));

Break;

Case DBTYPE_NUMERIC:

{

DB_NUMERIC NUM;

IF (Paccessor-> GetValue (Ncol, & Num))

{

DVALUE = (Double) * ((__ tent64 *) Num.val);

While (Num.scale -> 0)

DVALUE / = 10;

IF (Num.Sign == 0)

DVALUE = -dvalue;

}

}

Break;

Case dbtype_varnumeric:

{

// MSDN has this part of the code, but there is a mistake, here is made

DVALUE = 0;

Unsigned long ncolumn = ncol;

DB_VARNUMERIC * PNUM;

Paccessor-> TranslateColumnno (NCOLUMN);

PNUM = (DB_VARNUMERIC *) Paccessor -> _ getDataPtr (ncolumn);

Ulong ulength = 0;

Paccessor-> getLength (Ncol, & ULENGTH);

INT PREC = (int) pNum-> precision;

INT scale = (int) pnum-> scale;

INT SIGN = (int) (pnum-> sigh> 0)? 1: -1; Byte Hi, LO;

Double Multiplier = 1;

Double Adjust = 1;

ULENGTH - = (SizeOf (dbtype_varnumeric) - 1);

For (ulong i = 0, j = 0; i

{

Hi = LO = PNUM-> VAL [i];

LO << = 4;

Lo >> = 4;

DVALUE = ((Ulong) LO) * MultiPlier;

MultiPlier * = 16;

Hi >> = 4;

DVALUE = ((Ulong) Hi) * Multiplier;

MultiPlier * = 16;

}

Adjust * = POW (10, scale) * Sign;

DVALUE / = adjust;

}

Break;

Case DBTYPE_DBDATE:

{

DBDATE DBDATE;

IF (Paccessor-> getValue (ncol, & dbdate))

{

CTIMETM (dbdate.year, dbdate.month, dbdate.day, 0, 0, 0);

}

}

Break;

Case DBTYPE_DBTIMESTAMP:

{

DBTimeStamp DBTimeStamp;

IF (Paccessor-> getValue (ncol, & dbtimestamp))

{

CTIMETM (dbtimestamp.year, dbtimestamp.month, dbtimestamp.day,

DBTimeStamp. Hour, dbtimestamp.minute, dbtimestamp.second;

Lvalue = tm.gettime ();

}

}

Break;

Case DBTYPE_DATE:

{

COLEDATETIME DT (* ((DATE *) Paccessor-> getValue (ncol)));

Lvalue = dt.getyear () * 10000 dt.getmonth () * 10000 dt.getday ();

}

Break;

Case DBTYPE_DBTIME:

{

DBTime dbtime;

IF (Paccessor-> GetValue (ncol, & dbtime))

{

Dt.SetTime (dbtime. Hour, dbtime.minute, dbtime.second);

Vt = Colevariant (DT);

}

}

Break;

Case DBTYPE_CY:

{

Colecurrency Cy (* ((currentcy *) Paccessor-> getValue (ncol)))))

Vt = Colevariant (CY);

}

Break;

Case DBTYPE_IUNKNOWN:

{

ISEQUENTIALSTREAM * PSTREAM = * (ISEQUENTIALSTREAM **) Paccessor-> getValue (ncol);

IF (PStream! = null)

{

CString Str;

Unsigned long Lread = 0;

Unsigned long loadthis = 0;

CbyteArray aybytes;

Byte Szbuffer [4096]; BYTE * PBYTE = NULL;

DO

{

PStream-> Read (Szbuffer, 4096, & Lreadthis);

IF (LreadThis> 0)

{

Aybytes.setsize (Lread LreadThis);

PBYTE = aybetes.getdata ();

Memcpy (Pbyte Lread, Szbuffer, LreadThis);

Lread = Lreadthi;

}

} while (Lreadthis == 4096);

Aybytes.setsize (LREAD);

Vt = aybytes;

}

}

Break;

Case DBTYPE_NULL:

Case DBTYPE_EMPTY:

DEFAULT:

Break;

}

}