Help using GetColumnInfo()...

Hi, I'm trying to use the following piece of code to obtain the column names from the table in SQL Server, but somehow I'm getting the wrong number of columns in ul_numColumns (see code), and only the first column name in pstr_stringBuffer. Presumably I should be getting a whole string with all the column names there, but I don't. Any suggestions for what I may be doing wrong?..

Thanks in advance

int GetColumnNames(void)

{

try

{

pCommand.CreateInstance(__uuidof (Command));

pCommand->ActiveConnection = pConn;

pCommand->CommandText = "SELECT * FROM t25_pallet_status"; // SQL Syntax...

pRecordset.CreateInstance (__uuidof (Recordset));

pRecordset->CursorLocation = adUseClient;

pRecordset->Open( (IDispatch *) pCommand, vtMissing, adOpenStatic,

adLockReadOnly, adCmdUnknown);

// Get ADORecordsetConstruction interface from the the ADO Recordset

ADORecordsetConstruction *p_adoRecordsetConstruct;

pRecordset->QueryInterface(__uuidof(ADORecordsetConstruction),

(void **)&p_adoRecordsetConstruct);

// From it, we can get the OLEDB <code>IRowset

IRowset *p_rowset;

p_adoRecordsetConstruct->get_Rowset((IUnknown **)&p_rowset);

p_adoRecordsetConstruct->Release(); // don't need it anymore

// The IColumnsInfo that contains ordinals

CComPtr<IColumnsInfo> spColumns;

// Get the the IColumnsInfo from IRowset interface

p_rowset->QueryInterface(&spColumns);

// At this point, we may now release p_rowset

p_rowset->Release();

// IColumnsInfo will give us the DBCOLUMNINFO structure

ULONG ul_numColumns;

DBCOLUMNINFO *p_columnInfo = NULL;

OLECHAR *pstr_stringBuffer = NULL;

// Now get the DBCOLUMNINFO data

spColumns->GetColumnInfo(&ul_numColumns, &p_columnInfo, &pstr_stringBuffer);

// Clean up

CoTaskMemFree(p_columnInfo);

CoTaskMemFree(pstr_stringBuffer);

}

catch(_com_error & ce)

{

PrintComError(ce);

return 0;

}

}

You can do the following to get all the column names

for(ULONG j=0; j<ul_numColumns; j++)

printf("%S\t", p_columnInfo[j].pwszName);

Hope this helps

|||

Thanks a lot Raj,

I kind of sussed it out for my self a short while after I posted the message. I didn't really understand how GetColumnInfo() worked, and I was expecting pstr_stringBuffer to return a string with ALL of the column names (separated by a common delimitter or something). It became apparent to me that I had to loop through and read from a different variable (pwszName) in order to get those names.

I have to say there's very little on examples out there to use functions like this one. Can anyone recomend me a good website where I can get sample code from in C or C++ for the Visual Studio 2003 environment?

Cheers