Everybody is good, my code is roughly as follows:

 
Void foo () 
{
Try 
{
_variant_t affected=0; 
_RecordsetPtr recordset_ptr=NULL; 
_ConnectionPtr connection_ptr=NULL; 

Recordset_ptr. CreateInstance (__uuidof (you)); 
Connection_ptr. CreateInstance (__uuidof (Connection)); 

//open the link 
Connection_ptr - & gt; Open (... ) 

//query execution 
Connection_ptr - & gt; BeginTrans ();//1 

Recordset_ptr=connection_ptr - & gt; Excute (_bstr_t (" select * from table_foo "), & amp; Affected, adCmdText); 

Connection_ptr - & gt; CommitTrans ();//2 

VARIANT_BOOL res=recordset_ptr - & gt; BOF.//3 

. 
} 
The catch (_com_error & amp; E) 
{
E.E rrorMessage (); 
} 
} 

Now the situation is:
If add statements 1 and 2, namely BeginTrans () and CommitTrans (), then execute a statement 3: VARIANT_BOOL res=recordset_ptr - & gt; When the BOF
Jump straight to exception: a catastrophic failure,
If the commented-out statements 1 and 2, namely BeginTrans () and CommitTrans (), so all is well,

All this is how to return a responsibility excuse me? What principle??