[sqlite] utf8 decode

[卢炎君]

Hi guys
   First of all, all data be complied as UTF-8 stored in my DB.
   Second, When   I used sqlite browser tool (from sourceforge)to browsed my 
DB, the result of chinese characters are correct, then I write a function which 
just call sqlite3_column_text inside it, Demo like below:
const char* demo(..)
{
 ...
return (const char*)sqlite3_column_text(mpVM, nField);
 ...
}
BTW, all something on the same DB and same recorde. I found that the same 
result of chinese characters are incorrect,