Used with BEGIN_COLUMN_MAP and END_COLUMN_MAP to bind a binary large object (BLOB). Similar to BLOB_ENTRY, except that this macro takes a column name instead of a column number.
BLOB_NAME(pszName, IID, flags, data )
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".
[in] Interface GUID, such as IDD_ISequentialStream, used to retrieve the BLOB.
[in] Storage-mode flags as defined by the OLE Structured Storage model (for example, STGM_READ).
[in] The corresponding data member in the user record.
See How Can I Retrieve a BLOB?.