C++ mySQL connector LINKER errors (Windows) - mysql

Question

I've been trying to get working MySQL example with Visual Studio 2010 on Windows 7 (x64). I don't have problems on Linux, however, I get a lot errors on Windows. This is my code (I've copied from some site to test if it really won't work)
/* Copyright 2008, 2010, Oracle and/or its affiliates. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
There are special exceptions to the terms and conditions of the GPL
as it is applied to this software. View the full text of the
exception in file EXCEPTIONS-CONNECTOR-C++ in the directory of this
software distribution.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/* Standard C++ includes */
#include <stdlib.h>
#include <iostream>
/*
Include directly the different
headers from cppconn/ and mysql_driver.h + mysql_util.h
(and mysql_connection.h). This will reduce your build time!
*/
#include <mysql_connection.h>
#include <driver.h>
#include <exception.h>
#include <resultset.h>
#include <statement.h>
using namespace std;
int main(void)
{
cout << endl;
cout << "Running 'SELECT 'Hello World!' » AS _message'..." << endl;
try {
sql::Driver *driver;
sql::Connection *con;
sql::Statement *stmt;
sql::ResultSet *res;
/* Create a connection */
driver = get_driver_instance();
con = driver->connect("tcp://127.0.0.1:3306", "root", "root");
/* Connect to the MySQL test database */
con->setSchema("test");
stmt = con->createStatement();
res = stmt->executeQuery("SELECT 'Hello World!' AS _message");
while (res->next()) {
cout << "\t... MySQL replies: ";
/* Access column data by alias or column name */
cout << res->getString("_message") << endl;
cout << "\t... MySQL says it again: ";
/* Access column fata by numeric offset, 1 is the first column */
cout << res->getString(1) << endl;
}
delete res;
delete stmt;
delete con;
} catch (sql::SQLException &e) {
cout << "# ERR: SQLException in " << __FILE__;
// cout << "(" << __FUNCTION__ << ") on line " » << __LINE__ << endl;
cout << "# ERR: " << e.what();
cout << " (MySQL error code: " << e.getErrorCode();
cout << ", SQLState: " << e.getSQLState() << " )" << endl;
}
cout << endl;
return EXIT_SUCCESS;
}
hen I tried linking to the static library mysqlcppconn-static.lib. This produces the unresolved errors below. :
1>xedownload.obj : error LNK2019: unresolved external symbol
"__declspec(dllimport) public: class std::basic_string<char,struct
std::char_traits<char>,class std::allocator<char> > const & __thiscall
sql::SQLException::getSQLState(void)const "(__imp_?getSQLState#SQLException#sql##QBEABV?$basic_string#DU?$char_traits#D#std##V?$alloc ator#D#2##std##XZ) referenced in function __catch$_main$0
1>xedownload.obj : error LNK2019: unresolved external symbol "__declspec(dllimport)
public: int __thiscall sql::SQLException::getErrorCode(void)const "(__imp_?getErrorCode#SQLException#sql##QBEHXZ) referenced in function __catch$_main$0
1>xedownload.obj : error LNK2019: unresolved external symbol "__declspec(dllimport)
public: __thiscall sql::SQLString::~SQLString(void)" (__imp_??1SQLString#sql##QAE#XZ) referenced in function _main
1>xedownload.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall sql::SQLString::SQLString(char const * const)" (__imp_??0SQLString#sql##QAE#QBD#Z) referenced in function _main
1>xedownload.obj : error LNK2019: unresolved external symbol __imp__get_driver_instance referenced in function _main
1>xedownload.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const & __thiscall sql::SQLString::asStdString(void)const " (__imp_?asStdString#SQLString#sql##QBEABV?$basic_string#DU?$char_traits#D#std##V?$allocator#D#2##std##XZ) referenced in function "class std::basic_ostream<char,struct std::char_traits<char> > & __cdecl std::operator<<(class std::basic_ostream<char,struct std::char_traits<char> > &,class sql::SQLString const &)" (??6std##YAAAV?$basic_ostream#DU?$char_traits#D#std###0#AAV10#ABVSQLString#sql###Z)
1>c:\users\avi\documents\visual studio 2010\Projects\xedownload\Debug\xedownload.exe : fatal error LNK1120: 6 unresolved externals

Answer 1

I think you are running win32, but in fact your library is 64-bit, so you need to see your system installed MySQL Connector C++ 1.1.6 in which the next, in the end is 64-bit or 32-bit. Running a 32-bit program requires the installation of a 32-bit library, which requires 64-bit libraries and header files to run 64-bit programs. VSxxxx special attention to the development process