A project used ADO method making connection to mysql may not work so well and may not so effictive ,  thus , use Mysql C-Api is a rather good scheme , but the C-Api  is rather tougn for beginner , fortunately , An project called Mysql++ lib avaliable for C++ programmer. It's better than C-Api , but there is a problem while using with winsock2 on the platform Ms-windows .
Any question , contact me as follows:

    The problem may appear like this :

c:\program files\devstudio\vc98\include\winsock2.h(99) : error C2011: 'fd_set' : 'struct' type redefinition
c:\program files\devstudio\vc98\include\winsock2.h(134) : warning C4005: 'FD_SET' : macro redefinition
c:\program files\devstudio\vc98\include\winsock.h(83) : see previous definition of 'FD_SET'
c:\program files\devstudio\vc98\include\winsock2.h(143) : error C2011: 'timeval' : 'struct' type redefinition
c:\program files\devstudio\vc98\include\winsock2.h(199) : error C2011: 'hostent' : 'struct' type redefinition
c:\program files\devstudio\vc98\include\winsock2.h(212) : error C2011: 'netent' : 'struct' type redefinition
c:\program files\devstudio\vc98\include\winsock2.h(219) : error C2011: 'servent' : 'struct' type redefinition 

The problem tells its own table , the winsock.h was included somewhere . As we know , using the winsock and winsock2 must notice these :

 

if you use windows.h , you must use like this :

   #define WIN32_LEAN_AND_MEAN
   #include <windows.h>

but , this time , the winsock.h inclued in the diretory /Mysql++ 2.2.3 /lib/Common.h ，What could I do to enable Winsock2 in my project and make no impress on other projects?

this is a unified way to make the things easier and clear - Condition Compiler , you can code like this :


after done , you define _CXL_WINSOCK2  in your project to enable winsock2  or leave it to use winsock.